Commit Graph

1463602 Commits

Author SHA1 Message Date
Joshua Hay
bef152db47 idpf: adjust TxQ ring count minimum
Set the TxQ ring count minimum to 128 descriptors. Any lower than this,
and the queue will stall and trigger Tx timeouts in flow based
scheduling mode. This is because next_to_clean might never be updated.

In flow based scheduling mode, next_to_clean is only updated after a
descriptor completion is processed, i.e. after the RE bit is set in the
last descriptor of a Tx packet. This will never happen with a ring size
of 64 and an IDPF_TX_SPLITQ_RE_MIN_GAP of 64. No matter what the value
of last_re is initialized/set to, the calculated gap will be at most 63
and never trigger the RE bit.

Even a ring size of 96 does not solve this. Because of how infrequent
next_to_clean is updated and how small the ring is, IDPF_DESC_UNUSED
will be much smaller on average. This increases the chance the queue
will be stopped because a multi-descriptor packet, e.g. a large LSO
packet, does not see enough resources on the ring. In this case, the
queue will trigger the stop logic. The queue permanently stalls because
there is no chance for a descriptor completion to update next_to_clean
since it is dependent on a packet being sent.

Fixes: 5f417d5513 ("idpf: replace flow scheduling buffer ring with buffer pool")
Signed-off-by: Joshua Hay <joshua.a.hay@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Tested-by: Samuel Salin <Samuel.salin@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
2026-07-28 11:23:01 -07:00
Michael Bommarito
9f7007ee98 idpf: bound interrupt-vector register fill to the allocated array
idpf_get_reg_intr_vecs() fills the caller-allocated reg_vals[] array from
the VIRTCHNL2_OP_ALLOC_VECTORS reply in adapter->req_vec_chunks, bounding
its inner loop only by the per-chunk num_vectors. The array is sized
separately: idpf_intr_reg_init() allocates
kzalloc_objs(struct idpf_vec_regs, total_vecs) from
caps.num_allocated_vectors and only checks the returned count after the
fill. The sum of per-chunk num_vectors is never reconciled against
total_vecs, so a reply with a small num_allocated_vectors but chunks
summing higher writes past the end of reg_vals[].

Impact: a control plane (a PF or hypervisor device model) that returns a
VIRTCHNL2_OP_ALLOC_VECTORS reply whose per-chunk num_vectors sum exceeds
num_allocated_vectors writes struct idpf_vec_regs entries past the end of
the reg_vals kmalloc allocation (KASAN slab-out-of-bounds write).

Bound the fill loop to the array capacity passed in by the callers,
mirroring the sibling idpf_vport_get_q_reg(). The existing
num_regs < num_vecs check then rejects an undersized reply without the
out-of-bounds write happening first.

Fixes: d4d5587182 ("idpf: initialize interrupts and enable vport")
Assisted-by: Claude:claude-opus-4-7
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Tested-by: Samuel Salin <Samuel.salin@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
2026-07-28 11:23:01 -07:00
Chenguang Zhao
e095f249e2 net: ethernet: mtk_eth_soc: pass eth to mtk_handle_irq_rx in poll_controller
mtk_handle_irq_rx expects a struct mtk_eth * (matching the request_irq
cookie), but mtk_poll_controller incorrectly passed the net_device *.
Calling ndo_poll_controller with CONFIG_NET_POLL_CONTROLLER enabled
would then crash.

Fixes: 8186f6e382 ("net-next: mediatek: fix compile error inside mtk_poll_controller()")
Signed-off-by: Chenguang Zhao <zhaochenguang@kylinos.cn>
Link: https://patch.msgid.link/20260723055735.885112-1-chenguang.zhao@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-28 15:53:49 +02:00
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
88c17de85d bpf: lwt: Fix dst reference leak on reroute failure
bpf_lwt_xmit_reroute() obtains a referenced dst from the route
lookup. When skb_cow_head() fails before that dst is installed on the
skb, the error path only frees the skb. The skb still owns its previous
dst, so the newly looked up dst reference is leaked.

Release the new dst reference before freeing the skb on this error
path.

Fixes: 3bd0b15281 ("bpf: add handling of BPF_LWT_REROUTE to lwt_bpf.c")
Cc: stable@vger.kernel.org
Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn>
Link: https://patch.msgid.link/20260723060445.21926-1-xuanqiang.luo@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-28 13:22:11 +02:00
Xuanqiang Luo
f621d6ebee net/smc: fix socket use-after-free during link group termination
__smc_lgr_terminate() drops conns_lock after finding a connection in
lgr->conns_all, but before taking a reference on its socket. The connection
is embedded in the socket, and its registration reference protects it only
while the connection remains in the tree.

A concurrent close can unregister the connection and drop that reference,
freeing the socket before the termination worker reaches sock_hold().

The race is reachable when close overlaps link group termination.
Local stress testing reproduced the use-after-free and KASAN reported:

  BUG: KASAN: slab-use-after-free in __smc_lgr_terminate.part.0 [smc]
  Write of size 4 by task kworker/3:3
  Workqueue: events smc_lgr_terminate_work [smc]
  __smc_lgr_terminate.part.0 [smc]

The socket was allocated by smc_create(), freed through
slab_free_after_rcu_debug(), and was followed by:

  refcount_t: addition on 0; use-after-free.
  __smc_lgr_terminate.part.0 [smc]

Take the socket reference while conns_lock still protects the tree entry.
The unregister path then cannot drop the last reference until termination
has finished using the socket.

Fixes: 69318b5215 ("net/smc: improve abnormal termination locking")
Cc: stable@vger.kernel.org
Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn>
Reviewed-by: Mahanta Jambigi <mjambigi@linux.ibm.com>
Link: https://patch.msgid.link/20260723105454.87016-1-xuanqiang.luo@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-28 11:22:43 +02:00
Cen Zhang (Microsoft)
aef96eead2 net/sched: cls_u32: validate offshift to prevent shift-out-of-bounds
u32_change() copies the user-provided tc_u32_sel.offshift (unsigned char,
0-255) into the kernel knode object without bounds validation. When a
packet later hits u32_classify() with TC_U32_VAROFFSET set, it evaluates
`ntohs(offmask & *data) >> offshift` where the left operand is a 16-bit
value promoted to a 32-bit int. Any offshift >= 32 is undefined behavior
per C11 6.5.7p3, triggerable by an unprivileged user via user/network
namespaces.

UBSAN: shift-out-of-bounds in net/sched/cls_u32.c:236:43
shift exponent 32 is too large for 32-bit type int

Fix this by rejecting offshift >= 16 during filter creation in
u32_change().

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: AutonomousCodeSecurity@microsoft.com
Link: https://lore.kernel.org/all/20260720034514.23053-1-blbllhy@gmail.com
Signed-off-by: Cen Zhang (Microsoft) <blbllhy@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Tested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Tested-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20260723044955.89471-1-blbllhy@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-28 11:18:58 +02:00
Yehyeong Lee
295dd295e2 net: mpls: initialize rtm_tos in mpls_getroute()
mpls_getroute() builds the RTM_NEWROUTE reply to an RTM_GETROUTE
request by filling a struct rtmsg allocated from an skb whose data
area is not zeroed (alloc_skb(NLMSG_GOODSIZE, ...)). It sets every
field of the header except rtm_tos:

	r = nlmsg_data(nlh);
	r->rtm_family	 = AF_MPLS;
	r->rtm_dst_len	= 20;
	r->rtm_src_len	= 0;
	r->rtm_table	= RT_TABLE_MAIN;
	r->rtm_type	= RTN_UNICAST;
	r->rtm_scope	= RT_SCOPE_UNIVERSE;
	r->rtm_protocol = rt->rt_protocol;
	r->rtm_flags	= 0;

struct rtmsg has no padding, so the one uninitialised byte rtm_tos
(offset 3) is copied straight to user space on recvmsg(), leaking a
byte of uninitialised heap memory. This is in contrast to
mpls_dump_route(), which fills the very same header and does set
rtm_tos = 0.

Initialize rtm_tos to 0, matching mpls_dump_route().

Reproduced with KMSAN by adding an MPLS route and issuing a
non-RTM_F_FIB_MATCH RTM_GETROUTE for its label:

  BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x36c/0x33f0
   _copy_to_iter+0x36c/0x33f0
   __skb_datagram_iter+0x196/0x12c0
   skb_copy_datagram_iter+0x5b/0x210
   netlink_recvmsg+0x37b/0xef0
   ...
  Uninit was created at:
   __alloc_skb+0x8ca/0x10e0
   mpls_getroute+0x1280/0x3a40
   rtnetlink_rcv_msg+0x1138/0x15a0
   ...
  Byte 19 of 64 is uninitialized

(byte 19 = nlmsghdr(16) + rtmsg offset 3 = rtm_tos)

Fixes: 397fc9e5ce ("mpls: route get support")
Signed-off-by: Yehyeong Lee <yhlee@isslab.korea.ac.kr>
Link: https://patch.msgid.link/20260723010830.289917-1-yhlee@isslab.korea.ac.kr
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-28 11:06:06 +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 Joyner
97ac08560d ethtool: Embed FEC hist ranges as buffer in struct
When a driver's .get_fec_stats() handler is called and the driver
supports FEC histogram stats, the driver supplies the histogram bin
ranges via a pointer.  This pointer is assigned while under the netdev
ops lock in fec_prepare_data(), but the actual data is only read after
the lock is released; so this allows the driver to change the ranges
(e.g. from another .get_fec_stats() call) while the current call chain
is reading them in fec_fill_reply().

Fix this by adding an ethtool core-owned buffer, ranges_buf, to struct
ethtool_fec_hist. Drivers whose ranges are built dynamically (currently
just mlx5) fill ranges_buf and then point the existing ranges pointer at
it, giving ethtool a consistent copy that stays valid after the netdev
ops lock is dropped and later in fec_fill_reply(). Drivers whose ranges
are compile-time constants (bnxt, netdevsim) are unaffected by the
potential race and keep setting the existing ranges pointer to their
constant array, without making copies.

Fixes: cc2f081299 ("ethtool: add FEC bins histogram report")
Signed-off-by: Eric Joyner <eric.joyner@amd.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20260723041342.39238-1-eric.joyner@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 18:23:07 -07:00
Yun Lu
6fb7b769d6 rtase: fix double free of multi-frag skb on DMA map failure
In rtase_start_xmit(), when the head buffer DMA mapping fails after
rtase_xmit_frags() has mapped all fragments, the error path clears
the fragment descriptors with rtase_tx_clear_range(), which frees
the skb through the last-frag slot and accounts tx_dropped. Control
then falls through to the common error label, which frees the same
skb a second time and counts it again.

Return right after clearing the fragments when the skb owns frags;
the no-frag case still drops through and frees the head skb once.

Fixes: d6e882b89f ("rtase: Implement .ndo_start_xmit function")
Signed-off-by: Yun Lu <luyun@kylinos.cn>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Justin Lai <justinlai0215@realtek.com>
Link: https://patch.msgid.link/20260721023836.6691-1-luyun_611@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 18:16:42 -07:00
Aswin Karuvally
d211028bac s390/qeth: Check CAP_NET_ADMIN for private ioctls
Gate the SIOCDEVPRIVATE ioctl commands SIOC_QETH_ADP_SET_SNMP_CONTROL,
SIOC_QETH_GET_CARD_TYPE and SIOC_QETH_QUERY_OAT with CAP_NET_ADMIN
capable check to ensure unprivileged users cannot invoke them.

Fixes: 18787eeebd ("qeth: use ndo_siocdevprivate")
Cc: stable@vger.kernel.org
Suggested-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Aswin Karuvally <aswin@linux.ibm.com>
Link: https://patch.msgid.link/20260723140050.762991-1-aswin@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 18:05:19 -07:00
Chenguang Zhao
22666ba142 forcedeth: fix UAF of txrx_stats in nv_remove
nv_remove() frees the per-CPU txrx_stats before unregister_netdev().
Until unregister completes, ndo_get_stats64, the NAPI/xmit data path,
and nv_close()/drain may still access txrx_stats, leading to a
use-after-free.

Free the stats only after unregister_netdev().

Fixes: f4b633b911 ("forcedeth: use per cpu to collect xmit/recv statistics")
Signed-off-by: Chenguang Zhao <zhaochenguang@kylinos.cn>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Link: https://patch.msgid.link/20260723092637.2135095-1-chenguang.zhao@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 17:52:50 -07:00
David Corvaglia
5546da8689 net: bridge: mrp: fix Option TLV length in MRP_Test frames
oui is a pointer, so sizeof(oui) is the pointer size. The MRA
Option TLV thus advertises a wrong length (15 vs 10 on x86_64),
causing misparsing of the frame on peers. Fix is to replace
with sizeof(*oui).

Fixes: f7458934b0 ("net: bridge: mrp: Update the Test frames for MRA")
Signed-off-by: David Corvaglia <david@corvaglia.dev>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260726062605.2746-1-david@corvaglia.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 15:56:55 -07:00
Asim Viladi Oglu Manizada
bd0e9289e2 sctp: prevent peer transport count overflow
sctp_assoc_add_peer() increments the association's 16-bit transport_count
for every new unique peer. Adding the 65,536th transport wraps the count to
zero.

SCTP sock_diag uses transport_count to reserve the INET_DIAG_PEERS payload,
then copies one sockaddr_storage for every entry in transport_addr_list.
After the wrap, a diagnostic dump reserves an empty payload and writes
8 MiB of peer addresses past the skb tail.

Reject a new unique peer when transport_count has reached U16_MAX. Perform
the check after the existing-peer lookup so a duplicate address continues
to return its existing transport at the limit.

Fixes: 8f840e47f1 ("sctp: add the sctp_diag.c file")
Cc: stable@vger.kernel.org
Signed-off-by: Asim Viladi Oglu Manizada <manizada@pm.me>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20260725032053.521705-1-manizada@pm.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 15:45:24 -07:00
Yuxiang Yang
9d8da8e0a9 sctp: reject stale cookies with mismatched verification tags
sctp_unpack_cookie() skips cookie expiration checks whenever an
association already exists.  This is broader than the exception in
RFC 9260 Section 5.2.4.

For an existing association, Section 5.2.4 permits an expired State
Cookie only when both Verification Tags in the cookie match the current
association.  Otherwise, the packet SHOULD be discarded and a Stale
Cookie ERROR MUST be sent.

The broad check lets an expired Action A restart cookie reach
sctp_sf_do_dupcook_a().  In a runtime test with the default 60 second
cookie lifetime, replaying such a cookie after 65 seconds returned a
COOKIE-ACK and restarted the association.

Check cookie expiration unless both Verification Tags match.  This
preserves the Action D exception for a lost COOKIE ACK while rejecting
expired cookies in all other cases.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20260723225623.2658868-1-yangyx22@mails.tsinghua.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 15:23:29 -07:00
Zhiling Zou
a39789f211 net: bridge: stop fast-leave after deleting a port group
br_multicast_leave_group() iterates mp->ports with pp = &p->next in
its fast-leave path. After br_multicast_del_pg() removes p,
continuing the loop advances pp through the deleted entry.

If multicast-to-unicast was enabled, the bridge can hold multiple port
groups for the same port and group with different source MAC
addresses. Once multicast-to-unicast is disabled,
br_port_group_equal() matches those entries by port only. A fast leave
can then delete one entry and continue from its stale next pointer,
leaving mp->ports pointing at a deleted port group.

Fast leave only needs to remove one matching port group. Break after
br_multicast_del_pg() so the loop stops before dereferencing the
removed entry.

Fixes: 6db6f0eae6 ("bridge: multicast to unicast")
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>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/1cf0898872ef7c72d5f4c0304414a192c6dac591.1784707712.git.zhilinz@nebusec.ai
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 15:20:27 -07:00
Zhiling Zou
6aea62e433 net: ipv6: clear suppressed fib6 rule result
fib6_rule_suppress() drops a suppressed route with ip6_rt_put_flags(),
but leaves res->rt6 pointing at the released rt6_info.

If no later rule supplies a replacement, fib6_rule_lookup() still sees
res.rt6 and returns that stale dst to its caller. A suppressing rule can
therefore leak a released route back to rt6_lookup(), and the next put
hits rcuref_put_slowpath() from dst_release().

Clear res->rt6 when suppressing the route so suppressed lookups fall
through to the null dst instead of reusing the released one.

Fixes: cdef485217 ("ipv6: fix memory leak in fib6_rule_suppress")
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>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/4b8acb7787d54e440155585dd32ebdf0bef7d122.1784710966.git.zhilinz@nebusec.ai
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 15:20:01 -07:00
Zihan Xi
b4f1719dfe tipc: avoid use-after-free in poll trace queue dumps
TIPC socket tracepoints dump queue state through tipc_sk_dump(). Most
queue-dump callsites already serialize that walk under the socket lock or
sk->sk_lock.slock, but tipc_poll() calls trace_tipc_sk_poll(...,
TIPC_DUMP_ALL, ...) without holding either lock.

That lets the poll trace path reach tipc_list_dump() and backlog head/tail
dumping while another context dequeues and frees an skb, leaving the trace
helper dereferencing a stale queue entry.

Stop the unlocked poll trace site from requesting queue dumps. Other queue
dump trace callsites keep their existing output under the locking they
already provide, while poll still emits the event itself without walking
live queue members from an unlocked context.

Fixes: b4b9771bcb ("tipc: enable tracepoints in tipc")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Signed-off-by: Zihan Xi <zihanx@nebusec.ai>
Signed-off-by: Ren Wei <enjou1224z@gmail.com>
Reviewed-by: Tung Nguyen <tung.quang.nguyen@est.tech>
Link: https://patch.msgid.link/f8119abd5e5ecc400597de667ae9d39656de56d0.1784794294.git.zihanx@nebusec.ai
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 15:18:59 -07:00
Jakub Kicinski
9c88929cc1 Merge branch 'vxlan-fixes-for-skb-header-pulling-cloning-and-concurrency-in-tx-path'
Eric Dumazet says:

====================
vxlan: fixes for skb header pulling, cloning, and concurrency in TX path

While working on RTNL-less fill_info for vxlan, Sashiko found annoying
pre-existing issues, adding noise to an already complex work.

This series addresses some of them in VXLAN transmit path,
primarily within route_shortcircuit(), header validation, and neighbour
lookup.

Patch 1 fixes a potential use-after-free in vxlan_xmit() caused by caching
the Ethernet header pointer ('eth') before calling route_shortcircuit(),
which can reallocate skb->head via pskb_may_pull().

Patch 2 calls skb_cow_head() in route_shortcircuit() before modifying the
Ethernet header in-place, preventing packet header corruption when the skb
is cloned (e.g., by packet sockets, tcpdump, or dev_queue_xmit).

Patch 3 replaces direct reads of n->ha in route_shortcircuit() with
neigh_ha_snapshot() to safely snapshot the neighbour hardware address
under seqlock protection, avoiding potential torn reads during
asynchronous updates.

Patch 4 changes route_shortcircuit() to use pskb_network_may_pull() instead
of pskb_may_pull(). Since skb->data points to the MAC header on transmit
(skb_network_offset(skb) == ETH_HLEN), pskb_may_pull() was only checking
6 bytes into the IP header, leaving the remainder un-pulled in non-linear
frags.

Patch 5 applies pskb_network_may_pull() to the remaining transmit-path
header pull checks in arp_reduce(), ND solicitation proxy checks, and
MDB entry lookup, where skb->data similarly points to the Ethernet header.
====================

Link: https://patch.msgid.link/20260723144249.759100-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 15:16:31 -07:00
Eric Dumazet
b9553558b4 vxlan: use pskb_network_may_pull() for transmit path header pulls
In vxlan_xmit(), arp_reduce(), and vxlan_mdb_entry_skb_get(), pskb_may_pull() was
being called to verify the availability of network layer headers (ARP, IPv6/ND,
IP/IPv6 MDB keys).

However, during transmit skb->data points to the MAC header, so skb_network_offset(skb)
is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, len) only checks len bytes from skb->data
rather than skb_network_offset(skb) + len, which can leave part of the network header
in non-linear frags.

Replace these remaining pskb_may_pull() calls with pskb_network_may_pull() to properly
account for the MAC header offset.

Fixes: e4f67addf1 ("add DOVE extensions for VXLAN")
Fixes: f564f45c45 ("vxlan: add ipv6 proxy support")
Fixes: 0f83e69f44 ("vxlan: Add MDB data path support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260723144249.759100-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 15:16:15 -07:00
Eric Dumazet
26bb2dd0a8 vxlan: use pskb_network_may_pull() in route_shortcircuit()
route_shortcircuit() currently calls pskb_may_pull(skb, sizeof(struct iphdr))
(or ipv6hdr), which checks if bytes are available starting from skb->data.

However, in vxlan_xmit(), skb->data points to the MAC header, so
skb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, 20)
only checks 20 bytes from skb->data (which is 14 bytes MAC header + 6 bytes of
IP header), leaving the rest of the IP header potentially un-pulled in non-linear
frags. Subsequent dereferences of ip_hdr(skb)->daddr can read beyond the pulled
linear buffer length.

Fix this by using pskb_network_may_pull(), which adds skb_network_offset(skb) to
the length check to ensure the full network header is present in the linear buffer.

Fixes: e4f67addf1 ("add DOVE extensions for VXLAN")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20260723144249.759100-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 15:15:13 -07:00
Eric Dumazet
8eca411347 vxlan: use neigh_ha_snapshot() in route_shortcircuit()
The neighbour hardware address n->ha can be updated asynchronously by the
neighbour subsystem, protected by n->ha_lock seqlock. Reading n->ha without
holding the seqlock loop can lead to torn reads or reading a partially updated
MAC address.

Use neigh_ha_snapshot() in route_shortcircuit() to safely copy n->ha under
read_seqbegin()/read_seqretry() lock protection before using it.

Note that arp_reduce() and neigh_reduce() seem to have the same issue
left for future patches.

Fixes: e4f67addf1 ("add DOVE extensions for VXLAN")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20260723144249.759100-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 15:15:13 -07:00
Eric Dumazet
760d36e737 vxlan: unclone skb head before modifying eth header in route_shortcircuit()
When route_shortcircuit() performs L3 short-circuit routing, it modifies
the Ethernet header of the skb in-place:
    memcpy(eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, dev->addr_len);
    memcpy(eth_hdr(skb)->h_dest, n->ha, dev->addr_len);

If the incoming skb is cloned (for example by packet sockets, tcpdump, or
dev_queue_xmit), modifying the Ethernet header without uncloning can corrupt
the packet header for other readers holding a reference to the cloned skb.

Ensure the skb header is writable and unshared by calling skb_cow_head(skb, 0)
prior to updating the Ethernet header. If skb_cow_head() fails, abort short-circuiting
and return false to allow standard packet processing fallback.

Fixes: e4f67addf1 ("add DOVE extensions for VXLAN")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260723144249.759100-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 15:15:13 -07:00
Eric Dumazet
1395a676ec vxlan: re-fetch eth header after route_shortcircuit()
Before route_shortcircuit(), the eth header pointer is cached from eth_hdr(skb).

Inside route_shortcircuit(), pskb_may_pull() can be called, which may
reallocate skb->head.

In this case, returning to vxlan_xmit() leaves the cached eth pointer pointing to
freed memory, leading to a use-after-free when dereferencing eth->h_dest.

Fix this by updating eth = eth_hdr(skb) after calling route_shortcircuit().

Fixes: ae88408256 ("VXLAN: Allow L2 redirection with L3 switching")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20260723144249.759100-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27 15:15:13 -07:00
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
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
Matt Fleming
d0d6415963 veth: convert frag_list skbs before running XDP
A frag_list skb can reach veth with data_len set but nr_frags zero.
veth_convert_skb_to_xdp_buff() only converts skbs that are shared,
locked, have frags[], or do not have enough headroom. It later uses
skb_is_nonlinear() to decide whether to set XDP_FLAGS_HAS_FRAGS and
xdp_frags_size.

That exposes frag_list data to XDP as if it were stored in frags[], but
frags[] is empty. AF_XDP copy mode can then trust the bogus XDP fragment
metadata, walk an empty fragment entry, and crash in memcpy() from
__xsk_rcv().

Route non-linear skbs through skb_pp_cow_data() before exposing them to
XDP, and only advertise XDP frags when the resulting skb has frags[].
skb_copy_bits() already handles frag_list input, and skb_pp_cow_data()
builds frags[] output with skb_add_rx_frag(), which is the
representation XDP multi-buffer expects.

Fixes: 718a18a0c8 ("veth: Rework veth_xdp_rcv_skb in order to accept non-linear skb")
Cc: stable@vger.kernel.org
Signed-off-by: Matt Fleming <mfleming@cloudflare.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@toke.dk>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260722191925.2192070-1-matt@readmodwrite.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 17:02:10 -07:00
Chengfeng Ye
817ff6efdb net: pktgen: fix proc entry use-after-free
pktgen_change_name() replaces pkt_dev->entry while holding t->if_lock.
pktgen_remove_device() removes the same entry before
_rem_dev_from_if_list() takes that lock.

This allows the following interleaving:

  CPU 0 (NETDEV_CHANGENAME)       CPU 1 (kpktgend)
  if_lock(t)
  proc_remove(pkt_dev->entry)
                                  proc_remove(pkt_dev->entry)
  pkt_dev->entry = proc_create_data(...)
  if_unlock(t)

The kthread can pass the stale proc_dir_entry to proc_remove() after the
rename path has freed it. A reproducer with a widened race window reports:

  BUG: KASAN: slab-use-after-free in proc_remove+0x78/0x80
  Read of size 8 at addr ffff8881478fea70 by task kpktgend_0/67
  Call Trace:
   proc_remove+0x78/0x80
   pktgen_remove_device.isra.0+0x11c/0x4c0
   pktgen_thread_worker+0x1214/0x6bc0
   kthread+0x2c6/0x3b0
  Allocated by task 95:
   __proc_create+0x204/0x790
   proc_create_data+0x72/0xe0
   pktgen_thread_write+0xd61/0x1510
  Freed by task 28:
   kmem_cache_free+0xcb/0x3d0
   proc_free_inode+0x5b/0x80
   rcu_core+0x50a/0x1850
  The buggy address belongs to the object at ffff8881478fea00
   which belongs to the cache proc_dir_entry of size 192

Move proc_remove() into the if_lock-protected list removal helper. Keep it
before list_del_rcu() to preserve the ordering required by add_device().
The rename path must then finish replacing the entry before removal, or
it observes that the device is no longer on the list.

Fixes: 39df232f1a ("[PKTGEN]: fix device name handling")
Cc: stable@vger.kernel.org
Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260719145740.2888967-1-nicoyip.dev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 16:29:20 -07:00
Jonas Köppeler
a3729e0df0 net/sched: sch_cake: skip clearing unused tins during rate adjustment
When cake_configure_rates() is called from the dequeue path with
rate_adjust=true, it only needs to update the rate parameters. The
loop that clears the unused tins is both unnecessary and harmful in
this path:

 - cake_clear_tin() overwrites q->cur_tin and q->cur_flow, which are
   actively used by cake_dequeue(), corrupting the dequeue state.
 - iterating over the unused tins and their internal queues to purge
   packets adds needless overhead to the hot path.

Skip the entire loop when rate_adjust is set, as neither
cake_clear_tin() nor the mtu_time update are needed when only the
rate changes.

The clearing loop runs on every rate adjustment from the dequeue path,
clearing (max_tins - cur_tins) tins each time, so the cost grows the
fewer tins the configured mode actually uses. Testing cake_mq over veth
(8 rx/tx queues, 2 Gbit limit) with flent's [1] rrul and tcp_nup tests and
32 TCP upstreams shows a large drop in loaded latency and a throughput
gain, restoring behaviour to pre-15c2715a5264 levels:

  +------------+------+------+-------+-------+---------+
  | kernel     | mode | test |  base |  load |    tput |
  |            |      |      |  (ms) |  (ms) |  (Mbit) |
  +------------+------+------+-------+-------+---------+
  | net-next   | be   | rrul | 0.810 | 11.78 | 1469.67 |
  | net-next   | be   | nup  | 0.637 | 85.71 | 1243.15 |
  | net-next   | ds3  | rrul | 0.397 | 15.28 | 1770.06 |
  | net-next   | ds3  | nup  | 0.351 | 15.98 | 1799.39 |
  +------------+------+------+-------+-------+---------+
  | patched    | be   | rrul | 0.092 |  0.56 | 1873.40 |
  | patched    | be   | nup  | 0.109 |  1.82 | 1869.12 |
  | patched    | ds3  | rrul | 0.097 |  0.98 | 1866.10 |
  | patched    | ds3  | nup  | 0.101 |  0.51 | 1861.79 |
  +------------+------+------+-------+-------+---------+

The same trend holds on real hardware (IPQ8074A, 4 rx/tx queues,
OpenWrt): in besteffort mode the tcp_nup loaded latency drops from
~470 ms to ~4 ms.

[1] https://flent.org

Fixes: 15c2715a52 ("net/sched: sch_cake: fixup cake_mq rate adjustment for diffserv config")
Signed-off-by: Jonas Köppeler <j.koeppeler@tu-berlin.de>
Tested-by: Mike Pham <mikepham4321@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://patch.msgid.link/20260720-sch_cake-skip-clearing-tins-v2-1-e6a8b0275c73@tu-berlin.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 16:26:51 -07:00
Ivan Vecera
2c1bd78dc8 dpll: use pin owner's dpll ref for pin-level attribute reporting
Commit c191b319f2 ("dpll: allow registering FW-identified pin with a
different DPLL") relaxed dpll_pin_register() to let fwnode-identified pins
register with DPLLs from a different driver. This allows, for example, the
ICE driver to register a zl3073x-created pin with its TXC DPLL using
ice_dpll_txclk_ops, which lack frequency_get and phase_adjust_get
callbacks.

After such cross-driver registration, the pin's dpll_refs xarray contains
refs from both drivers. dpll_cmd_pin_get_one() calls
dpll_xa_ref_dpll_first() which returns the ref with the lowest DPLL id.
When the foreign DPLL (e.g. ICE TXC) has a lower id than the owner DPLL
(e.g. zl3073x), the foreign ops are used for reporting. Since those ops
lack callbacks like frequency_get, pin-level attributes are silently
omitted from the netlink response.

For example, a zl3073x output pin that should report frequency and
phase-adjust shows neither:

Before:
  # dpll pin show id 45
  pin id 45:
    module-name: zl3073x
    clock-id: 3427468959636104019
    board-label: 156M25_NAC0_CLKREF_SYNC
    package-label: OUT3
    type: synce-eth-port
    capabilities: 0x0
    phase-adjust-min: -2147483648
    phase-adjust-max: 2147483647
    phase-adjust-gran: 800
    parent-device:
      ...

After:
  # dpll pin show id 19
  pin id 19:
    module-name: zl3073x
    clock-id: 15964355450360090479
    board-label: 156M25_NAC0_CLKREF_SYNC
    package-label: OUT3
    type: synce-eth-port
    frequency: 156250000 Hz
    frequency-supported:
      156250000 Hz
    capabilities: 0x0
    phase-adjust-min: -2147483648
    phase-adjust-max: 2147483647
    phase-adjust-gran: 800
    phase-adjust: 0
    parent-device:
      ...

Fix this by:

1. Adding dpll_pin_own_dpll_ref_first() helper that returns the first ref
   whose DPLL matches the pin's (module, clock_id) tuple -- i.e. the DPLL
   from the driver that created the pin and has the complete set of ops.
   Return NULL if no owner ref is found.

2. Using dpll_pin_own_dpll_ref_first() in dpll_cmd_pin_get_one() with a
   fallback to dpll_xa_ref_dpll_first() for pin-on-pin child pins whose
   dpll_refs all point to a different driver's DPLLs.

3. Using dpll_pin_own_dpll_ref_first() in SET operations
   (dpll_pin_freq_set, dpll_pin_esync_set, dpll_pin_ref_sync_state_set,
   dpll_pin_phase_adj_set) returning -ENODEV if no owner ref exists.
   Replacing the validation loops that rejected the entire operation when
   any ref's ops lacked the required callback -- instead validate only the
   owner refs so that foreign DPLLs with incomplete ops no longer block
   SET operations.

4. Guarding all SET and rollback xa_for_each loops against NULL set
   callbacks so that foreign refs without the operation are safely skipped
   instead of causing a NULL pointer dereference.

Fixes: c191b319f2 ("dpll: allow registering FW-identified pin with a different DPLL")
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Acked-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20260714125945.1823269-1-ivecera@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 16:15:19 -07:00
Jakub Kicinski
c7b0c91259 Merge branch 'xsk-fix-af_xdp-multi-buffer-tx-descriptor-reclaim'
Maciej Fijalkowski says:

====================
xsk: fix AF_XDP multi-buffer Tx descriptor reclaim

This series fixes several AF_XDP multi-buffer Tx paths where descriptors
consumed from the Tx ring are not consistently returned to userspace
through the completion ring when the packet is later dropped as invalid.

The affected cases are invalid or oversized multi-buffer Tx packets in
both the generic and zero-copy paths. In these cases, the kernel can
consume one or more Tx descriptors while building or validating a
multi-buffer packet, then drop the packet before it reaches the device.
Userspace still owns the UMEM buffers only after the corresponding
addresses are returned through the CQ. Missing completions therefore
make userspace lose track of those buffers.

The generic path fixes cover following related cases:
* partially built multi-buffer skbs dropped by xsk_drop_skb();
  continuation descriptors left in the Tx ring after xsk_build_skb()
  reports overflow;
* invalid descriptors encountered in the middle of a multi-buffer
  packet, including the offending invalid descriptor itself.

The zero-copy path is handled separately. The batched Tx parser now
distinguishes descriptors that can be passed to the driver from
descriptors that are consumed only because they belong to an invalid
multi-buffer packet. Reclaim-only descriptors are written to the CQ
address area and published in completion order, after any earlier
driver-visible Tx descriptors.

The last two patches update xskxceiver so the tests account invalid
multi-buffer Tx packets as descriptors that must be reclaimed, while
still not expecting those invalid packets on the Rx side.

This is a follow-up to Jason's changes [0] which were addressing generic
xmit only and this set allows me to pass full xskxceiver test suite run
against ice driver.
====================

Link: https://patch.msgid.link/20260719135609.147823-1-maciej.fijalkowski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 15:12:17 -07:00
Maciej Fijalkowski
f49d99eaee selftests/xsk: account reclaimed invalid Tx descriptors
Invalid Tx descriptors are now returned through the completion ring,
regardless of whether they form a standalone packet or belong to an
invalid multi-buffer packet.

The selftests previously counted only descriptors belonging to valid
packets, with a special exception for some invalid multi-buffer packets
in verbatim streams. This undercounts completion entries when a
standalone invalid descriptor or another invalid packet is reclaimed by
the kernel.

Keep valid_pkts as the number of packets expected on the Rx side, but
count every descriptor submitted to the Tx ring in valid_frags, as every
such descriptor is now expected to be returned through the completion
ring.

Make fragment counting in verbatim mode follow the packet boundary
instead of stopping at the first invalid fragment. Update custom stream
generation so an invalid middle fragment terminates the generated Rx
packet while Tx completion accounting still covers the complete invalid
packet.

Also add explicit end fragments after invalid middle descriptors. This
exercises the kernel drain logic and verifies that subsequent valid
packets are not interpreted as continuations of the invalid packet.

Reviewed-by: Jason Xing <kernelxing@tencent.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260719135609.147823-7-maciej.fijalkowski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 15:12:15 -07:00
Maciej Fijalkowski
c5b1ca6a02 selftests/xsk: fix too-many-frags multi-buffer Tx test
The too-many-frags test describes a packet that is valid from the Tx
ring ownership point of view, but invalid for transmission because it
exceeds the supported number of fragments.

Keep the generated Tx descriptors valid so that __send_pkts() accounts
them as outstanding descriptors that must be reclaimed through the CQ.
Then mark the corresponding Rx packet invalid so the test still does
not expect the oversized packet to appear on the receive side.

Add a valid synchronization packet after the oversized packet so the
test can verify that the Tx path drains the bad packet and resumes at
the next packet boundary.

Reviewed-by: Jason Xing <kernelxing@tencent.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260719135609.147823-6-maciej.fijalkowski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 15:12:14 -07:00
Maciej Fijalkowski
72f2b4516f xsk: reclaim invalid Tx descriptors in ZC batch path
The zero-copy Tx batch parser stops when it encounters an invalid
descriptor. If this happens after one or more continuation descriptors,
the Tx consumer can be advanced past fragments that are neither submitted
to the driver nor returned to userspace through the completion ring.

A similar problem occurs when a packet exceeds xdp_zc_max_segs. The
descriptors consumed up to the limit are released without completion, and
the remaining continuation descriptors can subsequently be interpreted
as the beginning of another packet.

Parse Tx batches in packet units and distinguish descriptors belonging to
complete valid packets from descriptors consumed while draining an
invalid or oversized packet. Return the former to the driver and append
the latter to the CQ address area so userspace can reclaim their UMEM
frames.

Treat a standalone invalid descriptor as a one-descriptor reclaim-only
packet. Advancing the Tx-ring consumer releases the ring slot, but does
not by itself return ownership of the referenced UMEM frame to userspace.

Once draining starts, continue until the packet's end-of-packet
descriptor is consumed. Preserve the drain state on the socket when EOP
has not yet been supplied, so draining can continue during a later call.
Leave incomplete but otherwise valid packets on the Tx ring.

Shared-UMEM pools using multi-buffer Tx also need packet-framed parsing.
Walk their Tx sockets one packet at a time, preserving the existing
per-socket fairness scheme, instead of using the legacy one-descriptor
fallback. Keep that fallback for shared pools that do not use
multi-buffer Tx. Since the drain state is maintained per socket and both
the singular and shared paths can resume an interrupted drain, changing
the socket list from singular to shared requires no special bind-time
transition.

CQ entries are positional, and drivers may complete only part of the Tx
work returned by xsk_tx_peek_release_desc_batch(). Therefore, reclaim-only
entries cannot be published immediately when earlier driver-visible
descriptors are still outstanding.

Track the number of driver-visible CQ entries preceding the reclaim
entries. Let xsk_tx_completed() publish partial hardware Tx completions,
and publish the reclaim entries only after every earlier Tx descriptor
has completed. Complete a reclaim-only batch immediately when there is no
driver-visible work in front of it, and prevent another Tx batch from
being appended while reclaim entries remain pending.

Also cap batch processing by the size of the pool's temporary descriptor
array, as Tx rings belonging to sockets sharing a UMEM may have different
sizes.

This ensures that every invalid Tx descriptor consumed by the ZC batch
path is either submitted to the driver as part of a valid packet or
returned to userspace without violating CQ completion ordering.

Reviewed-by: Jason Xing <kernelxing@tencent.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Fixes: cf24f5a5fe ("xsk: add support for AF_XDP multi-buffer on Tx path")
Link: https://patch.msgid.link/20260719135609.147823-5-maciej.fijalkowski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 15:12:14 -07:00
Maciej Fijalkowski
08c9a8e794 xsk: provide sufficient space in pool->tx_descs
The temporary Tx descriptor array in an XSK buffer pool is currently
sized from the Tx ring of the socket that creates the pool.

This is insufficient for shared-UMEM Tx. A later socket may have a
larger Tx ring and submit a valid multi-buffer packet containing more
descriptors than the first socket's ring, while still remaining within
the device's xdp_zc_max_segs limit.

A packet-framed batch parser bounded by the temporary array cannot reach
the end-of-packet descriptor in that case. It leaves the packet on the
Tx ring and encounters the same packet on every subsequent attempt,
stalling Tx processing for that socket.

Size the temporary descriptor array to the larger of the first Tx ring
and the device's xdp_zc_max_segs capability. This keeps the array large
enough to inspect one maximum-sized valid packet. Larger shared Tx rings
do not require further resizing, as they can be processed over multiple
batches.

Following commit will actually address the data path side.

Fixes: d558196604 ("xsk: support ZC Tx multi-buffer in batch API")
Reviewed-by: Jason Xing <kernelxing@tencent.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260719135609.147823-4-maciej.fijalkowski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 15:12:14 -07:00
Jason Xing
bd44a6dcd4 xsk: drain continuation descs after overflow in xsk_build_skb()
Fix generic xmit path multi-buffer logic when packets are either too big
(count of descriptors exceed MAX_SKB_FRAGS) or an invalid descriptor is
included in fragmented packet. Introduce xdp_sock::drain_cont and act
upon this flag - when it is set, keep on consuming descriptors from
AF_XDP Tx ring and put them directly onto Cq. Previously these
descriptors were silently lost and could never be reached again.

Fixes: cf24f5a5fe ("xsk: add support for AF_XDP multi-buffer on Tx path")
Closes: https://lore.kernel.org/all/20260425041726.85FB3C2BCB2@smtp.kernel.org/
Reviewed-by: Jason Xing <kernelxing@tencent.com>
Co-developed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> # wrapped cq addr submission onto routine
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260719135609.147823-3-maciej.fijalkowski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 15:12:14 -07:00
Jason Xing
a3c8382ebc xsk: fix buffer leak in xsk_drop_skb() for AF_XDP multi-buffer Tx
This patch is inspired by the check[1] from sashiko. It says when
overflow happens, the address of cq to be published is invalid.
Actually the severer thing is the whole process of publishing the
address of cq in this particular case is not right: it should truely
publish the address and advance the cached_prod in cq as long as it
reads descriptors from txq.

The following is the full analysis.
xsk_drop_skb() is called in three places, which all discard a partially
built multi-buffer skb:
1) xsk_build_skb() -EOVERFLOW error path: packet exceeds MAX_SKB_FRAGS
2) __xsk_generic_xmit() post-loop cleanup: an invalid descriptor in
   the TX ring prevents the partial packet from completing
3) xsk_release(): socket close while xs->skb holds an incomplete packet

In all three cases, the TX descriptors for the already-processed frags
have been consumed from the TX ring (xskq_cons_release), and CQ slots
have been reserved. However, xsk_drop_skb() calls xsk_consume_skb()
which cancels the CQ reservations via xsk_cq_cancel_locked(). Since
the buffer addresses never appear in the completion queue, userspace
permanently loses track of these buffers.

Fix this by letting consume_skb() trigger the existing xsk_destruct_skb
destructor, which already submits buffer addresses to the CQ via
xsk_cq_submit_addr_locked().

Note that cancelling the descriptors back to the TX ring (via
xskq_cons_cancel_n) is not a appropriate option because an oversized
packet that always exceeds MAX_SKB_FRAGS would be retried indefinitely,
which is an obviously deadlock bug in the TX path.

Also move the desc->addr assignment in xsk_build_skb() above the
overflow check so that the current descriptor's address is recorded
before a potential -EOVERFLOW jump to free_err, consistent with the
zerocopy path in xsk_build_skb_zerocopy().

[1]: https://lore.kernel.org/all/20260425041726.85FB3C2BCB2@smtp.kernel.org/

Fixes: cf24f5a5fe ("xsk: add support for AF_XDP multi-buffer on Tx path")
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260719135609.147823-2-maciej.fijalkowski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 15:12:14 -07:00
John Ericson
7f57c650d0 selftests/net/af_unix: test listen() rejects wrong socket states
Add a regression test for the unix_listen() state check. The key case is
listen() on a bound socket that has already been connected: it is no
longer in TCP_CLOSE or TCP_LISTEN, so it must fail with EINVAL. A
prepare_peercred() call slipped in ahead of that check once left err at 0
and made listen() silently succeed there instead; this guards against a
repeat.

The neighbouring outcomes are covered too so they cannot regress the same
way: a bound socket in TCP_CLOSE listens fine, calling listen() again on a
socket already in TCP_LISTEN is allowed, and an unbound socket fails with
EINVAL.

Each case runs for both listenable socket types (SOCK_STREAM and
SOCK_SEQPACKET) and both pathname and abstract addresses.

Fixes: fd0a109a0f ("net, pidfs: prepare for handing out pidfds for reaped sk->sk_peer_pid")
Signed-off-by: John Ericson <mail@johnericson.me>
Link: https://patch.msgid.link/20260718182903.2295560-2-John.Ericson@Obsidian.Systems
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 15:10:05 -07:00
John Ericson
f0d9c3ffc2 af_unix: fix listen() succeeding on sockets in the wrong state
Commit fd0a109a0f ("net, pidfs: prepare for handing out pidfds for
reaped sk->sk_peer_pid") inserted a prepare_peercred() call between err
= -EINVAL and the socket-state check in unix_listen(). Since
prepare_peercred() leaves err at 0 on success, listen() on an AF_UNIX
socket that is not in TCP_CLOSE or TCP_LISTEN state (e.g. one that is
already connected) now silently returns success without doing anything,
instead of failing with EINVAL as it did before.

Fixes: fd0a109a0f ("net, pidfs: prepare for handing out pidfds for reaped sk->sk_peer_pid")
Signed-off-by: John Ericson <mail@johnericson.me>
Link: https://patch.msgid.link/20260718182903.2295560-1-John.Ericson@Obsidian.Systems
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 15:10:05 -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
Wenjia Zhang
9736d2efc9 MAINTAINERS: Update SHARED MEMORY COMMUNICATIONS (SMC) maintainer entries
Due to a change in responsibilities, I can no longer serve as an SMC
maintainer and need to be removed from the MAINTAINERS list.

To reflect these organizational changes, promote Mahanta Jambigi
<mjambigi@linux.ibm.com> from reviewer to maintainer.

Acked-by: Mahanta Jambigi <mjambigi@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Sidraya Jayagond <sidraya@linux.ibm.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Link: https://patch.msgid.link/20260724053752.3084-1-wenjia@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-24 14:45:44 -07:00
Xiang Mei
78f75d632f rds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check()
rds_tcp_laddr_check() looks up a scoped IPv6 interface with
dev_get_by_index_rcu(), drops the RCU read-side lock, and only then
passes the bare struct net_device * into ipv6_chk_addr().

dev_get_by_index_rcu() only keeps the device alive within the same RCU
read-side section. After rcu_read_unlock(), a concurrent RTM_DELLINK can
free the net_device; ipv6_chk_addr() then dereferences the stale pointer
in __ipv6_chk_addr_and_flags() (e.g. l3mdev_master_dev_rcu(dev)), reading
freed memory.

Keep the RCU read-side lock held across the ipv6_chk_addr() call instead
of dropping it right after the lookup, so the device cannot be freed
while it is in use.

  BUG: KASAN: slab-use-after-free in __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998)
  Read of size 8 at addr ffff8880106ec000 by task exploit/153
  Call Trace:
   ...
   kasan_report (mm/kasan/report.c:595)
   __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998)
   ipv6_chk_addr (net/ipv6/addrconf.c:2031 net/ipv6/addrconf.c:1972)
   rds_tcp_laddr_check (net/rds/tcp.c:370)
   rds_bind (net/rds/bind.c:248)
   __sys_bind (net/socket.c:1920)
   __x64_sys_bind (net/socket.c:1956)
   do_syscall_64 (arch/x86/entry/syscall_64.c:63)
   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)

Fixes: eee2fa6ab3 ("rds: Changing IP address internal representation to struct in6_addr")
Reported-by: Weiming Shi <bestswngs@gmail.com>
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Reviewed-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260722210203.565803-1-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23 14:11:37 -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
Jakub Kicinski
6a8da869fa Merge branch 'drop_monitor-take-care-of-32bit-kernels'
Eric Dumazet says:

====================
drop_monitor: take care of 32bit kernels

This series fixes two drop_monitor issues on 32-bit architectures:

- Patch 1 uses nla_total_size_64bit() for PC and TIMESTAMP attributes to
  account for alignment padding added by nla_put_u64_64bit(), avoiding
  potential skb_over_panic() crashes.

- Patch 2 moves u64_stats updates before spin_unlock_irqrestore(), ensuring
  local interrupts are disabled to prevent seqcount corruption from nested
  interrupts in probe context.
====================

Link: https://patch.msgid.link/20260722141743.3266924-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23 11:00:03 -07:00
Eric Dumazet
fd098a23bf drop_monitor: perform u64_stats updates under IRQ-disabled section
In net_dm_packet_trace_kfree_skb_hit() and net_dm_hw_trap_packet_probe(),
u64_stats_update_begin() / u64_stats_inc() / u64_stats_update_end() were
called after spin_unlock_irqrestore(&...drop_queue.lock, flags), when local
IRQs had already been re-enabled.

Tracepoint probes can execute in IRQ or softirq context. On 32-bit
architectures, u64_stats_update_begin() disables preemption but not interrupts,
relying on seqcount writes. If a nested interrupt occurs on the same CPU during
the 64-bit stats update, the reentrant seqcount update can corrupt the
seqcount state or stats value.

Fix this by performing the 64-bit per-CPU stats update before releasing
drop_queue.lock via spin_unlock_irqrestore(), ensuring local interrupts remain
disabled during the u64_stats update.

Fixes: e9feb58020 ("drop_monitor: Expose tail drop counter")
Fixes: 5e58109b1e ("drop_monitor: Add support for packet alert mode for hardware drops")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260722141743.3266924-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23 11:00:01 -07:00
Eric Dumazet
7089f7ab99 drop_monitor: fix size calculations for 64-bit attributes
net_dm_packet_report_fill() and net_dm_hw_packet_report_fill() use
nla_put_u64_64bit() to append 64-bit attributes (NET_DM_ATTR_PC and
NET_DM_ATTR_TIMESTAMP).

On 32-bit architectures without CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS,
nla_put_u64_64bit() may append a 4-byte NET_DM_ATTR_PAD attribute for
64-bit alignment.

However, net_dm_packet_report_size() and net_dm_hw_packet_report_size()
used nla_total_size(sizeof(u64)) instead of nla_total_size_64bit(sizeof(u64)),
budgeting 12 bytes instead of up to 16 bytes.

This under-estimation of SKB size can lead to an skb_over_panic() when
__nla_reserve() or skb_put() is subsequently called.

Fix this by using nla_total_size_64bit(sizeof(u64)) in both size calculations.

Fixes: ca30707dee ("drop_monitor: Add packet alert mode")
Fixes: 5e58109b1e ("drop_monitor: Add support for packet alert mode for hardware drops")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260722141743.3266924-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23 11:00:01 -07:00
Yehyeong Lee
5e9c8baee0 net: drop_monitor: fix info leak in NET_DM_ATTR_PAYLOAD
net_dm_packet_report_fill() and net_dm_hw_packet_report_fill() open code
the NET_DM_ATTR_PAYLOAD attribute to avoid zeroing the packet payload
before overwriting it with skb_copy_bits().

skb_put() reserves nla_total_size(payload_len), i.e. the header plus the
NLA_ALIGN() padding, but only payload_len bytes are copied in. When
payload_len is not a multiple of 4 the 1-3 padding bytes are never
initialized and are leaked to user space inside the netlink message.

KMSAN confirms the leak for the software path when the packet payload
length is not 4-byte aligned:

  BUG: KMSAN: kernel-infoleak in _copy_to_iter
   _copy_to_iter
   __skb_datagram_iter
   skb_copy_datagram_iter
   netlink_recvmsg
   sock_recvmsg
   __sys_recvfrom
  Uninit was created at:
   kmem_cache_alloc_node_noprof
   __alloc_skb
   net_dm_packet_work
  Bytes 173-175 of 176 are uninitialized

Use __nla_reserve(), which sets up the attribute header and zeroes the
padding, instead of open coding the attribute construction.

Fixes: ca30707dee ("drop_monitor: Add packet alert mode")
Fixes: 5e58109b1e ("drop_monitor: Add support for packet alert mode for hardware drops")
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yehyeong Lee <yhlee@isslab.korea.ac.kr>
Link: https://patch.msgid.link/20260722122817.5548-1-yhlee@isslab.korea.ac.kr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23 10:59:27 -07:00
Jakub Kicinski
1d4da823b7 Merge branch 'mptcp-misc-fixes-for-v7-2-rc5'
Matthieu Baerts says:

====================
mptcp: misc fixes for v7.2-rc5

Here are various unrelated fixes:

- Patch 1: decrement extra subflows counter in case of errors with
  passive MP_JOIN. A fix for v5.7.

- Patch 2: fix use-after-free in userspace_pm_get_local_id. A fix for
  v5.19.

- Patch 3: fix stale skb->sk reference on subflow close, in case of
  concurrent read operation. A fix for v6.19.

- Patch 4: wait on the correct port in the userspace_pm.sh selftest. A
  fix for v6.19.

- Patch 5: fix a BUILD_BUG_ON on legacy ARM config. A fix for v7.1.
====================

Link: https://patch.msgid.link/20260722-net-mptcp-misc-fixes-7-2-rc5-v1-0-6fb595bc86ef@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23 10:50:43 -07:00