Commit Graph

13672 Commits

Author SHA1 Message Date
Linus Torvalds
a13307e97d Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Pull BPF fixes from Daniel Borkmann:

 - Fix BPF verifier to preserve full pointer state for commuted
   scalar += pointer arithmetic (Yiyang Chen, Eduard Zingerman)

 - Fix a use-after-free of request sockets in the BPF TCP iterator
   batching (Jose Fernandez)

 - Fix a use-after-free of sk_redir in the BPF sockmap send verdict
   path (Chengfeng Ye)

 - Fix a netns reference imbalance in the BPF conntrack kfuncs
   (Chengfeng Ye)

 - Fix bpf_get_fsverity_digest() dynptr assumptions and silent
   digest truncation (Eric Biggers)

 - Fix bpf_tcp_{gen,check}_syncookie to check sk_state before
   sk_protocol to make sure it is a full socket (Luxiao Xu)

 - Fix rqspinlock to reset the tail when preserving the queue
   on deadlock (Kumar Kartikeya Dwivedi)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  rqspinlock: Reset tail when preserving queue on deadlock
  bpf: Check sk_state before sk_protocol in bpf_tcp_*_syncookie
  fsverity: Fix silent truncation in bpf_get_fsverity_digest()
  fsverity: Fix bpf_get_fsverity_digest() dynptr assumptions
  bpf: tcp: Fix use-after-free in bpf_iter_tcp_established_batch()
  bpf: Fix netns reference imbalance in conntrack kfuncs
  bpf, sockmap: Fix sk_redir use-after-free in send verdict
  selftests/bpf: Cover commuted pointer state propagation
  bpf: Propagate untrusted pointer state in commuted arithmetic
  bpf: Preserve pointer state for commuted arithmetic
  bpf: Simplify sanitize_err() signature
2026-08-07 08:08:57 -07:00
Jiayuan Chen
a0ab2ba83e tcp: fix TFO max_qlen accounting across reuseport migration
A listener's TCP_FASTOPEN max_qlen stops being accurate and lets through
far more pending Fast Open requests than it was configured for.

This only shows up with SO_REUSEPORT listener migration, where closing a
listener hands its still-pending TFO children over to a surviving one.

fastopenq.qlen is charged in tcp_fastopen_create_child() when the child
is created and uncharged in reqsk_fastopen_remove() when the handshake
completes.  The uncharge follows rsk_listener of the request the child
points at, and inet_reqsk_clone() has repointed the child at a new
request owned by the new listener, so the ++ and the -- land on two
different sockets.  The new listener's qlen drifts negative and its
limit no longer binds.

Charge the new listener during migration, like reqsk_queue_migrated()
already does for queue->young and queue->qlen.

Fixes: 54b92e8419 ("tcp: Migrate TCP_ESTABLISHED/TCP_SYN_RECV sockets in accept queues.")
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260803061739.134737-1-jiayuan.chen@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-05 17:10:28 -07:00
Xuanqiang Luo
d0f86fb36e udp: fix potential use-after-free in tunnel segmentation
__skb_udp_tunnel_segment() gets the UDP header before ensuring the
tunnel header is in the skb head. If the pull reallocates skb->head,
the saved UDP header pointer is no longer valid.

Get the UDP header after the pull to avoid a potential use-after-free.

Fixes: dbef491ebe ("udp: Use uh->len instead of skb->len to compute checksum in segmentation")
Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn>
Reviewed-by: Antoine Tenart <atenart@kernel.org>
Link: https://patch.msgid.link/20260730093554.68127-1-xuanqiang.luo@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-03 18:32:47 -07:00
Zihan Xi
4ff9548d84 ipv4: Fix fib_nlmsg_size() for RTA_VIA nexthops
fib_nlmsg_size() still estimates nexthop space as if every gateway is
encoded as an IPv4 RTA_GATEWAY attribute. IPv4 routes can also carry an
IPv6 gateway, which fib_nexthop_info() dumps as RTA_VIA.

As a result, route notifications can allocate an skb that is too small.
fib_dump_info() then fails with -EMSGSIZE and rtmsg_fib() hits the
WARN_ON() that marks such failures as a fib_nlmsg_size() bug. With
panic_on_warn set, this becomes a kernel panic.

Mirror the actual nexthop dump layout in fib_nlmsg_size(): account for
IPv6 nexthop gateways dumped as RTA_VIA, for the no-header rtnexthop
layout used inside RTA_MULTIPATH, and for RTA_FLOW only when it is
actually present.

Fixes: d15662682d ("ipv4: Allow ipv6 gateway with ipv4 routes")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Signed-off-by: Zihan Xi <zihanx@nebusec.ai>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/6f53fa797fcaeb26966432ed7ae9bb87c4961f37.1785411220.git.zihanx@nebusec.ai
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-03 18:29:50 -07:00
Nathan Gao
0e125ecfe2 tcp: do not change rcv_ssthresh in tcp_measure_rcv_mss()
Commit f5da7c4518 ("tcp: adjust rcvq_space after updating scaling
ratio") replaced the direct window_clamp update in tcp_measure_rcv_mss()
with a call to tcp_set_window_clamp(), a helper that implements the
TCP_WINDOW_CLAMP setsockopt. As a side effect, the helper also shrinks
rcv_ssthresh via __tcp_adjust_rcv_ssthresh().

As a result, each scaling_ratio decrease detected by
tcp_measure_rcv_mss() also cuts rcv_ssthresh. Elsewhere in TCP,
rcv_ssthresh is usually cut under memory pressure and grows via
tcp_grow_window().

Flows whose segment sizes vary keep scaling_ratio oscillating, which
leads to an unstable rcv_ssthresh: a dip of rcv_ssthresh only recovers
via tcp_grow_window(), keeping the advertised window at a relatively
low level even after the ratio itself has recovered, and can even stall
the sender.

Observed on a customer's proxy gateway after upgrading from kernel 6.1
to 6.12: in the worst case, rcv_ssthresh was cut in half by a
scaling_ratio dip. P99 latency jumped from <10ms on 6.1 to ~100ms on
6.12, and almost returned to the 6.1 level with this patch applied.

Restore the plain WRITE_ONCE() update of window_clamp, as introduced
in commit a2cbb16039 ("tcp: Update window clamping condition"), and
keep the rcvq_space.space adjustment. Now rcv_ssthresh is decoupled from
scaling_ratio changes in tcp_measure_rcv_mss().

Fixes: f5da7c4518 ("tcp: adjust rcvq_space after updating scaling ratio")
Signed-off-by: Nathan Gao <zcgao@amazon.com>
Link: https://patch.msgid.link/20260725030806.28135-1-zcgao@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-03 14:20:45 -07:00
Jose Fernandez (Anthropic)
e5fd3f514e bpf: tcp: Fix use-after-free in bpf_iter_tcp_established_batch()
reqsk_queue_hash_req() publishes a TCP_NEW_SYN_RECV request_sock onto
the ehash chain, drops the bucket lock, and only afterwards sets
rsk_refcnt to 3.

Lockless readers such as __inet_lookup_established() handle this with
refcount_inc_not_zero(), but bpf_iter_tcp_established_batch() uses plain
sock_hold() while holding the bucket lock, on the assumption that the
lock guarantees sk_refcnt > 0. That assumption does not hold for
request_sock:

  CPU 0                                CPU 1
  -----                                -----
  tcp_conn_request()
   reqsk_queue_hash_req()
    inet_ehash_insert(req)
     spin_lock(bucket)
     __sk_nulls_add_node_rcu(req)      // rsk_refcnt == 0
     spin_unlock(bucket)
                                       bpf_iter_tcp_established_batch()
                                        spin_lock(bucket)
                                        sock_hold(req)   <-- addition on 0
                                        spin_unlock(bucket)
    refcount_set(&req->rsk_refcnt, 3)  // clobbers saturated value

which surfaces as:

  refcount_t: addition on 0; use-after-free.
  WARNING: lib/refcount.c:25 at refcount_warn_saturate+0x48/0x90, CPU#1
  Call Trace:
   bpf_iter_tcp_established_batch+0x14e/0x170
   bpf_iter_tcp_batch+0x53/0x200
   bpf_iter_tcp_seq_next+0x27/0x70
   bpf_seq_read+0x107/0x410
   vfs_read+0xb9/0x380

The iterator's stolen reference is lost when the publishing CPU's
refcount_set() overwrites the count, leaving the socket one reference
short. When the last legitimate owner drops its reference the reqsk is
freed while still reachable, leading to use-after-free.

This reproduces in seconds with tcp_syncookies=0, a handful of threads
doing connect()/close() to a local listener while others read an
iter/tcp link in a tight loop.

Use refcount_inc_not_zero() and skip the socket on failure. A skipped
socket is still part of the bucket, so keep counting it in expected.
The reallocations are sized from expected, and a request sock whose
refcount gets published while the lock is held across the last realloc
must already have room.

A skipped socket is counted in expected but never batched, so end_sk
can be short of expected on a batch that is actually complete. Decide
completeness by whether the walk left any socket behind instead. The
WARN after the locked realloc checks the same, replacing an
end_sk == expected check that could not hold on that path since
commit cdec67a489 ("bpf: tcp: Make sure iter->batch always
contains a full bucket snapshot").

If every matching socket in a bucket is mid-init (refcount 0), end_sk
stays 0. Advance to the next bucket rather than returning a batch entry
that was never filled this round.

Fixes: 04c7820b77 ("bpf: tcp: Bpf iter batching and lock_sock")
Assisted-by: Claude:unspecified
Signed-off-by: Jose Fernandez (Anthropic) <jose.fernandez@linux.dev>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://lore.kernel.org/bpf/20260730-bpf-iter-tcp-refcnt-v3-1-754b9c8a6717@linux.dev
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-08-03 01:45:01 +02:00
Chengfeng Ye
a766247337 bpf, sockmap: Fix sk_redir use-after-free in send verdict
sk_psock_msg_verdict() takes a socket reference for psock->sk_redir.
tcp_bpf_send_verdict() copies that pointer while holding the source socket
lock, but does not take a reference for the local copy before dropping the
lock around tcp_bpf_sendmsg_redir().

When apply_bytes keeps the cached verdict active, another sendmsg() on the
same source socket can consume the remaining bytes and release the cached
reference while the first thread still holds only the raw local pointer:

  CPU 0                                  CPU 1
  sk_redir = psock->sk_redir
  apply_bytes remains nonzero
  release_sock(sk)
                                         lock_sock(sk)
                                         apply_bytes reaches zero
                                         psock->sk_redir = NULL
                                         release_sock(sk)
                                         tcp_bpf_sendmsg_redir(sk_redir)
                                         sock_put(sk_redir)
  tcp_bpf_sendmsg_redir(sk_redir)

The final sock_put() can free sk_redir before CPU 0 dereferences it.

KASAN reported:

  BUG: KASAN: slab-use-after-free in tcp_bpf_sendmsg_redir+0xf39/0x1020
  Read of size 8 at addr ffff888108537090 by task poc/87
  Call Trace:
   tcp_bpf_sendmsg_redir+0xf39/0x1020
   tcp_bpf_sendmsg+0x977/0x1a50
   __sys_sendto+0x32c/0x3a0
   __x64_sys_sendto+0xdb/0x1b0
  Allocated by task 85:
   sk_prot_alloc+0x56/0x210
   sk_clone+0x6f/0x14b0
   inet_csk_clone_lock+0x24/0x740
   tcp_create_openreq_child+0x25/0x2710
   tcp_v4_syn_recv_sock+0x10a/0xe00
  Freed by task 0:
   __kasan_slab_free+0x43/0x70
   slab_free_after_rcu_debug+0xa6/0x1e0
   rcu_core+0x50a/0x1850
  Last potentially related work creation:
   __sk_destruct+0x3da/0x540
   sk_psock_destroy+0x81e/0xab0
   process_one_work+0x63a/0x1070

Take a temporary socket reference while the source socket lock still
protects psock->sk_redir, and drop it after tcp_bpf_sendmsg_redir()
returns.  This keeps each unlocked use independent of cached-verdict
ownership.

Fixes: 604326b41a ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20260719152207.2892156-1-nicoyip.dev@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-08-01 18:24:58 +02:00
Zhiling Zou
653d7ddf6c inet: frags: publish queues before arming timer
inet_frag_create() arms the fragment queue timer before inserting the
queue into the fqdir rhashtable. If the namespace fragment timeout is
zero or negative, the timer can run before the queue is published.

The timer callback then marks the queue complete, tries to remove a node
that is not in the hash table yet, and drops the anticipated hash
reference. Creation can subsequently publish the completed queue without
restoring that reference, leaving a stale hash node after the caller drops
the remaining reference.

Publish the queue first and arm the timer while holding the queue lock.
This makes timer expiry wait until the queue is visible in the hash table,
so inet_frag_kill() can remove the node and balance the hash reference.

Fixes: 648700f76b ("inet: frags: use rhashtables for reassembly units")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Signed-off-by: Zhiling Zou <zhilinz@nebusec.ai>
Signed-off-by: Ren Wei <enjou1224z@gmail.com>
Link: https://patch.msgid.link/bf66785e7c0c139d7a1900e2f01faeeab344b960.1784948849.git.zhilinz@nebusec.ai
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-31 17:05:07 -07:00
Linus Torvalds
2812e64e15 Merge tag 'net-7.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
 "This is again larger than usual: the backlog accumulated in the past weeks
  is not done yet. I'm not aware of any known pending regression.

  Including fixes from netfilter, Bluetooth, WiFi and CAN.

  Current release - regressions:

   - bluetooth: remove unnecessary hci_conn_get in create_conn_sync

   - can: isotp: fix timer drain order, wakeup handling and tx_gen
     ordering

   - eth:
       - tun/vhost: revert avoid ptr_ring tail-drop when a qdisc is
         present

  Previous releases - regressions:

   - core: do not send ICMP/NDISC Redirects when peer allocation fails

   - ipv6: take nexthop lock for f6i_list walks in replace check and
     notify

   - wifi: fix an ath12k MLO regression impacting WCN7850/QCC2072.

   - netfilter: nf_tables: make nft_object rhltable per table

   - af_unix: fix listen() succeeding on sockets in the wrong state

   - openvswitch: fix potential UAF on meter attach failure

   - bluetooth:
       - fix advertising data UAFs
       - avoid deadlocks in iso_sock_timeout

   - smc: fix socket use-after-free during link group termination

   - dpll: use pin owner's dpll ref for pin-level attribute reporting

   - eth:
       - veth: convert frag_list skbs before running XDP
       - ice: wait for reset completion in ice_resume()
       - igc: remove napi_synchronize() in igc_down()
       - vxlan: use pskb_network_may_pull() for transmit path header pulls

  Previous releases - always broken:

   - xsk: fix AF_XDP multi-buffer Tx descriptor reclaim

   - psp: fix NULL genl_sock deref race with concurrent netns teardown

   - netfilter: widen NAT rewrite delta to s32 in sip_help_tcp()

   - can: peak_usb: fix double free of transfer buffer on URB submit error

   - dibs: fix use-after-free of dmb_node in loopback attach/detach/unregister

   - sctp: prevent peer transport count overflow

   - dsa: mt7530: error out on failed reads in MT7531 PHY polling

   - eth:
       - idpf: bound interrupt-vector register fill to the allocated array"

* tag 'net-7.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (156 commits)
  qede: sync udp_tunnel ports outside qede_lock in the recovery path
  net: openvswitch: fix potential UAF on meter attach failure
  octeontx2-pf: Set correct sequence for carrier off and tx queue stop
  net: libwx: fix FDIR ATR queue mismatch for software VLAN packets
  net: dsa: realtek: use devm_mutex_init for l2_lock
  net: dsa: realtek: use devm_mutex_init for vlan_lock
  net: dsa: realtek: use devm_mutex_init for regmap lock
  net: dsa: realtek: rtl8365mb: use devm_mutex_init for mib_lock
  ptp: netc: fix potential interrupt storm caused by incorrect unbind order
  net: mana: Return error code from mana_create_rxq()
  net: openvswitch: fix skb leak on flow key update failure during ct
  net: openvswitch: fix skb leak on flow key update failure during recirculation
  net: stmmac: Fix E2E delay mechanism
  net: dsa: mt7530: error out on failed reads in MT7531 PHY polling
  net: dsa: mt7530: error out on failed reads in ATC/VTCR command polling
  net: dsa: mt7530: check bus->read() errors in the MDIO regmap backend
  Revert "tun/tap: add ptr_ring consume helper with netdev queue wakeup"
  Revert "vhost-net: wake queue of tun/tap after ptr_ring consume"
  Revert "ptr_ring: move free-space check into separate helper"
  Revert "tun/tap & vhost-net: avoid ptr_ring tail-drop when a qdisc is present"
  ...
2026-07-30 09:18:49 -07:00
Eric Dumazet
080695e6f0 net: udp_tunnel: fix memory leak in udp_tunnel_nic_unregister()
syzbot reported a memory leak [1] in the UDP tunnel NIC offload code.

When device registration fails (e.g. in register_netdevice()), netdev core
unwinds by sending a single NETDEV_UNREGISTER notification. If work was queued
during NETDEV_REGISTER (utn->work_pending is set), udp_tunnel_nic_unregister()
returns early:

	if (utn->work_pending)
		return;

Because failed registrations do not enter netdev_wait_allrefs_any(), no
subsequent NETDEV_UNREGISTER rebroadcast will ever occur. As a result, the
struct udp_tunnel_nic allocated in udp_tunnel_nic_alloc() is leaked
permanently.

Fix this by removing the early return. Instead, synchronously cancel any
pending work with cancel_delayed_work_sync() before freeing @utn.

To be able to call cancel_delayed_work_sync() while holding RTNL (the work also
needs RTNL), switch udp_tunnel_nic_device_sync_work() to rtnl_trylock(). If RTNL
is contended, requeue the work with a 1 jiffy delay (via queue_delayed_work())
to prevent high CPU contention while waiting for RTNL lock.

The utn->work_pending bookkeeping is no longer needed and is removed, as
the workqueue core already tracks the pending/running state of the work.

[1]
BUG: memory leak
unreferenced object 0xffff888127d5f840 (size 96):
  comm "syz-executor", pid 5806, jiffies 4294942188
  backtrace (crc 99fdb6c8):
    __kmalloc_noprof+0x3bf/0x550
    udp_tunnel_nic_alloc net/ipv4/udp_tunnel_nic.c:756 [inline]
    udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:833 [inline]
    udp_tunnel_nic_netdevice_event+0x804/0xab0 net/ipv4/udp_tunnel_nic.c:931
    notifier_call_chain+0x59/0x160 kernel/notifier.c:85
    call_netdevice_notifiers_info+0x7d/0xb0 net/core/dev.c:2250
    register_netdevice+0xc10/0xeb0 net/core/dev.c:11478

Fixes: cc4e3835ef ("udp_tunnel: add central NIC RX port offload infrastructure")
Reported-by: syzbot+eca845fb8c18dd6b44c1@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6a632b15.dde6c935.cf6c8.0011.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260724091137.1792543-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-28 13:32:34 +02:00
Xuanqiang Luo
b14361aca6 fou: Fix use-after-free in fou_create()
fou_create() publishes struct fou through sk_user_data before adding the
new FOU port to the per-netns list.  If fou_add_to_port_list() fails,
the error path frees fou while it is still reachable through
sk_user_data.  A concurrent receive can then dereference the freed
object in fou_from_sock().

This ordering issue was previously noted in the linked discussion.

The failure is reachable when local port 0 is requested.  Each socket
binds to a different ephemeral port, but fou_cfg_cmp() compares the
requested port 0 and reports -EALREADY once an entry already exists.

Release the tunnel socket before freeing fou so sk_user_data is cleared
first, and defer reclamation with kfree_rcu() to protect concurrent RCU
readers.  This matches the lifetime handling in fou_release().

Fixes: 23461551c0 ("fou: Support for foo-over-udp RX path")
Suggested-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://lore.kernel.org/netdev/20260502031401.3557229-12-kuniyu@google.com/
Cc: stable@vger.kernel.org
Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn>
Link: https://patch.msgid.link/20260722083858.182506-1-xuanqiang.luo@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-28 10:40:48 +02:00
Eric Dumazet
dbc3791e3b net: do not send ICMP/NDISC Redirects when peer allocation fails
When inet_getpeer_v4() or inet_getpeer_v6() fails to allocate a peer entry
under memory pressure or tree size caps, redirect handlers previously fell
back to sending un-rate-limited ICMP/NDISC Redirect messages.

In IPv4, ip_rt_send_redirect() called icmp_send() directly when peer == NULL.
In IPv6, ip6_forward() and ndisc_send_redirect() passed a NULL peer into
inet_peer_xrlim_allow(), which returned true when peer == NULL.

Because ICMP/NDISC Redirects are not part of the default global rate limit
mask (sysctl_icmp_ratemask), sending redirects when peer == NULL creates
an un-rate-limited ICMP packet storm.

Fix this by failing closed in ip_rt_send_redirect(), ip6_forward(), and
ndisc_send_redirect() when peer is NULL.

Fixes: 92d8682926 ("inetpeer: Move ICMP rate limiting state into inet_peer entries.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260724072901.1633601-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 13:54:16 -07:00
Linus Torvalds
ae453eef92 Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Pull bpf fixes from Eduard Zingerman:

 - Fix tcp_bpf_sendmsg() error path mistaking a concurrently-freed
   sk_psock->cork for the local temporary message and freeing it again
   (Chengfeng Ye)

 - Reject passing scalar NULL to nonnull arg of a global subprog.

   Previously the verifier did not account for the cases directly
   passing scalars to a global subprog, e.g.: 'global_func(0);' would
   pass even if 'global_func' argument was marked nonnull (Amery Hung)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf, sockmap: Fix cork use-after-free in tcp_bpf_sendmsg()
  selftests/bpf: Test passing scalar NULL to nonnull global subprog
  bpf: Reject passing scalar NULL to nonnull arg of a global subprog
2026-07-24 19:31:12 -07:00
Jakub Kicinski
53658c6f36 Merge tag 'nf-26-07-23' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Pablo Neira Ayuso says:

====================
Netfilter/IPVS fixes for net

The following batch contains Netfilter/IPVS fixes for net. This batch
includes a mix of IPVS follow ups related to Sashiko reports, as well as
crash fixes for connection tracking expectation, helpers, ipset and
nf_tables mostly for old bugs. This also includes a fix for the
flowtable tunnel selftest.

1) Use s32 instead of s16 to calculate the remaining payload containing
   SIP messages, otherwise underflow is possible allowing out-of-bound
   memory access beyond the skb->data area. From Xiang Mei.

2) Fix the counter check in the flowtable selftest for tunnels, from
   Lorenzo Bianconi.

3) Add and use nf_ct_expect_related_pair() to add the RTP and RTCP
   expectations under the expectation lock, this is required by the SIP
   and H.323 NAT helpers. This fixes a possible reinsertion of an
   expectation with the DEAD flag set on while looping to find
   consecutive ports.

4) Fix ipset UaF during table resize by blocking comment updates on
   kernel-side adds. From David Lee.

5) Do not propagate the IP_VS_CONN_F_ONE_PACKET flag when using IPVS
   state synchronization, otherwise reaching stale freed from
   ip_vs_conn struct is possible, Zhiling Zou.

6) Adjust the hn1 hash node when the forwarding method changes between
   MASQ and non-MASQ for an already hashed connection.  This can leave
   stale hash nodes pointing to a freed struct ip_vs_conn and trigger
   UaF while reading /proc/net/ip_vs_conn. From Julian Anastasov.

7) nft_object rhltable needs to be per table, just like chain rhltable,
   otherwise UaF from object lookup path while netns is being released.
   There is also the nlevent path that can reach stale objects. Placing
   this rhltable under the table hierarchy fixes this issue.

8) Reject invalid combined usage of hashlimit tables with and without
   XT_HASHLIMIT_RATE_MATCH flag mode, otherwise access to uninitialized
   .burst field of dsthash_ent is possible.

9) Fix checksum validations in IPVS performed from LOCAL_IN,
   from Julian Anastasov.

10) Fix incorrect packet offset to layer 4 protocol in IPVS, uncovered
    by Sashiko, from Julian Anastasov.

11) Skip the mangling of ICMP replies for non-first fragments, also
    reported by Sashiko. Also from Julian.

12) Clear ip_vs_conn flags under the spinlock to fix a possible data
    race. From Julian Anastasov.

13) Fix incorrect calculation of the payload bitmask in the nf_tables
    hardware offload support, leading to UBSAN splat. From Xiang Mei.

* tag 'nf-26-07-23' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nft_payload: fix mask build for partial field offload
  ipvs: clear the nfct flag under lock
  ipvs: do not mangle ICMP replies for non-first fragments
  ipvs: fix places with wrong packet offsets
  ipvs: fix the checksum validations
  netfilter: xt_hashlimit: validate hashtable supports XT_HASHLIMIT_RATE_MATCH
  netfilter: nf_tables: make nft_object rhltable per table
  ipvs: adjust double hashing when fwd method changes
  ipvs: do not propagate one-packet flag to synced conns
  netfilter: ipset: do not update comments from kernel-side hash adds
  netfilter: nf_conntrack_expect: add and use nf_ct_expect_related_pair()
  selftests: netfilter: nft_flowtable.sh: fix offload counter verification for tunnel tests
  netfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp()
====================

Link: https://patch.msgid.link/20260723163910.274695-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 17:10:54 -07:00
Chengfeng Ye
2d66a03386 bpf, sockmap: Fix cork use-after-free in tcp_bpf_sendmsg()
tcp_bpf_sendmsg() keeps msg_tx across sk_stream_wait_memory(), which
drops and reacquires the socket lock.  Its error path tries to decide
whether msg_tx names the local temporary message by comparing it with
the current value of psock->cork.

This comparison is unsafe when two threads send on the same socket:

  Thread A                         Thread B
  msg_tx = psock->cork
  sk_msg_alloc() fails
  sk_stream_wait_memory()
    releases the socket lock      acquires the socket lock
                                  completes the cork
                                  psock->cork = NULL
                                  frees the cork
    reacquires the socket lock
  msg_tx != psock->cork
  sk_msg_free(msg_tx)

The stale cork is therefore mistaken for the local temporary message
and freed again.  KASAN reported:

  BUG: KASAN: slab-use-after-free in sk_msg_free+0x49/0x50
  Read of size 4 at addr ffff88810c908800 by task poc/90
  Call Trace:
   sk_msg_free+0x49/0x50
   tcp_bpf_sendmsg+0x14f5/0x1cc0
   __sys_sendto+0x32c/0x3a0
   __x64_sys_sendto+0xdb/0x1b0
  Allocated by task 89:
   __kasan_kmalloc+0x8f/0xa0
   tcp_bpf_sendmsg+0x16b3/0x1cc0
  Freed by task 91:
   __kasan_slab_free+0x43/0x70
   kfree+0x131/0x3c0
   tcp_bpf_sendmsg+0xec3/0x1cc0

msg_tx can only name the stack-local tmp or the shared cork. Check for
tmp directly so a changed psock->cork cannot turn a shared message into
an apparent local one.

Fixes: 604326b41a ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/87fr18lmzo.fsf%40cloudflare.com/
Link: https://lore.kernel.org/netdev/20260719161630.2901208-1-nicoyip.dev%40gmail.com/ [v1]
Link: https://patch.msgid.link/20260724103856.3399001-1-nicoyip.dev@gmail.com
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
2026-07-24 15:04:11 -07:00
Xiang Mei (Microsoft)
4787a6d262 nexthop: avoid unlocked f6i_list walk in nh_rt_cache_flush
nh_rt_cache_flush() walks nh->f6i_list during an RTNL-serialized nexthop
replace without holding nh->lock, racing the unlocked IPv6 route
add/delete that mutate the list under nh->lock and free fib6_info
entries (nh_rt_cache_flush() is inlined into rtm_new_nexthop()):

  BUG: KASAN: slab-use-after-free in nh_rt_cache_flush (net/ipv4/nexthop.c:2243)
  Read of size 8 at addr ffff888012953e18 by task exploit/146
   nh_rt_cache_flush (net/ipv4/nexthop.c:2243)
   replace_nexthop (net/ipv4/nexthop.c:2610)
   rtm_new_nexthop (net/ipv4/nexthop.c:3323)
   rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)

Unlike the other f6i_list walks, this one bumps each route's sernum via
fib6_update_sernum_upto_root(), which needs tb6_lock; taking nh->lock
around it would invert the established tb6_lock -> nh->lock order and
deadlock. As the only purpose is to invalidate cached dsts, bump the
IPv6 sernum for the whole netns with rt_genid_bump_ipv6() instead,
mirroring the rt_cache_flush() already done for IPv4 just above.

Fixes: 081efd1832 ("ipv6: Protect nh->f6i_list with spinlock and flag.")
Reported-by: AutonomousCodeSecurity@microsoft.com
Signed-off-by: Xiang Mei (Microsoft) <xmei5@asu.edu>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260722002951.2614721-2-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 15:00:56 -07:00
Xiang Mei (Microsoft)
072cd1f218 nexthop: take nh->lock for f6i_list walks in replace check and notify
fib6_check_nh_list() and __nexthop_replace_notify() walk nh->f6i_list
during an RTNL-serialized nexthop replace without holding nh->lock. IPv6
RTM_NEWROUTE/RTM_DELROUTE run without RTNL and mutate that list under
nh->lock (fib6_add_rt2node_nh(), fib6_purge_rt()), so both walks race a
concurrent route delete that unlinks and frees a fib6_info:

  BUG: KASAN: slab-use-after-free in rt6_fill_node.isra.0 (net/ipv6/route.c:5799)
  Read of size 4 at addr ffff888014607e64 by task exploit/143
   rt6_fill_node.isra.0 (net/ipv6/route.c:5799)
   fib6_rt_update (net/ipv6/route.c:6412)
   __nexthop_replace_notify (net/ipv4/nexthop.c:2542)
   rtm_new_nexthop (net/ipv4/nexthop.c:2554)
   rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)

  BUG: KASAN: slab-use-after-free in fib6_check_nh_list (net/ipv4/nexthop.c:1605)
  Read of size 8 at addr ffff888014a7d068 by task exploit/142
   fib6_check_nh_list (net/ipv4/nexthop.c:1605)
   rtm_new_nexthop (net/ipv4/nexthop.c:2575)
   rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)

Both walks only read the entries and take no tb6_lock, so protect them
with nh->lock; fib6_rt_update() uses gfp_any(), which returns GFP_ATOMIC
under the lock.

Fixes: 081efd1832 ("ipv6: Protect nh->f6i_list with spinlock and flag.")
Reported-by: AutonomousCodeSecurity@microsoft.com
Signed-off-by: Xiang Mei (Microsoft) <xmei5@asu.edu>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260722002951.2614721-1-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 15:00:56 -07:00
Linus Torvalds
d326f83e81 Merge tag 'net-7.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
 "Lots of fixes, double the count even for the 'new normal'. Largely due
  to my time off followed by a networking conference which distracted
  most maintainers (less so the AI generators).

  Including fixes from Bluetooth and WiFi.

  Current release - regressions:

   - wifi: mt76: fix MAC address for non OF pcie cards

  Current release - new code bugs:

   - mptcp: fix BUILD_BUG_ON on legacy ARM config

   - wifi: cfg80211: guard optional PMSR nominal time

  Previous releases - regressions:

   - qrtr: ns: raise node count limit to 512, we arbitrarily picked
     256 as a limit, turns out it was too low for real world deployments

   - vhost-net: fix TX stall when vhost owns virtio-net header

   - eth: amd-xgbe: fix MAC_AUTO_SW handling in CL37 AN

   - wifi: ath12k: fix low MLO RX throughput on WCN7850

  Previous releases - always broken:

   - number of random AI fixes for SCTP, RDS and TIPC protocols

   - more AI-looking fixes for WiFi drivers

   - number of fixes for missing pointer reloading after skb pull

   - reject BPF redirect use from qdisc qevent block

   - tcp: initialize standalone TCP-AO response padding

   - vsock/virtio: collapse receive queue under memory pressure to avoid
     client OOMing the host with tiny messages

   - ipv4: icmp: fill flow parameters in icmp_route_lookup decoy lookup,
     make sure the ICMP response routing follows the routing policy

   - gro: fix double aggregation of flush-marked skbs

   - ovpn: fix various refcount bugs

   - tls: device: push pending open record on splice EOF

   - eth: mlx5:
      - use sender devcom for MPV master-up
      - fix MCIA register buffer overflow on 32 dword reads"

* tag 'net-7.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (234 commits)
  drop_monitor: perform u64_stats updates under IRQ-disabled section
  drop_monitor: fix size calculations for 64-bit attributes
  net: drop_monitor: fix info leak in NET_DM_ATTR_PAYLOAD
  mptcp: fix BUILD_BUG_ON on legacy ARM config
  selftests: mptcp: userspace_pm: fix undefined variable port
  mptcp: fix stale skb->sk reference on subflow close
  mptcp: pm: userspace: fix use-after-free in get_local_id
  mptcp: decrement subflows counter on failed passive join
  mac802154: hold an interface reference across the scan worker
  sctp: don't free the ASCONF's own transport in DEL-IP processing
  phonet: check register_netdevice_notifier() error in phonet_device_init()
  phonet: pep: fix use-after-free in pep_get_sb()
  bnge/bng_re: fix ring ID widths
  tipc: fix integer overflow in tipc_recvmsg() and tipc_recvstream()
  net: airoha: fix ETS channel derivation in airoha_tc_setup_qdisc_ets()
  mctp: check register_netdevice_notifier() error in mctp_device_init()
  ptp: netc: explicitly clear TMR_OFF during initialization
  rds: tcp: unregister sysctl before tearing down listen socket
  ipv6: Change allocation flags to match rcu_read_lock section requirements
  net: slip: serialize receive against buffer reallocation
  ...
2026-07-23 12:58:08 -07:00
Yuxiang Yang
a28c4fcbf7 tcp: challenge ACK for non-exact RST in SYN-RECEIVED
The SYN-RECEIVED request-socket path in tcp_check_req() accepts an
in-window RST without requiring SEG.SEQ to exactly match RCV.NXT.  A
non-exact RST therefore removes the request instead of eliciting a
challenge ACK.

RFC 9293 section 3.10.7.4 applies the RFC 5961 reset check in
SYN-RECEIVED: an exact RST resets the connection, while a non-exact
in-window RST must trigger a challenge ACK and be dropped.

Apply that check before the ACK-field validation, following the RFC
sequence-number, RST, then ACK processing order.  Factor the per-netns
challenge ACK quota out of tcp_send_challenge_ack() so request sockets
can share it.  Use the request socket's send_ack() callback and its own
out-of-window ACK timestamp to send and rate-limit the response.

Reported-by: Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn>
Reported-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Reported-by: Ao Wang <wangao@seu.edu.cn>
Reported-by: Xuewei Feng <fengxw06@126.com>
Reported-by: Qi Li <qli01@tsinghua.edu.cn>
Reported-by: Ke Xu <xuke@tsinghua.edu.cn>
Fixes: 282f23c6ee ("tcp: implement RFC 5961 3.2")
Cc: stable@vger.kernel.org
Signed-off-by: Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260717081443.809393-2-yangyx22@mails.tsinghua.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23 08:27:22 -07:00
Runyu Xiao
18f116931f raw: annotate lockless match fields in raw_v4_match()
raw_v4_match() is a lockless match helper under sk_for_each_rcu(). It
still reads inet->inet_daddr, inet->inet_rcv_saddr and
sk->sk_bound_dev_if with plain loads while bind, connect and
bind-to-device paths can update the same match fields concurrently.

Annotate only those mutable match fields in raw_v4_match(), and do so
at the point of use instead of hoisting the bound-device read before
the earlier short-circuit tests.

Also annotate the raw bind writer and the shared IPv4 datagram connect
writer used by raw sockets, so the address fields updated on bind and
connect match explicit WRITE_ONCE() updates.

This version intentionally leaves the shared disconnect-side IPv4
writers to follow-up cleanup and limits the writer changes here to the
raw bind path and the datagram connect path directly exercised by raw
sockets.

Fixes: 0daf07e527 ("raw: convert raw sockets to RCU")
Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Link: https://patch.msgid.link/20260716142958.3064224-1-runyu.xiao@seu.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23 07:46:12 -07:00
Eric Dumazet
853e164c2b ipv4: icmp: fill flow parameters in icmp_route_lookup decoy lookup
When Linux forwards a packet and needs to generate an ICMP error,
icmp_route_lookup() performs a reverse-path relookup. For non-local
destinations, it performs a decoy lookup to find the expected egress
interface (rt2->dst.dev) before validating the path with ip_route_input().

Currently, the decoy flow structure (fl4_2) only sets .daddr = fl4_dec.saddr,
leaving .saddr, .flowi4_dscp, .flowi4_proto, .flowi4_mark, .flowi4_oif,
.fl4_sport, .fl4_dport, and .flowi4_uid zeroed out.

When policy routing rules (such as ip rule add from $SRC lookup 100, or
dscp/fwmark/ipproto/port rules, or VRF bindings) are configured:
1. The decoy lookup fails to match the policy rule because saddr and other
   key flow selectors are missing in fl4_2.
2. It resolves a route using the default table instead, returning an incorrect
   egress netdev.
3. Passing the wrong netdev to ip_route_input() causes strict reverse-path
   filtering (rp_filter=1) to fail, logging false-positive "martian source"
   warnings and causing the relookup to fail.

Fix this by initializing fl4_2 from fl4_dec and:
- Swapping source/destination IP addresses.
- Swapping L4 ports for transport protocols with ports (TCP, UDP, SCTP, DCCP)
  so port-based policy routing matches correctly. Non-port protocols (such as
  ICMP or GRE) leave the flowi_uli union fields intact to prevent corruption.
- Setting .flowi4_oif = l3mdev_master_ifindex(route_lookup_dev) to ensure
  VRF routing tables are respected.
- Setting .flowi4_flags |= FLOWI_FLAG_ANYSRC to allow output route lookups
  for non-local source IP addresses.
- Using __ip_route_output_key() instead of ip_route_output_key() for fl4_2
  so that raw FIB routing is used without triggering spurious XFRM policy
  lookups on the decoy flow (the actual XFRM lookup is performed later using
  fl4_dec).

Fixes: 415b3334a2 ("icmp: Fix regression in nexthop resolution during replies.")
Reported-by: Muhammad Ziad <muhzi100@gmail.com>
Closes: https://lore.kernel.org/netdev/CAOAwikA60AYKdFr_UDLyja3oU4hqyAE7uFZWqum5uRdaQsgRYg@mail.gmail.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260722104236.2938082-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23 07:01:24 -07:00
Yun Zhou
675ed582c1 net: gre: fix lltx regression for GRE tunnels with SEQ/CSUM
Before commit 00d066a4d4 ("netdev_features: convert NETIF_F_LLTX to
dev->lltx"), NETIF_F_LLTX was set unconditionally in both
__gre_tunnel_init() and ip6gre_tnl_init_features() alongside
GRE_FEATURES:

    dev->features |= GRE_FEATURES | NETIF_F_LLTX;

When that commit converted NETIF_F_LLTX to the dev->lltx flag, it
placed 'dev->lltx = true' after the SEQ/CSUM early returns instead
of before them. This causes GRE/GRETAP/ip6gre tunnels with SEQ or
CSUM+encap to lose lockless TX, reintroducing _xmit_lock acquisition
around their ndo_start_xmit. Since GRE xmit re-enters the stack via
ip_tunnel_xmit(), holding _xmit_lock risks ABBA deadlock with the
underlay device.

  CPU0                        CPU1
  ----                        ----
  lock(&qdisc_xmit_lock_key#6);
                              lock(&qdisc_xmit_lock_key#3);
                              lock(&qdisc_xmit_lock_key#6);
  lock(&qdisc_xmit_lock_key#3);

Fix by moving dev->lltx = true before the early returns in both
functions, restoring the original unconditional behavior.

Fixes: 00d066a4d4 ("netdev_features: convert NETIF_F_LLTX to dev->lltx")
Signed-off-by: Yun Zhou <yun.zhou@windriver.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260713150945.1779628-1-yun.zhou@windriver.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-23 13:01:57 +02:00
Xiang Mei (Microsoft)
980a813452 bpf: tcp: fix double sock release on batch realloc
bpf_iter_tcp_batch() releases the current batch via
bpf_iter_tcp_put_batch(), which drops the socket refs and rewrites
each slot with the socket cookie, then grows the batch. cur_sk/end_sk
are kept for bpf_iter_tcp_resume(), but on realloc failure the function
returns ERR_PTR() before resume runs, leaving cur_sk < end_sk over
slots that now hold cookies rather than sock pointers.
bpf_iter_tcp_seq_stop() then calls bpf_iter_tcp_put_batch() again and
dereferences a cookie as a struct sock.

Empty the batch on the failure path so stop() does not release it
again. The sockets were already freed by the first
bpf_iter_tcp_put_batch(), so nothing leaks, and a later read() rescans
the bucket from the start instead of skipping it. The sibling
GFP_NOWAIT failure path still holds real socket references and is left
for stop() to release.

  BUG: KASAN: null-ptr-deref in __sock_gen_cookie
  Read of size 8 at addr 0000000000000059 by task exploit
   ...
   __sock_gen_cookie (net/core/sock_diag.c:28)
   bpf_iter_tcp_put_batch (net/ipv4/tcp_ipv4.c:2918)
   bpf_iter_tcp_seq_stop (net/ipv4/tcp_ipv4.c:3270)
   bpf_seq_read (kernel/bpf/bpf_iter.c:205)
   vfs_read (fs/read_write.c:572)
   ksys_read (fs/read_write.c:716)
   do_syscall_64
   entry_SYSCALL_64_after_hwframe
  Kernel panic - not syncing: Fatal exception

Fixes: cdec67a489 ("bpf: tcp: Make sure iter->batch always contains a full bucket snapshot")
Reported-by: AutonomousCodeSecurity@microsoft.com
Signed-off-by: Xiang Mei (Microsoft) <xmei5@asu.edu>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jordan Rife <jordan@jrife.io>
Link: https://patch.msgid.link/20260713233230.3553593-1-xmei5@asu.edu
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-23 12:20:34 +02:00
Pablo Neira Ayuso
4aa63842fc netfilter: nf_conntrack_expect: add and use nf_ct_expect_related_pair()
Add a new function to insert a pair of expectations, this is required by
the SIP and H323 NAT helpers. The spinlock is held to check if there is
a slot for both expectations, in such case, insert them.

This removes the need for nf_ct_unexpect_related() inside the loop to
find a pair of consecutive ports, otherwise inserting expectations whose
dead flag is already set on can happen.

Bump master_help->expecting for the expectation class after checking if
the expectation fits in the master expectation list, which is needed for
this new _pair() function variant to run the eviction routine including
the preallocated slot for the first expectation in the pair.

Fixes: b8b09dc2bf ("netfilter: nf_conntrack_expect: use conntrack GC to reap expectations")
Reported-by: Jaeyeong Lee <iostreampy@proton.me>
Link: https://patch.msgid.link/178377968720.33756.12204817361601593230@proton.me/
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-07-22 20:34:28 +02:00
Yizhou Zhao
e1a9d3cc11 tcp: initialize standalone TCP-AO response padding
tcp_v4_send_ack() and tcp_v6_send_response() construct standalone TCP
responses with TCP-AO options.  The option length carries the actual MAC
length, but the TCP header length includes the option rounded up to a
four-byte boundary.

tcp_ao_hash_hdr() writes the MAC only.  Thus, when the MAC length is not
four-byte aligned, the one to three bytes after the MAC are left
uninitialized and may be transmitted.  For the normal TCP-AO hashing
mode, those bytes also have to be initialized before computing the MAC.

Initialize only the alignment padding in the TCP-AO branches, before
hashing the header.  Use TCPOPT_NOP, as in the normal TCP-AO output path.
This avoids adding work to non-AO TCP responses while preserving a valid
authenticated header.

Fixes: decde2586b ("net/tcp: Add TCP-AO sign to twsk")
Fixes: da7dfaa6d6 ("net/tcp: Consistently align TCP-AO option in the header")
Cc: stable@vger.kernel.org
Reported-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Reported-by: Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn>
Reported-by: Ao Wang <wangao@seu.edu.cn>
Reported-by: Xuewei Feng <fengxw06@126.com>
Reported-by: Qi Li <qli01@tsinghua.edu.cn>
Reported-by: Ke Xu <xuke@tsinghua.edu.cn>
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260713105631.8616-1-zhaoyz24@mails.tsinghua.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-21 15:24:36 -07:00
Xiang Mei (Microsoft)
6347c5314c nexthop: initialize extack in nh_res_bucket_migrate()
nh_res_bucket_migrate() passes an uninitialized netlink_ext_ack to
call_nexthop_res_bucket_notifiers(). When
nh_notifier_res_bucket_info_init() fails (e.g. the kzalloc returns
-ENOMEM), the error is propagated back before any notifier sets
extack._msg, and the error path formats the stale pointer with
pr_err_ratelimited("%s\n", extack._msg). With CONFIG_INIT_STACK_NONE
this dereferences uninitialized stack memory:

  Oops: general protection fault, probably for non-canonical address ...
  KASAN: maybe wild-memory-access in range [...]
  RIP: 0010:string (lib/vsprintf.c:730)
   vsnprintf (lib/vsprintf.c:2945)
   _printk (kernel/printk/printk.c:2504)
   nh_res_bucket_migrate (net/ipv4/nexthop.c:1816)
   nh_res_table_upkeep (net/ipv4/nexthop.c:1866)
   rtm_new_nexthop (net/ipv4/nexthop.c:3323)
   rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)
   netlink_sendmsg (net/netlink/af_netlink.c:1900)
  Kernel panic - not syncing: Fatal exception

Zero-initialize extack so _msg is NULL on error paths that never set it.

Fixes: 7c37c7e004 ("nexthop: Implement notifiers for resilient nexthop groups")
Reported-by: AutonomousCodeSecurity@microsoft.com
Signed-off-by: Xiang Mei (Microsoft) <xmei5@asu.edu>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260713221551.3344650-1-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-21 15:09:41 -07:00
Linus Torvalds
94515f3a7d Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Pull bpf fixes from Kumar Kartikeya Dwivedi:

 - Fix a UAF in socket clone early bailout paths (Matt Bobrowski)

 - Reject unhashed UDP sockets on sockmap update to prevent refcount
   leaks (Michal Luczaj)

 - Account for receive queue data in FIONREAD on sockmap sockets without
   a verdict program (Mattia Meleleo)

 - Reject negative constant offsets for verifier buffer pointers (Sun
   Jian)

 - Fix for tracing of kfuncs with implicit arguments (Ihor Solodrai)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Cover tracing implicit kfunc args
  bpf: Fix tracing of kfuncs with implicit args
  selftests/bpf: Cover negative buffer pointer offsets
  bpf: Reject negative const offsets for buffer pointers
  selftests/bpf: Test FIONREAD on a sockmap socket without a verdict program
  bpf, sockmap: Account for receive queue in FIONREAD without a verdict program
  selftests/bpf: Fail unbound UDP on sockmap update
  selftests/bpf: Adapt sockmap update error handling
  bpf, sockmap: Reject unhashed UDP sockets on sockmap update
  selftests/bpf: Ensure UDP sockets are bound
  bpf: Fix UAF in sock clone early bailouts
2026-07-17 12:55:24 -07:00
Eric Dumazet
2c1931a811 tcp: fix TIME_WAIT socket reference leak on PSP policy failure
Release the TIME_WAIT socket reference and jump to discard_it
upon PSP policy failure in both IPv4 and IPv6 receive paths.
This prevents a memory leak of tcp_tw_bucket structures.

Fixes: 659a2899a5 ("tcp: add datapath logic for PSP with inline key exchange")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Daniel Zahka <daniel.zahka@gmail.com>
Link: https://patch.msgid.link/20260710181317.4060230-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-17 11:53:55 +02:00
Mattia Meleleo
04af4efde5 bpf, sockmap: Account for receive queue in FIONREAD without a verdict program
tcp_bpf_ioctl() answers SIOCINQ from psock->msg_tot_len, which only
counts bytes in ingress_msg. Without a stream/skb verdict program
nothing is diverted there: data stays in sk_receive_queue, so FIONREAD
returns 0 even though read() returns data.

Add tcp_inq() to the reported value when the psock has no verdict
program. The two queues are disjoint, so bytes redirected into
ingress_msg from other sockets stay correctly accounted through
msg_tot_len.

Remove unused sk_psock_msg_inq().

Fixes: 929e30f931 ("bpf, sockmap: Fix FIONREAD for sockmap")
Signed-off-by: Mattia Meleleo <mattia.meleleo@coralogix.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20260708-fionread-no-verdict-v3-1-b4ee31b3af53@coralogix.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-07-15 11:10:14 +02:00
Weiming Shi
f2f152e94a ipv4: fib: free fib_alias with kfree_rcu() on insert error path
fib_table_insert() publishes new_fa into the leaf's fa_list with
fib_insert_alias() before calling the fib entry notifiers. When a
notifier fails, the error path removes new_fa with fib_remove_alias()
(hlist_del_rcu) and frees it right away with kmem_cache_free().

fib_table_lookup() walks that list under rcu_read_lock() only, so a
concurrent lookup that already reached new_fa keeps reading it after the
free:

 BUG: KASAN: slab-use-after-free in fib_table_lookup (net/ipv4/fib_trie.c:1601)
 Read of size 1 at addr ffff88810676d4eb by task exploit/297
 Call Trace:
  fib_table_lookup (net/ipv4/fib_trie.c:1601)
  ip_route_output_key_hash_rcu (net/ipv4/route.c:2814)
  ip_route_output_key_hash (net/ipv4/route.c:2705)
  __ip4_datagram_connect (net/ipv4/datagram.c:49)
  udp_connect (net/ipv4/udp.c:2144)
  __sys_connect (net/socket.c:2167)
  __x64_sys_connect (net/socket.c:2173)
  do_syscall_64
  entry_SYSCALL_64_after_hwframe
 which belongs to the cache ip_fib_alias of size 56

Triggering the error path needs CAP_NET_ADMIN and a registered fib
notifier that can reject a route; a netdevsim device whose IPv4 FIB
resource is exhausted is enough.

Free new_fa with alias_free_mem_rcu(), as fib_table_delete() already
does for a fib_alias removed from the trie.

Fixes: a6c76c17df ("ipv4: Notify route after insertion to the routing table")
Reported-by: Xiang Mei <xmei5@asu.edu>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260704171421.1786806-1-bestswngs@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-10 16:00:41 +02:00
Eric Dumazet
3546deaa0c ipv4: igmp: Fix potential memory leaks in igmp_mod_timer() and igmp_stop_timer()
When a timer is deleted and not re-armed in igmp_mod_timer(), or stopped
in igmp_stop_timer(), the code currently decrements the reference counter
of the multicast list entry @im using refcount_dec(&im->refcnt).

However, both functions can be called from the RCU reader path:
- igmp_mod_timer() via igmp_heard_query() -> for_each_pmc_rcu()
- igmp_stop_timer() via igmp_rcv() -> igmp_heard_report()

If the group im was concurrently removed from the list by ip_mc_dec_group(),
its reference count might have already been decremented to 1.

In this case, timer_delete() succeeds, and refcount_dec() decrements
the refcount from 1 to 0. Since refcount_dec() does not free the object
when it hits 0 (unlike ip_ma_put()), the im structure is leaked.

Fix this by using ip_ma_put(im) instead of refcount_dec(&im->refcnt),
and deferring the put until after the spinlock is released.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260705181756.963063-4-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-08 14:41:01 +02:00
Eric Dumazet
7b19c0f81e ipv4: igmp: Fix potential UAF in igmp_gq_start_timer()
A race condition exists between device teardown (inetdev_destroy) and
incoming IGMP query processing (igmp_rcv), leading to a Use-After-Free
in the IGMP timer callback.

During device destruction, inetdev_destroy() drops the primary reference
to in_device, which can drop its refcount to 0. The actual freeing of
in_device memory is deferred via RCU (using call_rcu()).

Concurrently, igmp_rcv() runs under RCU read lock and obtains the
in_device pointer. Because the memory is RCU-protected, CPU-0 can safely
dereference in_device even if its refcount has hit 0.

However, if CPU-0 calls igmp_gq_start_timer() and re-arms the timer, it
attempts to acquire a reference using in_dev_hold(). This increments the
refcount from 0 to 1, triggering a "refcount_t: addition on 0" warning.
Since the in_device memory is still scheduled to be freed after the RCU
grace period (as the free callback does not check the refcount again),
the device is freed while the timer is still armed. When the timer
expires, it accesses the freed memory, causing a kernel panic.

Fix this by using refcount_inc_not_zero() (via a new helper
in_dev_hold_safe()) to prevent acquiring a reference if the device is
already being destroyed. If the refcount is 0, we do not arm the timer.

A similar issue in IPv6 MLD is fixed in a subsequent patch.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Zero Day Initiative <zdi-disclosures@trendmicro.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260705181756.963063-2-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-08 14:41:01 +02:00
Yuyang Huang
7993211bde ipv4: igmp: remove multicast group from hash table on device destruction
When a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through
the multicast list and calls ip_ma_put() on each membership, scheduling
them for RCU reclamation. However, they are not unlinked from the device's
multicast hash table (mc_hash).

Since the device remains published in dev->ip_ptr until after
ip_mc_destroy_dev() completes, concurrent RCU readers traversing mc_hash
can still locate and access the multicast group after its refcount is
decremented. If the RCU callback runs and frees the group while a reader is
accessing it, a use-after-free occurs.

Fix this by unlinking the multicast group from mc_hash using
ip_mc_hash_remove() before scheduling it for reclamation.

BUG: KASAN: slab-use-after-free in ip_check_mc_rcu+0x149/0x3f0
Read of size 4 at addr ffff888009bf1408 by task mausezahn/2276

Call Trace:
 <IRQ>
 dump_stack_lvl+0x67/0x90
 print_report+0x175/0x7c0
 kasan_report+0x147/0x180
 ip_check_mc_rcu+0x149/0x3f0
 udp_v4_early_demux+0x36d/0x12d0
 ip_rcv_finish_core+0xb8b/0x1390
 ip_rcv_finish+0x54/0x120
 NF_HOOK+0x213/0x2b0
 __netif_receive_skb+0x126/0x340
 process_backlog+0x4f2/0xf00
 __napi_poll+0x92/0x2c0
 net_rx_action+0x583/0xc60
 handle_softirqs+0x236/0x7f0
 do_softirq+0x57/0x80
 </IRQ>

Allocated by task 2239:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x72/0x90
 ____ip_mc_inc_group+0x31a/0xa40
 __ip_mc_join_group+0x334/0x3f0
 do_ip_setsockopt+0x16fa/0x2010
 ip_setsockopt+0x3f/0x90
 do_sock_setsockopt+0x1ad/0x300

Freed by task 0:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x40/0x50
 __kasan_slab_free+0x3a/0x60
 __rcu_free_sheaf_prepare+0xd4/0x220
 rcu_free_sheaf+0x36/0x190
 rcu_core+0x8d9/0x12f0
 handle_softirqs+0x236/0x7f0

Fixes: e989707135 ("igmp: hash a hash table to speedup ip_check_mc_rcu()")
Cc: stable@vger.kernel.org
Signed-off-by: Yuyang Huang <yuyanghuang@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260701235014.73505-1-yuyanghuang@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-07 12:15:39 +02:00
Dmitry Safonov
6f6e860e37 tcp: Decrement tcp_md5_needed static branch
In case of early freeing an unwanted TCP-MD5 key on TCP-AO connect(),
md5sig_info is freed right away (and set to NULL). Later, at
the moment of socket destruction, the static branch counter
is not getting decremented.

Add a missing decrement for TCP-MD5 static branch.

Reported-by: Qihang <q.h.hack.winter@gmail.com>
Fixes: 0aadc73995 ("net/tcp: Prevent TCP-MD5 with TCP-AO being set")
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://patch.msgid.link/20260625-tcp-md5-connect-v3-3-1fd313d6c1e0@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-29 18:14:30 -07:00
Michael Bommarito
b74cd55038 tcp: defer md5sig_info kfree past RCU grace period in tcp_connect
The md5+ao reconciliation in tcp_connect() (net/ipv4/tcp_output.c)
has two symmetric branches:

	if (needs_md5) {
		tcp_ao_destroy_sock(sk, false);
	} else if (needs_ao) {
		tcp_clear_md5_list(sk);
		kfree(rcu_replace_pointer(tp->md5sig_info, NULL, ...));
	}

Both branches free a per-socket auth-info object while the socket is
in TCP_SYN_SENT and is already on the inet ehash (inserted by
inet_hash_connect() in tcp_v4_connect()). Both branches are reachable
by softirq RX-path readers that load the corresponding info pointer
via implicit RCU before bh_lock_sock_nested() is taken.

The needs_md5 branch is fixed in the prior patch by re-introducing
the call_rcu() free in tcp_ao_destroy_sock(): the equivalent per-key
loop runs inside tcp_ao_info_free_rcu(), the RCU callback, so by the
time it frees each tcp_ao_key all softirq readers that captured the
container have already completed rcu_read_unlock().

The needs_ao branch is not symmetric in the same way. The container
free can be deferred via kfree_rcu(md5sig, rcu) -- struct
tcp_md5sig_info already has the required rcu member
(include/net/tcp.h:1999-2002), and the rest of the tree already does
this in the tcp_md5sig_info_add() rollback paths
(net/ipv4/tcp_ipv4.c:1410, 1436). But the per-key teardown is done
by tcp_clear_md5_list() in process context BEFORE the container's
RCU grace period: it walks &md5sig->head and frees each
tcp_md5sig_key with bare hlist_del + kfree. A concurrent softirq
reader in __tcp_md5_do_lookup() / __tcp_md5_do_lookup_exact()
(tcp_ipv4.c:1253, 1298) walks the same list via
hlist_for_each_entry_rcu() and races with that bare kfree on the
keys themselves -- a per-key slab use-after-free of the same class
as the TCP-AO bug, on the same race window.

Fix this in two halves:

  1. Convert the bare kfree() in tcp_connect() to kfree_rcu() so the
     md5sig_info container joins the rest of the md5sig lifecycle.
     The local-variable lift is mechanical and required because
     kfree_rcu() is a macro that expects an lvalue.

  2. Make tcp_clear_md5_list() RCU-safe by replacing hlist_del +
     kfree(key) with hlist_del_rcu + kfree_rcu(key, rcu). struct
     tcp_md5sig_key already carries the rcu member
     (include/net/tcp.h:1995) and tcp_md5_do_del()
     (net/ipv4/tcp_ipv4.c:1456) already uses kfree_rcu, so this
     restores the lifecycle invariant the rest of the file follows
     rather than introducing a one-off.

The other caller of tcp_clear_md5_list() is tcp_md5_destruct_sock()
(net/ipv4/tcp.c:412), which runs from the sock destructor when the
socket is already unhashed and unreachable; the extra grace period
there is unnecessary but harmless. Making the helper unconditionally
RCU-safe is the cleaner contract.

The needs_ao branch is not reachable by the userns reproducer used
to demonstrate the AO-side splat (the repro installs both keys but
ends up in the needs_md5 branch because the connect peer matches
the MD5 key, not the AO key); however the symmetric race exists
and a maintainer touching this code should not have to think about
which branch escapes RCU and which one does not.

Fixes: 51e547e8c8 ("tcp: Free TCP-AO/TCP-MD5 info/keys without RCU")
Cc: stable@vger.kernel.org # v6.18+
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Reviewed-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
[also credits to Qihang, who found that this races with tcp-diag]
Reported-by: Qihang <q.h.hack.winter@gmail.com>
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://patch.msgid.link/20260625-tcp-md5-connect-v3-2-1fd313d6c1e0@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-29 18:14:30 -07:00
Michael Bommarito
8bc4d43bcc tcp: restore RCU grace period in tcp_ao_destroy_sock
Commit 51e547e8c8 ("tcp: Free TCP-AO/TCP-MD5 info/keys without RCU")
removed the call_rcu() callback from tcp_ao_destroy_sock(), arguing that
"the destruction of info/keys is delayed until the socket destructor"
and therefore "no one can discover it anymore".

That argument does not hold for the call site in tcp_connect()
(net/ipv4/tcp_output.c:4327-4332). At that point the socket is in
TCP_SYN_SENT, has already been inserted into the inet ehash by
inet_hash_connect() in tcp_v4_connect(), and is therefore very much
discoverable: any softirq running tcp_v4_rcv() on another CPU can take
the socket out of the ehash, walk into tcp_inbound_hash(), and load
tp->ao_info via implicit RCU before bh_lock_sock_nested() is taken on
the destroying CPU.

The reader path then enters __tcp_ao_do_lookup() (net/ipv4/tcp_ao.c:208)
which re-loads tp->ao_info via rcu_dereference_check(); the re-load can
still observe the (about-to-be-freed) pointer because there is no
synchronize_rcu() between rcu_assign_pointer(tp->ao_info, NULL) and
tcp_ao_info_free() in tcp_ao_destroy_sock(). The captured pointer is
then walked at line 223:

	hlist_for_each_entry_rcu(key, &ao->head, node, ...)

The writer's synchronous kfree() is free to complete between the line
218 re-fetch and the line 223 hlist iteration. The slab is reused
(or simply LIST_POISON1-stamped if not yet reused) and the iteration
walks attacker-controlled or poison memory in softirq context.

Reproducer (no debug shim, stock x86_64 v7.1-rc2 SMP+KASAN, QEMU+KVM):
an unprivileged uid=1000 process inside CLONE_NEWUSER|CLONE_NEWNET
installs TCP_MD5SIG + TCP_AO_ADD_KEY on a TCP socket, sprays forged
TCP-AO segments toward its eventual 4-tuple via raw sockets, then
calls connect(). The md5-wins reconciliation in tcp_connect() fires
tcp_ao_destroy_sock(); the softirq backlog reader on the loopback
NAPI path crashes on the freed ao->head.first walk:

  Oops: general protection fault, probably for non-canonical
    address 0xfbd59c000000002f
  KASAN: maybe wild-memory-access in range
    [0xdead000000000178-0xdead00000000017f]
  CPU: 0 UID: 1000 PID: 100 Comm: repro_userns
  RIP: 0010:__tcp_ao_do_lookup+0x107/0x1c0
  Call Trace: <IRQ>
    __tcp_ao_do_lookup+0x107/0x1c0
    tcp_ao_inbound_lookup.constprop.0+0x12a/0x200
    tcp_inbound_ao_hash+0x5ea/0x1520
    tcp_inbound_hash+0x7ce/0x1240
    tcp_v4_rcv+0x1e7a/0x3e10
    ...

Restore the RCU grace period: re-add struct rcu_head to tcp_ao_info
and replace the synchronous tcp_ao_info_free() with a call_rcu()
callback. Readers that captured tp->ao_info before rcu_assign_pointer
NULLed it now see the object remain valid until rcu_read_unlock().
With the patch applied the reproducer runs cleanly for 2000 iterations
on the same kernel build.

Fixes: 51e547e8c8 ("tcp: Free TCP-AO/TCP-MD5 info/keys without RCU")
Cc: stable@vger.kernel.org # v6.18+
Reviewed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://patch.msgid.link/20260625-tcp-md5-connect-v3-1-1fd313d6c1e0@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-29 18:14:30 -07:00
Linus Torvalds
805185b7c7 Merge tag 'net-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
 "Including fixes from netfilter and IPsec.

  Current release - regressions:

   - do not acquire dev->tx_global_lock in netdev_watchdog_up()

   - ethtool: keep rtnl_lock for ops using ethtool_op_get_link()

   - fix deadlock in nested UP notifier events

  Current release - new code bugs:

   - eth:
      - cn20k: fix subbank free list indexing for search order
      - airoha: fix BQL underflow in shared QDMA TX ring

  Previous releases - regressions:

   - netfilter:
     - flowtable: fix offloaded ct timeout never being extended
     - nf_conncount: prevent connlimit drops for early confirmed ct

  Previous releases - always broken:

   - require CAP_NET_ADMIN in the originating netns when modifying
     cross-netns devices

   - report NAPI thread PID in the caller's pid namespace

   - mac802154: fix dirty frag in in-place crypto for IOT radios

   - sctp: hold socket lock when dumping endpoints in sctp_diag, avoid
     an overflow

   - eth: gve: fix header buffer corruption with header-split and HW-GRO

   - af_key: initialize alg_key_len for IPComp states, prevent OOB read"

* tag 'net-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (213 commits)
  selftests: bonding: add a test for VLAN propagation over a bonded real device
  vlan: defer real device state propagation to netdev_work
  net: add the driver-facing netdev_work scheduling API
  net: turn the rx_mode work into a generic netdev_work facility
  net: ethtool: keep rtnl_lock for ops using ethtool_op_get_link()
  rxrpc: Fix rxrpc_rotate_tx_rotate() to check there's something to rotate
  rxrpc: Fix leak of released call in recvmsg(MSG_PEEK)
  rxrpc: Fix socket notification race
  rxrpc: Fix potential infinite loop in rxrpc_recvmsg()
  rxrpc: Fix oob challenge leak in cleanup after notification failure
  rxrpc: Fix the reception of a reply packet before data transmission
  afs: Fix uncancelled rxrpc OOB message handler
  afs: Fix further netns teardown to cancel the preallocation charger
  rxrpc: Fix double unlock in rxrpc_recvmsg()
  rxrpc: Fix leak of connection from OOB challenge
  rxrpc: Fix ACKALL packet handling
  net: hns3: differentiate autoneg default values between copper and fiber
  net: hns3: fix permanent link down deadlock after reset
  net: hns3: refactor MAC autoneg and speed configuration
  net: hns3: unify copper port ksettings configuration path
  ...
2026-06-25 12:25:36 -07:00
Eric Dumazet
ecf69d4b43 net: udp_tunnel: prevent double queueing in udp_tunnel_nic_device_sync
Yue Sun reported a use-after-free and debugobjects warning in
udp_tunnel_nic_device_sync_work() during concurrent device operations.

The workqueue core clears the internal pending bit before invoking the
worker. At that point, a concurrent thread can queue the work again.
When the already running worker eventually clears the work_pending flag
to 0, it mistakenly clears the flag for the newly queued instance.
udp_tunnel_nic_unregister() then observes work_pending as 0 and frees
the structure while the second work item is still active in the queue,
leading to UAF.

Fix this by returning early in udp_tunnel_nic_device_sync() if
work_pending is already set, preventing redundant work queueing.

Fixes: cc4e3835ef ("udp_tunnel: add central NIC RX port offload infrastructure")
Reported-by: Yue Sun <samsun1006219@gmail.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260625065938.654652-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25 08:35:51 -07:00
HanQuan
5ba9950bc9 net/tcp-ao: fix use-after-free of key in del_async path
In tcp_ao_delete_key(), the del_async path skips the current_key
and rnext_key validity checks present in the synchronous path,
assuming these pointers are always NULL on LISTEN sockets.  However,
if a key was added with set_current=1/set_rnext=1 while the socket
was in CLOSE state, current_key and rnext_key will be non-NULL
after listen() transitions the socket to LISTEN.

When such a key is deleted with del_async=1, hlist_del_rcu() and
call_rcu() free the key without clearing the dangling pointers.
After the RCU grace period, getsockopt(TCP_AO_INFO) dereferences
current_key->sndid and rnext_key->rcvid from freed slab memory.

Clear current_key and rnext_key in the del_async path when they
reference the key being deleted.

Fixes: d6732b95b6 ("net/tcp: Allow asynchronous delete for TCP-AO keys (MKTs)")
Signed-off-by: HanQuan <eilaimemedsnaimel@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260623015208.1191687-1-eilaimemedsnaimel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-24 19:25:35 -07:00
Jakub Kicinski
e9deb406c1 Merge tag 'ipsec-2026-06-22' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec
Steffen Klassert says:

====================
pull request (net): ipsec 2026-06-22

1) xfrm: use compat translator only for u64 alignment mismatch
   Gate the XFRM_USER_COMPAT translator on COMPAT_FOR_U64_ALIGNMENT
   so 32-bit compat tasks on arches whose 32-bit ABI already matches
   the native 64-bit layout are no longer rejected with -EOPNOTSUPP.
   From Sanman Pradhan.

2) net: af_key: initialize alg_key_len for IPComp states
   Initialize the alg_key_len to 0 in the IPComp branch of
   pfkey_msg2xfrm_state() so an uninitialized value cannot drive
   xfrm_alg_len() into a slab-out-of-bounds kmemdup during
   XFRM_MSG_MIGRATE. From Zijing Yin.

3) xfrm: Fix dev use-after-free in xfrm async resumption
   Stash the original skb->dev and extend the RCU critical section
   across xfrm_rcv_cb() and transport_finish() to prevent a
   tunnel-device UAF and original-device refcount leak when a
   callback replaces skb->dev. From Dong Chenchen.

4) xfrm: Fix xfrm state cache insertion race
   Move the state-validity check inside xfrm_state_lock in the
   input state cache insertion path so a state cannot be killed
   between the check and the insert. From Herbert Xu.

5) xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[]
   Add READ_ONCE()/WRITE_ONCE() annotations on xfrm_policy_count
   and xfrm_policy_default to silence the KCSAN data race reported
   on net->xfrm.policy_count. From Eric Dumazet.

6) espintcp: use sk_msg_free_partial to fix partial send
   Replace the manual skmsg accounting in espintcp with
   sk_msg_free_partial() so the skmsg stays consistent on every
   iteration and the partial-send accounting bugs go away.
   From Sabrina Dubroca.

7) xfrm: validate selector family and prefixlen during match
   Reject mismatched address families in xfrm_selector_match() and
   bound prefixlen in addr4_match()/addr_match() to prevent the
   shift-out-of-bounds syzbot reported when an AF_UNSPEC selector
   with a large prefixlen is matched against an IPv4 flow.
   From Eric Dumazet.

* tag 'ipsec-2026-06-22' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec:
  xfrm: validate selector family and prefixlen during match
  espintcp: use sk_msg_free_partial to fix partial send
  xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[]
  xfrm: Fix xfrm state cache insertion race
  xfrm: Fix dev use-after-free in xfrm async resumption
  net: af_key: initialize alg_key_len for IPComp states
  xfrm: use compat translator only for u64 alignment mismatch
====================

Link: https://patch.msgid.link/20260622075726.29685-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23 16:22:24 -07:00
Jakub Kicinski
56abdaebbf Merge tag 'nf-26-06-21' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net. This batches
fixes for real crashes with trivial/correctness fixes. There is too
a rework of the conntrack expectation timeout strategy to deal with
a possible race when removing an expectation.

1) Fix the incorrect flowtable timeout extension for entries in
   hw offload, from Adrian Bente. This is correcting a defect in
   the functionality, no crash.

2) Hold reference to device under the fake dst in br_netfilter,
   from Haoze Xie. This is fixing a possible UaF if the device
   is removed while packet is sitting in nfqueue.

3) Reject template conntrack in xt_cluster, otherwise access to
   uninitialize conntrack fields are possible leading to WARN_ON
   due to unset layer 3 protocol. From Wyatt Feng.

4) Make sure the IPv6 tunnel header is in the linear skb data
   area before pulling. While at it remove incomplete NEXTHDR_DEST
   support. From Lorenzo Bianconi. This possibly leading to crash
   if IPv4 header is not in the linear area.

5) Use test_bit_acquire in ipset hash set to avoid reordering
   of subsequent memory access. This is addressing a LLM related
   report, no crash has been observed. From Jozsef Kadlecsik.

6) Use test_bit_acquire in ipset bitmap set too, for the same
   reason as in the previous patch, from Jozsef Kadlecsik.

7) Call kfree_rcu() after rcu_assign_pointer() to address a
   possible UaF if kfree_rcu() runs inmediately, which to my
   understanding never happens. Never observed in practise,
   reported by LLM. Also from Jozsef Kadlecsik.

8) Use disable_delayed_work_sync() instead cancel_delayed_work_sync()
   to avoid that ipset GC handler re-queues work as reported by LLM.
   From Jozsef Kadlecsik. This is for correctness.

9) Restore the check in nft_payload for exceeding payloda offset
    over 2^16. From Florian Westphal. This fixes a silent truncation,
    not a big deal, but better be assertive and reject it.

10) Validate NFT_META_BRI_IIFHWADDR can only run from bridge
    prerouting. From Florian Westphal. Harmless but it could allow
    to read bytes from skb->cb.

11) Zero out destination hardware address during the flowtable
    path setup, also from Florian. This is a correctness fix, LLM
    points that possible infoleak can happen but topology to achieve
    it is not clear.

12) Skip IPv4 options if present when building the IPV4 reject reply.
    Otherwise bytes in the IPv4 options header can be sent back to
    origin where the ICMP header is being expected. Again from
    Florian Westphal.

13) Replace timer API for expectation by GC worker approach. This
    is implicitly fixing a race between nf_ct_remove_expectations()
    which might fail to remove the expectation due to timer_del()
    returning false because timer has expired and callback is
    being run concurrently. This fix is addressing a crash that has
    been already reported with a reproducer.

14) Check if br_vlan_get_pvid_rcu() fails, otherwise possible stack
    infoleak of 4-bytes. From Florian Westphal.

* tag 'nf-26-06-21' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nft_meta_bridge: fix NFT_META_BRI_IIFPVID stack leak
  netfilter: nf_conntrack_expect: use conntrack GC to reap expectations
  netfilter: nf_reject: skip iphdr options when looking for icmp header
  netfilter: nft_flow_offload: zero device address for non-ether case
  netfilter: nft_meta_bridge: add validate callback for get operations
  netfilter: nft_payload: reject offsets exceeding 65535 bytes
  netfilter: ipset: make sure gc is properly stopped
  netfilter: ipset: fix order of kfree_rcu() and rcu_assign_pointer()
  netfilter: ipset: Don't use test_bit() in lockless RCU readers in bitmap types
  netfilter: ipset: Don't use test_bit() in lockless RCU readers in hash types
  netfilter: flowtable: fix and simplify IP6IP6 tunnel handling
  netfilter: xt_cluster: reject template conntracks in hash match
  netfilter: nf_queue: pin bridge device while NFQUEUE holds fake dst
  netfilter: flowtable: fix offloaded ct timeout never being extended
====================

Link: https://patch.msgid.link/20260620222738.112506-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-22 10:33:38 -07:00
Wongi Lee
eca856950f ipv4: account for fraggap on the paged allocation path
In __ip_append_data(), when the paged-allocation branch is taken,
alloclen and pagedlen are computed as

	alloclen = fragheaderlen + transhdrlen;
	pagedlen = datalen - transhdrlen;

datalen already includes fraggap, but the fraggap bytes carried over
from the previous skb are copied into the new skb's linear area at
offset transhdrlen by the subsequent skb_copy_and_csum_bits(). The
linear area is therefore undersized by fraggap bytes while pagedlen is
overstated by the same amount.

The non-paged branch sets alloclen to fraglen, which already accounts
for fraggap because datalen does. Bring the paged branch in line by
adding fraggap to alloclen and subtracting it from pagedlen.

After this adjustment, copy no longer collapses to -fraggap on the
paged path, so remove the stale comment describing that old arithmetic.

Fixes: 8eb77cc739 ("ipv4: avoid partial copy for zc")
Signed-off-by: Jungwoo Lee <jwlee2217@gmail.com>
Signed-off-by: Wongi Lee <qw3rtyp0@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/ajFR1eLAIs42TN3g@DESKTOP-19IMU7U.localdomain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-21 15:24:49 -07:00
Florian Westphal
af8d6ae09c netfilter: nf_reject: skip iphdr options when looking for icmp header
Not a big deal but this hould have used the real ip header length and not the
base header size.  As-is, if there are options then
nf_skb_is_icmp_unreach() result will be random.

Fixes: db99b2f2b3 ("netfilter: nf_reject: don't reply to icmp error messages")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-21 00:18:27 +02:00
Wyatt Feng
efb8763d7b net: ipv4: bound TCP reordering sysctl writes and MTU probe sizes
Reject invalid `net.ipv4.tcp_reordering` values before they reach TCP
socket state. The sysctl is stored as an `int` but copied into the
`u32` `tp->reordering` field for new sockets, so negative writes wrap
to large values.

With `tcp_mtu_probing=2`, the wrapped value can overflow the
`tcp_mtu_probe()` size calculation and drive the MTU probing path into
an out-of-bounds read. Route `tcp_reordering` writes through
`proc_dointvec_minmax()` and require it to be at least 1. Also require
`tcp_max_reordering` to be at least 1 so the configured maximum cannot
become negative either.

When registering the table for a non-init network namespace, relocate
`extra2` pointers that refer into `init_net.ipv4` so the
`tcp_reordering` upper bound follows that namespace's
`tcp_max_reordering`.

Harden `tcp_mtu_probe()` itself by computing `size_needed` as `u64`.
This keeps the send queue and window checks from being bypassed through
signed integer overflow.

Fixes: 91cc17c0e5 ("[TCP]: MTUprobe: receiver window & data available checks fixed")
Cc: stable@vger.kernel.org
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Zhengchuan Liang <zcliangcn@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Wyatt Feng <bronzed_45_vested@icloud.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/1a5b7e1ef4d70fbad8c8ee0b82d8405f3c964a3d.1781395200.git.bronzed_45_vested@icloud.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-17 16:35:13 -07:00
Maoyi Xie
95cceadbfd net: ip_vti: require CAP_NET_ADMIN in the device netns for changelink
vti_changelink() operates on at most two netns, dev_net(dev) and the
tunnel link netns t->net. They differ once the device is created in or
moved to a netns other than the one the request runs in. The rtnl
changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a
caller privileged there but not in t->net can rewrite a tunnel that
lives in t->net.

Gate vti_changelink() on rtnl_dev_link_net_capable() at its top,
before any attribute is parsed.

Reported-by: Xiao Liang <shaw.leon@gmail.com>
Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/
Fixes: 895de9a348 ("vti4: Enable namespace changing")
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260612085941.3158249-4-maoyixie.tju@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-17 16:01:52 -07:00
Maoyi Xie
8211a26324 net: ipip: require CAP_NET_ADMIN in the device netns for changelink
ipip_changelink() operates on at most two netns, dev_net(dev) and the
tunnel link netns t->net. They differ once the device is created in or
moved to a netns other than the one the request runs in. The rtnl
changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a
caller privileged there but not in t->net can rewrite a tunnel that
lives in t->net.

Gate ipip_changelink() on rtnl_dev_link_net_capable() at its top,
before any attribute is parsed.

Reported-by: Xiao Liang <shaw.leon@gmail.com>
Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/
Fixes: 6c742e714d ("ipip: add x-netns support")
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260612085941.3158249-3-maoyixie.tju@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-17 16:01:52 -07:00
Maoyi Xie
8165f7ff57 net: ip_gre: require CAP_NET_ADMIN in the device netns for changelink
A tunnel changelink() operates on at most two netns, dev_net(dev) and
the tunnel link netns t->net. They differ once the device is created in
or moved to a netns other than the one the request runs in. The rtnl
changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a
caller privileged there but not in t->net can rewrite a tunnel that
lives in t->net.

Add rtnl_dev_link_net_capable() next to rtnl_get_net_ns_capable() in
net/core/rtnetlink.c. It requires CAP_NET_ADMIN in the link netns and is
skipped when the link netns is dev_net(dev), where the rtnl path already
checked it. The other patches in this series use the same helper.

Gate ipgre_changelink() and erspan_changelink() with it, at the top of
the op before any attribute is parsed, because the parsers update live
tunnel fields first. ipgre_netlink_parms() sets t->collect_md before
ip_tunnel_changelink() runs.

Commit 8b484efd5c ("ip6: vti: Use ip6_tnl.net in
vti6_siocdevprivate().") added the same check on the ioctl path. This
adds it on RTM_NEWLINK.

Reported-by: Xiao Liang <shaw.leon@gmail.com>
Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/
Fixes: b57708add3 ("gre: add x-netns support")
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260612085941.3158249-2-maoyixie.tju@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-17 16:01:52 -07:00
Linus Torvalds
9c87e61e3c Merge tag 'bpf-next-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
 "Major changes:

   - Recover from BPF arena page faults using a scratch page and add
     ptep_try_set() for lockless empty-slot installs on x86 and arm64.

     This allows BPF kfuncs to access arena pointers directly.

     The 'arena_direct_access' stable branch was created for this work
     and was pulled into sched-ext and bpf-next trees (Tejun Heo, Kumar
     Kartikeya Dwivedi)

   - Lift old restriction and support 6+ arguments in BPF programs and
     kfuncs on x86 and arm64 (Yonghong Song, Puranjay Mohan)

  Other features and fixes:

   - Add 24-bit BTF vlen and reclaim unused bits in the BTF UAPI to ease
     addition of new BTF kinds (Alan Maguire)

   - Raise the maximum BPF call chain depth from 8 to 16 frames (Alexei
     Starovoitov)

   - Refactor object relationship tracking in the verifier and fix a
     dynptr use-after-free bug (Amery Hung)

   - Harden the signed program loader and reject exclusive maps as inner
     maps (Daniel Borkmann)

   - Replace the verifier min/max bounds fields with a circular number
     (cnum) representation and improve 32->64 bit range refinements
     (Eduard Zingerman)

   - Introduce the arena library and runtime (libarena) with a buddy
     allocator, rbtree and SPMC queue data structures, ASAN support and
     a parallel test harness. Allow subprograms to return arena pointers
     and switch to a BTF type-tag based __arena annotation (Emil
     Tsalapatis)

   - Cache build IDs in the sleepable stackmap path and avoid faultable
     build ID reads under mm locks (Ihor Solodrai)

   - Introduce the tracing_multi link to attach a single BPF program to
     many kernel functions at once. Allow specifying the uprobe_multi
     target via FD (Jiri Olsa)

   - Extend the bpf_list family of kfuncs with bpf_list_add/del(), and
     bpf_list_is_first/is_last/empty() (Kaitao Cheng)

   - Extend the BPF syscall with common attributes support for
     prog_load, btf_load and map_create (Leon Hwang)

   - Wrap rhashtable as BPF map (Mykyta Yatsenko, Herbert Xu)

   - Add sleepable support for tracepoint programs and fix deadlocks in
     LRU map due to NMI reentry (Mykyta Yatsenko)

   - Fix OOB access in bpf_flow_keys, fix nullness analysis of inner
     arrays, enforce write checks for global subprograms (Nuoqi Gui)

   - Report the maximum combined stack depth and print a breakdown of
     instructions processed per subprogram (Paul Chaignon)

   - Add an XDP load-balancer benchmark and arm64 JIT support for stack
     arguments (Puranjay Mohan)

   - Add kfuncs to traverse over wakeup_sources (Samuel Wu)

   - Allow sleepable BPF programs to use LPM trie maps directly (Vlad
     Poenaru)

   - Many more fixes and cleanups across the verifier, BTF, sockmap,
     devmap, bpffs, security hooks, s390/riscv/loongarch JITs,
     rqspinlock, libbpf, bpftool, selftests"

* tag 'bpf-next-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (336 commits)
  selftests/bpf: Work around llvm stack overflow in crypto progs
  selftests/bpf: add test for bpf_msg_pop_data() overflow
  bpf, sockmap: fix integer overflow in bpf_msg_pop_data() bounds check
  sockmap: Fix use-after-free in udp_bpf_recvmsg()
  bpf, sockmap: keep sk_msg copy state in sync
  bpf, sockmap: Fix wrong rsge offset in bpf_msg_push_data()
  bpf, sockmap: reject overflowing copy + len in bpf_msg_push_data()
  selftsets/bpf: Retry map update on helper_fill_hashmap()
  selftests/bpf: Add test for sleepable lsm_cgroup rejection
  selftests/bpf: Add test to verify the fix for bpf_setsockopt() helper
  bpf: Fix bpf_get/setsockopt to tos for ipv4-mapped ipv6 socket
  selftests/bpf: Avoid static LLVM linking for cross builds
  selftests/bpf: Use common CFLAGS for urandom_read
  selftests/bpf: Initialize operation name before use
  tools/bpf: build: Append extra cflags
  libbpf: Initialize CFLAGS before including Makefile.include
  bpftool: Append extra host flags
  bpftool: Avoid adding EXTRA_CFLAGS to HOST_CFLAGS
  bpftool: Pass host flags to bootstrap libbpf
  selftests/bpf: correct CONFIG_PPC64 macro name in comment
  ...
2026-06-17 09:18:14 +01:00
Kuniyuki Iwashima
d954a67a7d ipv4: fib_rule: Move fib4_rules_exit() to ->exit().
syzbot reported use-after-free of net->ipv4.rules_ops. [0]

It can be reproduced with these commands:

  while true; do
  	ip netns add ns1
  	ip -n ns1 link set dev lo up
  	ip -n ns1 address add 192.0.2.1/24 dev lo
  	ip -n ns1 link add name dummy1 up type dummy
  	ip -n ns1 address add 198.51.100.1/24 dev dummy1
  	ip -n ns1 rule add ipproto tcp sport 12345 table 12345
  	ip -n ns1 fou add port 5555 ipproto 47 local 192.0.2.1 peer 198.51.100.2 peer_port 54321
  	ip netns del ns1
  done

The cited commit moved fib4_rules_exit() earlier to ->exit_rtnl(),
but the kernel socket destroyed in ->exit() could eventually reach
__fib_lookup().

I left fib4_rules_exit() in ->exit_rtnl() because fib4_rule_delete()
calls fib_unmerge(), which requires RTNL.

However, when ->delete() is called, ->configure() has already been
called, thus fib_unmerge() in ->delete() has no effect.

Let's remove fib_unmerge() in fib4_rule_delete() and move
fib4_rules_exit() to ->exit().

Many thanks to Ido Schimmel for providing the nice repro very quickly.

Note that we can make fib_rules_ops.delete() return void once
net-next opens.

[0]:
BUG: KASAN: slab-use-after-free in fib_rules_lookup+0x15e/0xeb0 net/core/fib_rules.c:321
Read of size 8 at addr ffff88804ec4c680 by task kworker/u8:21/12641

CPU: 0 UID: 0 PID: 12641 Comm: kworker/u8:21 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 fib_rules_lookup+0x15e/0xeb0 net/core/fib_rules.c:321
 __fib_lookup+0x106/0x210 net/ipv4/fib_rules.c:96
 ip_route_output_key_hash_rcu+0x294/0x2720 net/ipv4/route.c:2811
 ip_route_output_key_hash+0x18d/0x2a0 net/ipv4/route.c:2702
 __ip_route_output_key include/net/route.h:169 [inline]
 ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2929
 ip4_datagram_release_cb+0x89d/0xbe0 net/ipv4/datagram.c:118
 release_sock+0x206/0x260 net/core/sock.c:3861
 inet_shutdown+0x2b1/0x390 net/ipv4/af_inet.c:950
 udp_tunnel_sock_release+0x6d/0x80 net/ipv4/udp_tunnel_core.c:197
 fou_release net/ipv4/fou_core.c:562 [inline]
 fou_exit_net+0x17d/0x1f0 net/ipv4/fou_core.c:1230
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x43d/0x8d0 net/core/net_namespace.c:252
 cleanup_net+0x572/0x810 net/core/net_namespace.c:702
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Fixes: 759923cf03 ("ipv4: fib: Convert fib_net_exit_batch() to ->exit_rtnl().")
Reported-by: syzbot+965506b59a2de0b6905c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/6a315824.b0403584.28d0ff.0000.GAE@google.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260616191359.4142661-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 15:42:53 -07:00
Jakub Kicinski
d755d45bc0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge in late fixes in preparation for the net-next PR.

Conflicts:

net/tls/tls_sw.c
  406e8a651a ("net: skmsg: preserve sg.copy across SG transforms")
  79511603a6 ("tls: remove dead sockmap (psock) handling from the SW path")

drivers/net/ethernet/microsoft/mana/mana_en.c
  f8fd56977e ("net: mana: guard TX wq object destroy with INVALID_MANA_HANDLE check")
  d07efe5a6e ("net: mana: Use per-queue allocation for tx_qp to reduce allocation size")
https://lore.kernel.org/ajAPXu-C_PuTgV-a@sirena.org.uk

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-16 14:59:58 -07:00