Commit Graph

13615 Commits

Author SHA1 Message Date
Kuniyuki Iwashima
759923cf03 ipv4: fib: Convert fib_net_exit_batch() to ->exit_rtnl().
Currently, IPv4 routes are flushed in ->exit_batch() after
all devices are unregistered.

Unlike IPv6, IPv4 routes are not added from the fast path,
so we can flush routes before default_device_exit_batch().

Let's call ip_fib_net_exit() from ->exit_rtnl() to save
one RTNL locking dance.

ip_fib_net_exit() must use list_del_rcu() for fib_table
for the fast path on dying dev.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260612063225.455191-6-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 11:49:28 -07:00
Kuniyuki Iwashima
5a7fef12d9 ipv4: fib: Avoid calling fib_trie_table() in fib_new_table() for dying net.
We will call ip_fib_net_exit() from ->exit_rtnl().

All fib_table will be destroyed before devices are unregistered.

During device unregistration, inetdev_destroy() could call
fib_del_ifaddr(), which calls fib_magic(RTM_DELROUTE).

fib_magic() calls fib_new_table(), but we do not want to create
a new table after ip_fib_net_exit() destroys all tables.

As a prep, let's add check_net() before fib_trie_table() in
fib_new_table().

fib_trie_table() is also called from fib_trie_unmerge(), but
fib_get_table() fails first in fib_unmerge(), so the same
problem does not occur there.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260612063225.455191-5-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 11:49:28 -07:00
Kuniyuki Iwashima
49374d87e8 ipv4: fib: Free net->ipv4.{fib_table_hash,notifier_ops} without RTNL.
We will call ip_fib_net_exit() from ->exit_rtnl().

However, some paths will still access net->ipv4.fib_table_hash
after ->exit_rtnl().

For example, fib_flush() is called from fib_disable_ip() for
NETDEV_UNREGISTER.

Let's move kfree(net->ipv4.fib_table_hash) and fib4_notifier_exit()
from ip_fib_net_exit() to its caller.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260612063225.455191-4-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 11:49:28 -07:00
Kuniyuki Iwashima
c993bd0102 ipv4: fib: Call fib_proc_exit() and nl_fib_lookup_exit() at ->pre_exit().
We will call ip_fib_net_exit() from ->exit_rtnl().

Since the exit callbacks are called in the following order,

  1. ->pre_exit()
  ~~~ synchronize_rcu() ~~~
  2. ->exit_rtnl()   : ip_fib_net_exit()
  3. ->exit()        : fib_proc_exit() / nl_fib_lookup_exit()
  4. ->exit_batch()  : fib4_semantics_exit()

the reverse order of fib_net_init() would get messed up.

Let's move fib_proc_exit() and nl_fib_lookup_exit() to ->pre_exit().

This is fine because procfs/netlink access from userspace cannot
occur at this point and synchronize_rcu() is not needed.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260612063225.455191-3-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 11:49:28 -07:00
Kuniyuki Iwashima
64587e936b ipv4: fib: Flush all fib_info in fib_table_flush() during netns dismantle.
Even when fib_table_flush() is called with flush_all true, it does
not flush all fib_info due to this condition:

  !(fi->fib_flags & RTNH_F_DEAD) && !fib_props[fa->fa_type].error)

This creates an implicit ordering between default_device_exit_batch()
and fib_net_exit_batch().

fib_table_flush(flush_all=true) must be called after all devices
are NETDEV_UNREGISTERed, which is after nexthop_flush_dev() marks
RTNH_F_DEAD.

This would cause memory leak if the order were reversed.

fib_table_flush() does not skip non-dead error routes when flush_all
is true:

  !flush_all &&
  !(fi->fib_flags & RTNH_F_DEAD) && fib_props[fa->fa_type].error

Let's merge the two conditions not to skip all non-dead fib_info
during netns dismantle.

Note that we could further apply !flush_all to the basic table
id check and the rtmsg_fib() call in the loop.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260612063225.455191-2-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 11:49:28 -07:00
Fernando Fernandez Mancera
489730ec2a ipv4: handle devconf post-set actions on netlink updates
When IPv4 device configuration parameters are updated via netlink, the
kernel currently only updates the value. This bypasses several
post-modification actions that occur when these same parameters are
updated via sysctl, such as flushing the routing cache or emitting
RTM_NEWNETCONF notifications.

This patch addresses the inconsistency by calling the
devinet_conf_post_set() helper inside inet_set_link_af(). If a flush is
required, we defer it until the netlink attribute parsing loop
completes.

This ensures consistent behavior and side-effects for devconf changes,
regardless of whether they are initiated via sysctl or netlink.

Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Link: https://patch.msgid.link/20260609204520.4670-2-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-13 14:15:53 -07:00
Fernando Fernandez Mancera
3a29b55505 ipv4: centralize devconf sysctl handling
The logic for handling IPv4 devconf sysctls is scattered. Notification
and cache flushes are managed in devinet_conf_proc(), while a separate
ipv4_doint_and_flush() function and DEVINET_SYSCTL_FLUSHING_ENTRY macro
is used for properties that solely require a cache flush.

This patch refactors the sysctl handling by introducing a centralized
helper, devinet_conf_post_set(). This new function evaluates the changed
attribute and handles all necessary operations like triggering netlink
notifications. It returns a boolean indicating whether a routing cache
flush is required.

Note that the boolean is necessary as this function will be re-used for
netlink IPv4 devconf handling where the cache flushing must wait until
all the attributes have been processed.

Finally, this is introducing a small change in behavior for
IPV4_DEVCONF_ROUTE_LOCALNET. As commit d0daebc3d6 ("ipv4: Add
interface option to enable routing of 127.0.0.0/8") intended, the cache
flush should only be performed when ROUTE_LOCALNET changes from 1 to 0.
Unfortunately, this was not true because while implementing it the
DEVINET_SYSCTL_FLUSHING_ENTRY was used for the attribute, making the
code related to it on devinet_conf_proc() dead.

IPV4_DEVCONF_FORWARDING is still being handled separately as it requires
more operations.

Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Link: https://patch.msgid.link/20260609204520.4670-1-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-13 14:15:53 -07:00
Eric Dumazet
91934d4446 tcp: refine tcp_sequence() for the FIN exception
Commit 0e24d17bd9 ("tcp: implement RFC 7323 window retraction
receiver requirements") removed the special FIN case that
was added in commit 1e3bb184e9 ("tcp: re-enable acceptance of
FIN packets when RWIN is 0").

If a peer sends a segment containing data and a FIN flag before
it learns about our window retraction and has a buggy TCP stack,
it might place the FIN one byte beyond what it thinks is the
right edge of the window (i.e., max_window_edge + 1).

The data portion (end_seq - th->fin) will end exactly at max_window_edge.
In this case, we will drop the packet if our receive queue is not empty,
even though the data was sent within the window we previously allowed.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Simon Baatz <gmbnomis@gmail.com>
Link: https://patch.msgid.link/20260608151452.706822-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-13 13:40:37 -07:00
Jakub Kicinski
431662b642 Merge tag 'ipsec-next-2026-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next
Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2026-06-12

1) Replace the open-coded manual cleanup in xfrm_add_policy() error
   path with xfrm_policy_destroy() for consistency with
   xfrm_policy_construct().
   From Deepanshu Kartikey.

2) Limit XFRMA_TFCPAD to a sensible maximum (max IP length, 64k) since
   u32 is excessive for traffic flow confidentiality padding.
   From David Ahern.

3) Add a new netlink message XFRM_MSG_MIGRATE_STATE that
   allows migrating individual IPsec SAs independently of
   their policies. The existing XFRM_MSG_MIGRATE is tightly coupled
   to policy+SA migration, lacks SPI for unique SA identification,
   and cannot express reqid changes or migrate Transport mode
   selectors. The new interface identifies the SA via SPI and mark,
   supports reqid changes, address family changes, encap removal,
   and uses an atomic create+install flow under x->lock to prevent
   SN/IV reuse during AEAD SA migration.
   From Antony Antony.

* tag 'ipsec-next-2026-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next:
  xfrm: add documentation for XFRM_MSG_MIGRATE_STATE
  xfrm: restrict netlink attributes for XFRM_MSG_MIGRATE_STATE
  xfrm: add XFRM_MSG_MIGRATE_STATE for single SA migration
  xfrm: make xfrm_dev_state_add xuo parameter const
  xfrm: extract address family and selector validation helpers
  xfrm: refactor XFRMA_MTIMER_THRESH validation into a helper
  xfrm: move encap and xuo into struct xfrm_migrate
  xfrm: add error messages to state migration
  xfrm: add state synchronization after migration
  xfrm: check family before comparing addresses in migrate
  xfrm: split xfrm_state_migrate into create and install functions
  xfrm: rename reqid in xfrm_migrate
  xfrm: fix NAT-related field inheritance in SA migration
  xfrm: allow migration from UDP encapsulated to non-encapsulated ESP
  xfrm: add extack to xfrm_init_state
  xfrm: remove redundant assignments
  xfrm: Reject excessive values for XFRMA_TFCPAD
  xfrm: cleanup error path in xfrm_add_policy()
====================

Link: https://patch.msgid.link/20260612074725.1760473-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-13 13:16:39 -07:00
Sabrina Dubroca
f51a442dc1 net: remove some unused EXPORT_SYMBOL()s
chtls was using a lot of symbols that no other module requires. Remove
those EXPORT_SYMBOL()s.

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/d124db74f6f0838b652f0ee4b4530964f3cf8d49.1781165969.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-12 16:43:11 -07:00
Eric Dumazet
80a7e3507d ip_tunnel: annotate data-races around t->err_count and t->err_time
ip_tunnel_xmit() runs locklessly (dev->lltx == true).

ipgre_err() and ipip_err() also run locklessly.

We need to add READ_ONCE() and WRITE_ONCE() annotations
around t->err_count and t->err_time.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260611165247.2710257-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-12 16:40:32 -07:00
Matthieu Baerts (NGI0)
1c3e7e0439 tcp: allow mptcp to drop TS for some packets
With TCP-timestamps (padded) taking 12 bytes and ADD_ADDR IPv6 + port
taking 30 bytes, the 40-byte limit for the TCP options is reached. In
this case, it is then not possible to send the address signal.

The idea is to let MPTCP dropping the TCP-timestamps option for some
specific packets, to be able to send some specific pure ACK carrying >28
bytes of MPTCP options, like with this specific ADD_ADDR. A new
parameter is passed from tcp_established_options to the MPTCP side to
indicate if the TCP TS option is used, and if it should be dropped. The
next commit implements the part on MPTCP side, but split into two
patches to help TCP maintainers to identify the modifications on TCP
side. This feature will be controlled by a new add_addr_v6_port_drop_ts
MPTCP sysctl knob.

It is important to keep in mind that dropping the TCP timestamps option
for one packet of the connection could eventually disrupt some
middleboxes: even if it should be unlikely, they could drop the packet
or even block the connection. That's why this new feature will be
controlled by a sysctl knob.

Note that it would be technically possible to squeeze both options into
the header if the ADD_ADDR is first written, and then the TCP timestamps
without the NOPs preceding it. But this means more modifications on TCP
side, plus some middleboxes could still be disrupted by that.

In this implementation, an unused bit is used in mptcp_out_options
structure to avoid passing an address to a local variable. Reading and
setting it needs CONFIG_MPTCP, so the whole block now has this #if
condition: mptcp_established_options() is then no longer used without
CONFIG_MPTCP.

About alternatives, instead of passing a new boolean (has_ts), another
option would be to pass the whole option structure (opts), but
'struct tcp_out_options' is currently defined in tcp_output.c, and it
would need to be exported. Plus that means the removal of the TCP TS
option would be done on the MPTCP side, and not here on the TCP side.
It feels clearer to remove other TCP options from the TCP side, than
hiding that from the MPTCP side.

Yet an other alternative would be to pass the size already taken by the
other TCP options, and have a way to drop them all when needed. But this
feels better to target only the timestamps option where dropping it
should be safe, even if it is currently the only option that would be
set before MPTCP, when MPTCP is used.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260605-net-next-mptcp-add-addr6-port-ts-v2-5-758e7ca73f4d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11 15:33:37 -07:00
Kuniyuki Iwashima
65440a8ce4 ipmr: Convert mr_table.cache_resolve_queue_len to u32.
mr_table.cache_resolve_queue_len is always updated under
spin_lock_bh(&mfc_unres_lock).

Let's convert it to u32.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260609222013.1550355-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11 15:17:30 -07:00
Jakub Kicinski
dad4d4b92a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-7.1-rc8).

Conflicts:

drivers/net/ethernet/wangxun/txgbe/txgbe_aml.c
  f67aead16e ("net: txgbe: rework service event handling")
  57d39faed4 ("net: txgbe: improve functions of AML 40G devices")

net/rds/info.c
  512db8267b ("rds: mark snapshot pages dirty in rds_info_getsockopt()")
  6e94eeb2a2 ("rds: convert to getsockopt_iter")

Adjacent changes:

include/net/sock.h
  1ee90b77b7 ("net: guard timestamp cmsgs to real error queue skbs")
  f0de88303d ("net: make is_skb_wmem() available to modules")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-11 14:33:35 -07:00
Paolo Abeni
64ced6c088 Merge tag 'nf-26-06-10' 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:

1) Revalidate bridge ports, add missing NULL checks to fetch the bridge
   device by the port. From Florian Westphal.

2) Fix netdevice refcount leak in the error path of nft_fwd hardware
   offload function, also from Florian.

3) Unregister helper expectfn callback on conntrack helper module
   removal, otherwise dangling pointer remains in place,
   from Weiming Shi.

4) Fix possible pointer infoleak in getsockopt() IPT_SO_GET_ENTRIES,
   From Kyle Zeng.

5) Validate that device MAC header is present before nf_syslog
   accesses it. From Xiang Mei.

6-8) Three patches to address a possible infoleak of stale stack
     data in three nf_tables expressions, due to mismatch in the
     _init() and _eval() function which is possible since 14fb07130c.
     From Davide Ornaghi and Florian Westphal.

netfilter pull request 26-06-10

* tag 'nf-26-06-10' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nft_meta_bridge: fix stale stack leak via IIFHWADDR register
  netfilter: nft_fib: fix stale stack leak via the OIFNAME register
  netfilter: nft_exthdr: fix register tracking for F_PRESENT flag
  netfilter: nf_log: validate MAC header was set before dumping it
  netfilter: x_tables: avoid leaking percpu counter pointers
  netfilter: nf_conntrack: destroy stale expectfn expectations on unregister
  netfilter: nf_tables_offload: drop device refcount on error
  netfilter: revalidate bridge ports
====================

Link: https://patch.msgid.link/20260610161629.214092-1-pablo@netfilter.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-06-11 12:30:00 +02:00
Paolo Abeni
29899ec61a Merge tag 'ipsec-2026-06-10' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec
Steffen Klassert says:

====================
pull request (net): ipsec 2026-06-10

1) xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags()
   Propagate SKBFL_SHARED_FRAG when paged fragments are moved between
   skbs so ESP can decide whether in-place crypto is safe.

2) xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload
   Replace the unlocked read of xtfs->ra_newskb with a local flag so a
   concurrent reassembly can no longer free first_skb between
   spin_unlock and the post-loop check.

3) xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()
   Prune the inexact bin under xfrm_policy_lock so a concurrent
   xfrm_hash_rebuild() can no longer free it before xfrm_policy_kill()
   dereferences it.

4) xfrm: iptfs: fix ABBA deadlock in iptfs_destroy_state()
   Move hrtimer_cancel() for the output and drop timers ahead of their
   spinlocks, breaking the softirq/lock cycle that could deadlock
   against the timer callbacks on SMP.

5) xfrm: espintcp: do not reuse an in-progress partial send
   Fail a new send when espintcp_push_msgs() returns with emsg->len
   still set, so a blocking caller can no longer overwrite ctx->partial
   while a previous transfer still owns it.

6) esp: fix page frag reference leak on skb_to_sgvec failure
   Add a flag to esp_ssg_unref() to unconditionally unref the source
   scatterlist, releasing the old page references that are otherwise
   leaked when the second skb_to_sgvec() in esp_output_tail() fails.

Please pull or let me know if there are problems.

ipsec-2026-06-10

* tag 'ipsec-2026-06-10' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec:
  esp: fix page frag reference leak on skb_to_sgvec failure
  xfrm: espintcp: do not reuse an in-progress partial send
  xfrm: iptfs: fix ABBA deadlock in iptfs_destroy_state()
  xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()
  xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload
  xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags()
====================

Link: https://patch.msgid.link/20260610140800.2562818-1-steffen.klassert@secunet.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-06-11 12:00:49 +02:00
Davide Ornaghi
ab185e0c4f netfilter: nft_fib: fix stale stack leak via the OIFNAME register
For NFT_FIB_RESULT_OIFNAME the destination register is declared with
len = IFNAMSIZ (four 32-bit registers), but on the lookup-fail,
RTN_LOCAL and oif-mismatch paths nft_fib{4,6}_eval() only writes one
register via "*dest = 0". The remaining three registers are left as
whatever was on the stack in nft_do_chain()'s struct nft_regs, and a
downstream expression that loads the register span can leak that
uninitialised kernel stack to userspace.

The NFTA_FIB_F_PRESENT existence check has the same shape: it is only
meaningful for NFT_FIB_RESULT_OIF, yet it was accepted for any result type
while the eval stores a single byte via nft_reg_store8(), leaving the rest
of the declared span stale.

Fix both:

 - replace the bare "*dest = 0" in the eval with nft_fib_store_result(),
   which strscpy_pad()s the whole IFNAMSIZ for OIFNAME (and is already
   used on the other early-return path), and

 - restrict NFTA_FIB_F_PRESENT to NFT_FIB_RESULT_OIF and declare its
   destination as a single u8, so the marked span matches the one byte
   the eval writes.

Fixes: f6d0cbcf09 ("netfilter: nf_tables: add fib expression")
Suggested-by: Florian Westphal <fw@strlen.de>
Cc: stable@vger.kernel.org
Signed-off-by: Davide Ornaghi <d.ornaghi97@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-10 18:00:19 +02:00
Kyle Zeng
f7f2fbb0e8 netfilter: x_tables: avoid leaking percpu counter pointers
The native and compat get-entries paths copy the fixed rule entry header
from the kernelized rule blob to userspace before overwriting the entry's
counter fields with a sanitized counter snapshot.

On SMP kernels, entry->counters.pcnt contains the percpu allocation
address used by x_tables rule counters. A caller can provide a userspace
buffer that faults during the initial fixed-header copy after pcnt has
been copied but before the later sanitized counter copy runs. The syscall
then returns -EFAULT while leaving the raw percpu pointer in userspace.

Copy only the fixed entry prefix before counters from the kernelized rule
blob, then copy the sanitized counter snapshot into the counter field.
Apply this ordering to the IPv4, IPv6, and ARP native and compat
get-entries implementations so a fault cannot expose the internal percpu
counter pointer.

Fixes: 71ae0dff02 ("netfilter: xtables: use percpu rule counters")
Signed-off-by: Kyle Zeng <kylebot@openai.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-10 17:59:01 +02:00
Weiming Shi
c3009418f9 netfilter: nf_conntrack: destroy stale expectfn expectations on unregister
NAT helpers such as nf_nat_h323 store a raw pointer to module text in
exp->expectfn (e.g. ip_nat_q931_expect). nf_ct_helper_expectfn_unregister()
only unlinks the callback descriptor and never walks the expectation table,
so an expectation pending at module removal survives with a dangling
exp->expectfn into freed module text.

When the expected connection arrives, init_conntrack() invokes
exp->expectfn(), now a stale pointer into the unloaded module. Reproduced
on a KASAN build by loading the H.323 helpers, creating a Q.931
expectation, unloading nf_nat_h323, then connecting to the expected port:

 Oops: int3: 0000 [#1] SMP KASAN NOPTI
 RIP: 0010:0xffffffffa06102d1
  init_conntrack.isra.0 (net/netfilter/nf_conntrack_core.c:1862)
  nf_conntrack_in (net/netfilter/nf_conntrack_core.c:2049)
  ipv4_conntrack_local (net/netfilter/nf_conntrack_proto.c:223)
  nf_hook_slow (net/netfilter/core.c:619)
  __ip_local_out (net/ipv4/ip_output.c:120)
  __tcp_transmit_skb (net/ipv4/tcp_output.c:1715)
  tcp_connect (net/ipv4/tcp_output.c:4374)
  tcp_v4_connect (net/ipv4/tcp_ipv4.c:345)
  __sys_connect (net/socket.c:2167)
 Modules linked in: nf_conntrack_h323 [last unloaded: nf_nat_h323]

Reaching the dangling state requires CAP_SYS_MODULE in the initial user
namespace to remove a NAT helper that still has live expectations, so this
is a robustness fix; leaving an expectation pointing at freed text is wrong
regardless.

Add nf_ct_helper_expectfn_destroy(), which walks the expectation table and
drops every expectation whose ->expectfn matches the descriptor being torn
down. Call it from each NAT helper's exit path after the existing RCU grace
period, so no expectation outlives the code it points at and no extra
synchronize_rcu() is introduced. With the fix, the same reproducer runs to
completion without the Oops.

Fixes: f587de0e2f ("[NETFILTER]: nf_conntrack/nf_nat: add H.323 helper port")
Reported-by: Xiang Mei <xmei5@asu.edu>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-10 17:58:39 +02:00
Alessandro Schino
26aad08a92 esp: fix page frag reference leak on skb_to_sgvec failure
In esp_output_tail(), when esp->inplace is false, the old skb page frags
are replaced with a new page from the xfrm page_frag cache The source
scatterlist (sg) is built from the old frags before the replacement, and
esp_ssg_unref() is responsible for releasing the old page references
after the crypto operation completes

However, if the second skb_to_sgvec() call (which builds the destination
scatterlist from the new page) fails, the code jumps to error_free which
only calls kfree(tmp). The old page frag references captured in the
source scatterlist are never released:

  1 sg[] is built from old frags via skb_to_sgvec() (no extra get_page)
  2 nr_frags is set to 1 and frag[0] is replaced with the new page
  3 Second skb_to_sgvec() fails -> goto error_free

Fix this by adding a bool parameter to esp_ssg_unref() that, when true,
unconditionally unrefs the source scatterlist frags. Since req->src is
not yet initialized by aead_request_set_crypt() at the point of the
error, the source scatterlist is obtained directly via esp_req_sg()
Existing callers pass false to preserve the original behavior

The same issue exists in both esp4 and esp6 as the code is identical

Fixes: cac2661c53 ("esp4: Avoid skb_cow_data whenever possible")
Fixes: 03e2a30f6a ("esp6: Avoid skb_cow_data whenever possible")
Signed-off-by: Alessandro Schino <7991aleschino@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-09 15:58:17 +02:00
Yuyang Huang
3289d17b7a ipv4: igmp: annotate data-races around timer-related fields
/proc/net/igmp walks the multicast list locklessly under RCU and reads
timer-related fields (im->tm_running, im->reporter, im->timer.expires)
to print the timer state of multicast memberships. Concurrently, these
fields are modified under im->lock spinlock in timer management paths
(igmp_stop_timer(), igmp_start_timer(), and igmp_timer_expire()). Fix this
intentional lockless snapshot by annotating the lockless reads with
READ_ONCE() and the updates with WRITE_ONCE().

Signed-off-by: Yuyang Huang <yuyanghuang@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260605014318.3890804-3-yuyanghuang@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-06-09 13:19:33 +02:00
Yuyang Huang
1719841cab ipv4: igmp: annotate data-races around in_dev->mc_count
/proc/net/igmp walks the multicast list for IPv4 interfaces locklessly
under RCU and prints state->in_dev->mc_count. Concurrently, device
init/destruction and multicast join/leave paths update the count
under the RTNL lock. Fix this intentional lockless snapshot by
annotating the read with READ_ONCE() and the updates with WRITE_ONCE().

Signed-off-by: Yuyang Huang <yuyanghuang@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260605014318.3890804-2-yuyanghuang@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-06-09 13:19:33 +02:00
Kuniyuki Iwashima
a543cb49e6 net: Remove rtnl_held of struct fib_dump_filter.
Commit 22e36ea9f5 ("inet: allow ip_valid_fib_dump_req() to
be called with RTNL or RCU") introduced the rtnl_held field in
struct fib_dump_filter to switch __dev_get_by_index() and
dev_get_by_index_rcu() depending on the caller's context.

This field served as an interim measure while we were incrementally
converting all callers of ip_valid_fib_dump_req() to RCU.

Now that all users (IPv4, IPv6, ipmr, ip6mr, and MPLS) have
been converted to RCU, the field is no longer necessary.

Let's remove it.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-8-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-08 17:06:23 -07:00
Jakub Kicinski
d337bc6b27 Merge tag 'nf-next-26-06-07' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next
Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

The following patchset contains Netfilter/IPVS updates for net-next,
this contains updates to address sashiko reports in IPVS and Netfilter
on possible pre-existing issues. This also includes a series to add
refcount for ct helper and timeout to deal with a corner case scenario
with unconfirmed conntracks flying to nfqueue.

1) Add a conn_max sysctl to IPVS to limit the maximum number of
   connections, from Julian Anastasov.

2) Use get_unaligned_be16() to access TCP MSS in nfnetlink_osf,
   from Fernando Fernandez Mancera.

3) Use {READ,WRITE}_ONCE to access helper flags from nfnetlink_helper.

Several patches for the synproxy infrastructure, from Fernando
Fernandez Mancera:

4) Drop packet if TCP timestamp adjustment fails.

5) Continue parsing of TCP timestamp to deal with possible duplicates.

6) Use {get,put}_unaligned_be32() to acess the TCP timestamp.

7) Hold ct->lock to initialize nf_ct_seqadj_init().

Updates for the ct timeout infrastructure, to deal with a corner case
for unconfirmed conntracks flying to nfqueue:

8) Add a refcount to track ct timeout policy use by ct extension,
   release the timeout until the last ct extension drops the refcnt
   on it.

Similar update for the ct helper infrastructure:

9) Dynamic allocation of ct helpers, as a preparation for adding
   refcount to track ct extension use.

10) Move destroy_sibling_or_exp() to nf_conntrack_proto_gre, so
    pptp conntrack helper module removal does not make this code
    unreachable via the helper->destroy callback. This is another
    dependency for the new refcount coming in this series.

11) Add a refcount to track use of it from the ct extension, then
    ct helper and timeout is reachable to the connection until
    it goes away.

12) Remove the genid infrastructure in ct extensions. The primary
    goal was to detect that a ct extension such as ct timeout and
    ct helper went stale for unconfirmed conntrack, either because
    object or module was removed. This deactivates all ct extensions
    though for this unconfirmed conntrack.

13) Call nf_ct_gre_keymap_destroy() if this is a master conntrack
    with a pptp helper only.

sashiko.dev reports one more relevant issue when unsetting the helper
via ctnetlink that I will address in a follow up patch.

Then, two more assorted updates:

14) Avoid a unlikely underflow in bridge VLAN untag, only possible
    if buggy bridge VLAN filtering is buggy, remove WARN_ON_ONCE
    while at it. From David Carlier.

15) Use get_unaligned_be32() in nf_conntrack_tcp to access sack
    extension, from Rosen Penev.

* tag 'nf-next-26-06-07' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()
  netfilter: flowtable: avoid num_encaps underflow on bridge VLAN untag
  netfilter: conntrack: call nf_ct_gre_keymap_destroy() if master helper is pptp
  netfilter: conntrack: revert ct extension genid infrastructure
  netfilter: nf_conntrack_helper: add refcounting from datapath
  netfilter: nf_conntrack_pptp: move GRE specific cleanup to GRE tracker
  netfilter: nf_conntrack_helper: dynamically allocate struct nf_conntrack_helper
  netfilter: cttimeout: detach dataplane timeout policy and repurpose refcount
  netfilter: synproxy: protect nf_ct_seqadj_init() with conntrack lock
  netfilter: synproxy: fix unaligned memory access in timestamp adjustment
  netfilter: synproxy: adjust duplicate timestamp options
  netfilter: synproxy: drop packets if timestamp adjustment fails
  netfilter: nfnetlink_cthelper: use {READ,WRITE}_ONCE for accessing helper flags
  netfilter: nfnetlink_osf: fix mss parsing on big-endian architectures
  ipvs: add conn_max sysctl to limit connections
====================

Link: https://patch.msgid.link/20260607094954.48892-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-08 15:33:35 -07:00
Eric Dumazet
b056e73267 ipv4: remove obsolete EXPORT_SYMBOL() and EXPORT_SYMBOL_GPL()
These symbols no longer need to be exported, they are only used from
vmlinux:

- inet_send_prepare
- inet_splice_eof
- inet_sk_rebuild_header
- inet_current_timestamp
- snmp_fold_field
- snmp_get_cpu_field64
- snmp_fold_field64
- fib_nh_common_release
- fib_nh_common_init
- fib_nexthop_info
- fib_add_nexthop
- ip_build_and_send_pkt
- ipv4_sk_update_pmtu
- ipv4_sk_redirect
- rt_dst_clone

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260604173413.2782008-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-05 17:47:07 -07:00
Pablo Neira Ayuso
6031487d4e netfilter: nf_conntrack_helper: dynamically allocate struct nf_conntrack_helper
Adapt all existing helpers to use a modified version of
nf_ct_helper_init(), to dynamically allocate struct nf_conntrack_helper.

Allocate expect_policy[] built-in into the helper to ensure this area is
reachable after helper removal since a follow up patch adds refcount to
track use of the nf_conntrack_helper structure from packet path so it
remains around until last reference from ct helper extension is dropped.

Export __nf_conntrack_helper_register() which allows to register
nfnetlink_cthelper dynamically allocated helper. Adapt nfnetlink_cthelper
to use the built-in expect_policy[].

This is a preparation patch to add packet path refcounting to helpers.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-05 13:25:18 +02:00
yuan.gao
831d557a3e inet: frags: remove redundant assignment in inet_frag_reasm_prepare()
The assignment is redundant because skb_clone() already copies skb->cb.

Remove the unnecessary code.

Signed-off-by: yuan.gao <yuan.gao@ucloud.cn>
Link: https://patch.msgid.link/20260603065323.2736839-1-yuan.gao@ucloud.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 18:26:11 -07:00
Hyunwoo Kim
32594b0985 inet: frags: fix use-after-free caused by the fqdir_pre_exit() flush
On netns teardown, fqdir_pre_exit() walks the fqdir rhashtable and
flushes every fragment queue that is not yet complete using
inet_frag_queue_flush(). That helper frees all the skbs queued on the
fragment queue but does not set INET_FRAG_COMPLETE, and leaves
q->fragments_tail and q->last_run_head pointing at the freed skbs.
The queue itself stays in the rhashtable.

fqdir_pre_exit() first lowers high_thresh to 0 to stop new queue lookups,
but it cannot stop a fragment that already obtained the queue through
inet_frag_find() earlier and stalled just before taking the queue lock.
Once that fragment resumes after the flush and takes the queue lock,
it passes the INET_FRAG_COMPLETE check and then dereferences the freed
fragments_tail. inet_frag_queue_insert() reads FRAG_CB() and ->len of
that pointer and, on the append path, writes ->next_frag, causing a
slab use-after-free. IPv6, nf_conntrack_reasm6 and 6lowpan reassembly
share the same flush path and are affected as well.

Reset rb_fragments, fragments_tail and last_run_head in
inet_frag_queue_flush() so a flushed queue no longer points at the
freed skbs. A fragment that resumes after the flush and takes the
queue lock then finds an empty queue and starts a new run instead of
dereferencing the freed fragments_tail. ip_frag_reinit() already
performed this reset after its own flush, so drop the now duplicate
code there.

Cc: stable@vger.kernel.org
Fixes: 006a5035b4 ("inet: frags: flush pending skbs in fqdir_pre_exit()")
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Link: https://patch.msgid.link/ah6ukYq5G98LshdA@v4bel
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 18:05:23 -07:00
Jakub Kicinski
8d72997dab Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-7.1-rc7).

Silent conflicts:

net/wireless/nl80211.c
  cb9959ab5f ("wifi: cfg80211: enforce HE/EHT cap/oper consistency")
  a384ae9699 ("wifi: cfg80211: move AP HT/VHT/... operation to beacon info")
https://lore.kernel.org/aiGJDaHV4UlCexIQ@sirena.org.uk

Conflicts:

drivers/net/wireless/intel/iwlwifi/mld/ap.c
  a342c99cb7 ("wifi: iwlwifi: mld: honor BSS_CHANGED_BEACON_ENABLED")
  9bf1b409af ("wifi: iwlwifi: mld: send tx power constraints before link activation")
https://lore.kernel.org/ah2bfedhV45ZxMO8@sirena.org.uk

drivers/net/wireless/intel/iwlwifi/pcie/drv.c
  093305d801 ("wifi: iwlwifi: pcie: simplify the resume flow if fast resume is not used")
  e2323929a6 ("wifi: iwlwifi: pcie: add debug print for resume flow if powered off")
https://lore.kernel.org/ah2bfedhV45ZxMO8@sirena.org.uk

Adjacent changes:

drivers/net/ethernet/airoha/airoha_eth.c
  b38cae85d1 ("net: airoha: Fix use-after-free in metadata dst teardown")
  ec6c391bcc ("net: airoha: Introduce airoha_gdm_dev struct")

drivers/net/ethernet/microchip/lan743x_main.c
  8173d22b21 ("net: lan743x: permit VLAN-tagged packets up to configured MTU")
  e3c6508a46 ("net: lan743x: avoid netdev-based logging before netdev registration")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 15:29:04 -07:00
Sechang Lim
3c94f241f7 udp: clear skb->dev before running a sockmap verdict
On the UDP receive path skb->dev is repurposed as dev_scratch (the
truesize/state cache set by udp_set_dev_scratch()), through the
union { struct net_device *dev; unsigned long dev_scratch; } in sk_buff.

When a UDP socket is in a sockmap, sk_data_ready is
sk_psock_verdict_data_ready(), which calls udp_read_skb() -> recv_actor()
(sk_psock_verdict_recv) to run the attached SK_SKB verdict program in softirq.
If that program calls a socket-lookup helper (bpf_sk_lookup_tcp/udp,
bpf_skc_lookup_tcp), bpf_skc_lookup() does:

	if (skb->dev)
		caller_net = dev_net(skb->dev);

skb->dev still holds the dev_scratch value (a non-NULL integer), so dev_net()
dereferences it as a struct net_device * and the kernel takes a general
protection fault on a non-canonical address in softirq:

  Oops: general protection fault, probably for non-canonical address 0x1010000800004a0
  CPU: 1 UID: 0 PID: 1406 Comm: syz.2.19 Not tainted 7.1.0-rc6 #1 PREEMPT(full)
  RIP: 0010:bpf_skc_lookup net/core/filter.c:7033 [inline]
  RIP: 0010:bpf_sk_lookup+0x45/0x160 net/core/filter.c:7047
  Call Trace:
   <IRQ>
   bpf_prog_4675cb904b7071f8+0x12e/0x14e
   bpf_prog_run_pin_on_cpu+0xc6/0x1f0
   sk_psock_verdict_recv+0x1ba/0x350
   udp_read_skb+0x31a/0x370
   sk_psock_verdict_data_ready+0x2e3/0x600
   __udp_enqueue_schedule_skb+0x4c8/0x650
   udpv6_queue_rcv_one_skb+0x3ec/0x740
   udp6_unicast_rcv_skb+0x11d/0x140
   ip6_protocol_deliver_rcu+0x61e/0x950
   ip6_input_finish+0xa9/0x150
   NF_HOOK+0x286/0x2f0
   ip6_input+0x117/0x220
   NF_HOOK+0x286/0x2f0
   __netif_receive_skb+0x85/0x200
   process_backlog+0x374/0x9a0
   __napi_poll+0x4f/0x1c0
   net_rx_action+0x3b0/0x770
   handle_softirqs+0x15a/0x460
   do_softirq+0x57/0x80
   </IRQ>

The rmem charge that dev_scratch accounted for is released by skb_recv_udp() on
dequeue, just above, so the scratch is dead by the time recv_actor() runs. Clear
skb->dev so bpf_skc_lookup() falls back to sock_net(skb->sk), which
skb_set_owner_sk_safe() set just above.

Fixes: 965b57b469 ("net: Introduce a new proto_ops ->read_skb()")
Cc: stable@vger.kernel.org
Signed-off-by: Sechang Lim <rhkrqnwk98@gmail.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260603162737.697215-1-rhkrqnwk98@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 09:01:51 -07:00
Antony Antony
231a1744dc xfrm: add extack to xfrm_init_state
Add a struct extack parameter to xfrm_init_state() and pass it
through to __xfrm_init_state(). This allows validation errors detected
during state initialization to propagate meaningful error messages back
to userspace.

xfrm_state_migrate() now passes extack so that errors from the
XFRM_MSG_MIGRATE_STATE path are properly reported. Callers without an
extack context (af_key, ipcomp4, ipcomp6) pass NULL, preserving their
existing behaviour.

Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Antony Antony <antony.antony@secunet.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04 12:22:35 +02:00
Eric Dumazet
a02a765bd5 mptcp: change mptcp_established_options() to return opt_size
Instead of passing opt_size address to mptcp_established_options(),
change this function to return it by value.

This removes the need for an expensive stack canary in
tcp_established_options() when CONFIG_STACKPROTECTOR_STRONG=y.

$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-92 (-92)
Function                                     old     new   delta
tcp_options_write.isra                      1423    1407     -16
mptcp_established_options                   2746    2720     -26
tcp_established_options                      553     503     -50
Total: Before=22110750, After=22110658, chg -0.00%

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602125138.2317015-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:40 -07:00
Eric Dumazet
3070d0294e ipv4: raw: remove six obsolete EXPORT_SYMBOL_GPL()
IPv6 can not be a module anymore, we no longer need to export:

- raw_hash_sk()
- raw_unhash_sk()
- raw_abort()
- raw_seq_start()
- raw_seq_next()
- raw_seq_stop()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260602165036.2712408-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 18:53:37 -07:00
Eric Dumazet
d3915a1f5a ipv4: restrict IPOPT_SSRR and IPOPT_LSRR options
This patch restricts setting Loose Source and Record Route (LSRR)
and Strict Source and Record Route (SSRR) IP options to users
with CAP_NET_RAW capability.

This prevents unprivileged applications from forcing packets to route
through attacker-controlled nodes to leak TCP ISN and possibly other
protocol information.

While LSRR and SSRR are commonly filtered in many network environments,
they may still be supported and forwarded along some network paths.

RFC 7126 (Recommendations on Filtering of IPv4 Packets Containing
IPv4 Options) recommend to drop these options in 4.3 and 4.4.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Tamir Shahar <tamirthesis@gmail.com>
Reported-by: Amit Klein <aksecurity@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260602161547.2642155-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 18:53:14 -07:00
Kuniyuki Iwashima
e10902df24 tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req().
syzbot reported a weird reqsk->rsk_refcnt underflow in
__inet_csk_reqsk_queue_drop().

The captured reqsk_put() in __inet_csk_reqsk_queue_drop()
is called only when it successfully removes reqsk from ehash.

Moreover, reqsk_timer_handler() calls another reqsk_put()
after that.

This indicates that the reqsk was missing both refcnts for
ehash and the timer itself.

Since all the syzbot reports had PREEMPT_RT enabled, the only
possible scenario is that reqsk_queue_hash_req() is preempted
after mod_timer() and before refcount_set(), and then the timer
triggered after 1s aborts the reqsk due to its listener's close().

Let's wrap mod_timer() and refcount_set() with
preempt_disable_nested() and preempt_enable_nested().

Note that inet_ehash_insert() holds the normal spin_lock()
(mutex in PREEMPT_RT), so it must be called outside of
preempt_disable_nested(), but this is fine.

The lookup path just ignores 0 sk_refcnt entries in ehash
and tries to create another reqsk, but this will fail at
inet_ehash_insert().

[0]:
refcount_t: underflow; use-after-free.
WARNING: lib/refcount.c:28 at refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28, CPU#0: ktimers/0/16
Modules linked in:
CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28
Code: e4 7d d1 0a 67 48 0f b9 3a eb 4a e8 38 3d 23 fd 48 8d 3d e1 7d d1 0a 67 48 0f b9 3a eb 37 e8 25 3d 23 fd 48 8d 3d de 7d d1 0a <67> 48 0f b9 3a eb 24 e8 12 3d 23 fd 48 8d 3d db 7d d1 0a 67 48 0f
RSP: 0000:ffffc90000157948 EFLAGS: 00010246
RAX: ffffffff84a1301b RBX: 0000000000000003 RCX: ffff88801ca98000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffffff8f72ae00
RBP: ffffffff99ae3b01 R08: ffff88801ca98000 R09: 0000000000000005
R10: 0000000000000100 R11: 0000000000000004 R12: ffff8880425ef568
R13: ffff8880425ef4f8 R14: ffff8880425ef578 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888126386000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7b46710e9c CR3: 000000000dbb6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __refcount_sub_and_test include/linux/refcount.h:400 [inline]
 __refcount_dec_and_test include/linux/refcount.h:432 [inline]
 refcount_dec_and_test include/linux/refcount.h:450 [inline]
 reqsk_put include/net/request_sock.h:136 [inline]
 __inet_csk_reqsk_queue_drop+0x3ce/0x440 net/ipv4/inet_connection_sock.c:1007
 reqsk_timer_handler+0x651/0xdf0 net/ipv4/inet_connection_sock.c:1137
 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x6a3/0x9f0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0x67/0x170 kernel/time/timer.c:2403
 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 run_ktimerd+0x69/0x100 kernel/softirq.c:1151
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 kthread+0x388/0x470 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: d2d6422f8b ("x86: Allow to enable PREEMPT_RT.")
Reported-by: syzbot+e809069bc15f26300526@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/6a1a7bcf.0a9e871e.332604.000b.GAE@google.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20260601182101.3183993-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-02 11:55:56 -07:00
Eric Dumazet
ceac8dbce6 tcp: change bpf_skops_hdr_opt_len() signature
Some compilers do not inline bpf_skops_hdr_opt_len() from
tcp_established_options(), forcing an expensive stack canary
when CONFIG_STACKPROTECTOR_STRONG=y.

Change bpf_skops_hdr_opt_len() to return @remaining by value
to remove this stack canary from TCP fast path.

$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 0/0 grow/shrink: 1/1 up/down: 10/-59 (-49)
Function                                     old     new   delta
bpf_skops_hdr_opt_len                        297     307     +10
tcp_established_options                      574     515     -59
Total: Before=31456795, After=31456746, chg -0.00%

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260601093819.469626-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-02 11:14:59 -07:00
Neal Cardwell
4490516d21 tcp_bbr: fix SPDX-License-Identifier to be GPL-2.0 OR BSD-3-Clause
Since TCP BBR congestion control was introduced in
commit 0f8782ea14 ("tcp_bbr: add BBR congestion control")
it has always been offered as "Dual BSD/GPL":

  MODULE_LICENSE("Dual BSD/GPL");

A GPL-2.0-only SPDX header was erroneously added in the recent
commit 2ed4b46b4f ("net: Add SPDX ids to some source files").

This commit revises the tcp_bbr.c SPDX-License-Identifier to note that
this file is licensed as "GPL-2.0 OR BSD-3-Clause".

Fixes: 2ed4b46b4f ("net: Add SPDX ids to some source files")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Van Jacobson <vanj@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Tim Bird <tim.bird@sony.com>
Link: https://patch.msgid.link/20260531183558.2337381-1-ncardwell.sw@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-01 16:51:08 -07:00
Paolo Abeni
c2c0486c56 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts:

drivers/net/ethernet/microsoft/mana/mana_en.c:
  17bfe0a8c0 ("net: mana: Add NULL guards in teardown path to prevent panic on attach failure")
  d07efe5a6e ("net: mana: Use per-queue allocation for tx_qp to reduce allocation size")

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-06-01 13:42:12 +02:00
Jakub Kicinski
c84ff04def Merge tag 'ipsec-2026-05-29' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec
Steffen Klassert says:

====================
pull request (net): ipsec 2026-05-29

1) xfrm: route MIGRATE notifications to caller's netns
   Thread the caller's netns through km_migrate() so that
   MIGRATE notifications go to the issuing netns, fixing both the
   init_net listener leak and MOBIKE notifications inside
   non-init netns. From Maoyi Xie.

2) xfrm: ipcomp: Free destination pages on acomp errors
   Move the out_free_req label up so that allocated destination
   pages are released on decompression errors, not only on success.
   From Herbert Xu.

3) xfrm: Check for underflow in xfrm_state_mtu
   Reject configurations that cause xfrm_state_mtu() to underflow,
   preventing a negative TFCPAD value from becoming a memset size
   that triggers an out-of-bounds write of several terabytes.
   From David Ahern.

4) xfrm: ah: use skb_to_full_sk in async output callbacks
   Convert the possibly-incomplete skb->sk to a full socket pointer
   in async AH callbacks so that a request_sock or timewait_sock
   never reaches xfrm_output_resume() downstream consumers.
   From Michael Bommarito.

5) Add and revert: esp: fix page frag reference leak on skb_to_sgvec failure
   The patch does not fix te issue completely.

6) xfrm: esp: restore combined single-frag length gate
   Check the aligned post-trailer combined length against a page limit
   in the fast path, preventing skb_page_frag_refill() from falling
   back to a page too small for the destination scatterlist.
   From Jingguo Tan.

7) xfrm: iptfs: reset runtime state when cloning SAs
   Reinitialise the clone's mode_data runtime objects before
   publishing it, preventing queued skbs from being freed with
   list state copied from the original SA when migration fails.
   From Shaomin Chen.

8) xfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exit
   Flush policy tables and drain the workqueue in a .pre_exit handler
   so that cleanup_net() pays one RCU grace period per batch instead
   of one per namespace, fixing stalls at high CLONE_NEWNET rates.
   From Usama Arif.

9) xfrm: input: hold netns during deferred transport reinjection
   Take a netns reference when queueing deferred transport reinjection
   work and drop it after the callback completes, keeping the skb->cb
   net pointer valid until the deferred work runs.
   From Zhengchuan Liang.

* tag 'ipsec-2026-05-29' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec:
  Revert "esp: fix page frag reference leak on skb_to_sgvec failure"
  xfrm: input: hold netns during deferred transport reinjection
  xfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exit
  xfrm: iptfs: reset runtime state when cloning SAs
  xfrm: esp: restore combined single-frag length gate
  esp: fix page frag reference leak on skb_to_sgvec failure
  xfrm: ah: use skb_to_full_sk in async output callbacks
  xfrm: Check for underflow in xfrm_state_mtu
  xfrm: ipcomp: Free destination pages on acomp errors
  xfrm: route MIGRATE notifications to caller's netns
====================

Link: https://patch.msgid.link/20260529092648.3878973-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-29 12:57:23 -07:00
Steffen Klassert
6851161feb Revert "esp: fix page frag reference leak on skb_to_sgvec failure"
This reverts commit 2982e599ff.

The patch does not fully fix the issue and the Author does
not match the 'Signed-off-by:' tag, so revert it for now.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-05-29 10:23:25 +02:00
Jakub Kicinski
d44646fc9e Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-7.1-rc6).

Conflicts:

drivers/net/phy/air_en8811h.c
  d895767c33 ("net: phy: air_en8811h: add AN8811HB MCU assert/deassert support")
  dddfadd751 ("net: phy: Add Airoha phy library for shared code")
  5226bb6634 ("net: phy: air_phy_lib: Factorize BuckPBus register accessors")
  e08f0ea6da ("net: phy: Rename Airoha common BuckPBus register accessors")

net/sched/sch_netem.c
  a2f6ed7b48 ("net/sched: netem: add per-impairment extended statistics")
  9552b11e3e ("net/sched: fix packet loop on netem when duplicate is on")

Adjacent changes:

drivers/dpll/zl3073x/core.c
  c1224569ce ("dpll: zl3073x: make frequency monitor a per-device attribute")
  54e65df8cf ("dpll: zl3073x: report FFO as DPLL vs input reference offset")

net/iucv/af_iucv.c
  347fdd4df8 ("af_iucv: convert to getsockopt_iter")
  3589d20a66 ("net/iucv: fix locking in .getsockopt")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-28 14:02:21 -07:00
Eric Dumazet
509323077e tunnels: do not assume transport header in iptunnel_pmtud_check_icmp()
In some cases, iptunnel_pmtud_check_icmp() can be called while
skb transport header is not set.

This triggers an out-of-bound access, because
(typeof(skb->transport_header))~0U is 65535.

Access the icmp header based on IPv4 network header,
after making sure icmp->type is present in skb linear part.

Note that iptunnel_pmtud_check_icmpv6()) is fine.

Fixes: 4cb47a8644 ("tunnels: PMTU discovery support for directly bridged IP packets")
Reported-by: Damiano Melotti <melotti@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260522115512.1519110-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-26 18:11:47 -07:00
Eric Dumazet
b4bc943530 tunnels: load network headers after skb_cow() in iptunnel_pmtud_build_icmp[v6]()
Sashiko found that iptunnel_pmtud_build_icmp() and
iptunnel_pmtud_build_icmpv6() were caching ip_hdr() and ipv6_hdr()
before an skb_cow() call which can reallocate skb->head.

Fix this possible UAF by initializing the local variables
after the skb_cow() call.

Remove skb_reset_network_header() calls which were not needed.

Fixes: 4cb47a8644 ("tunnels: PMTU discovery support for directly bridged IP packets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Link: https://patch.msgid.link/20260525201335.2361845-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-26 18:10:25 -07:00
Jakub Kicinski
09cfce83e8 Merge tag 'nf-next-26-05-25' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next
Florian Westphal says:

====================
netfilter: updates for net-next

The following patchset contains Netfilter fixes and small enhancements:

1) Disable 32-bit x_tables compatibility (32bit binaries on 64bit
   kernel) interface in user namespaces.  This is 'last warning'
   before this is removed for good.

2) Add a configuration toggle for netfilter GCOV profiling. Provide
   dedicated toggles for ipset and ipvs.

3) Remove modular support for nfnetlink and restrict it to built-in only.
   From Pablo Neira Ayuso.

4) Use per-rule hash initval in nf_conncount. This avoids unecessary
   lock contention with short keys (e.g. conntrack zones) in different
   namespaces.

5) Use nf_ct_exp_net() in ctnetlink expectation dumps.
   From Pratham Gupta.

6) Remove a dead conditional in nft_set_rbtree.

7) Fix conntrack helper policy updates to apply per-class values correctly.
   From David Carlier.

8) Fix an off-by-one OOB read in nf_conntrack_irc:parse_dcc(). Use strict
   less-than comparison in the newline search loop to respect the
   exclusive-end pointer convention.  From Muhammad Bilal.

9) Fix typos in nf_conntrack_proto_tcp comments.  From Avinash Duduskar.

10) Restore performance optimization in nft_set_pipapo_avx2 by passing
    the next map index. Refactor lookup logic for clarity and add a
    DEBUG_NET check to document this.

11) Avoid (harmless) u16 overflow in nf_conntrack_ftp when parsing FTP PORT
    and EPRT commands.  Ignore commands where single octet exceeds 255.
    From Giuseppe Caruso.

Patch 12, which removes incorrect (and obviously unused) code from
nft_byteorder was kept back to avoid a net -> net-next merge conflict.

* tag 'nf-next-26-05-25' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: nf_conntrack_ftp: avoid u16 overflows
  netfilter: nft_set_pipapo_avx2: restore performance optimization
  netfilter: nf_conntrack_proto_tcp: fix typos in comments
  netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read
  netfilter: nfnl_cthelper: apply per-class values when updating policies
  netfilter: nft_set_rbtree: remove dead conditional
  netfilter: ctnetlink: use nf_ct_exp_net() in expectation dump
  netfilter: nf_conncount: use per-rule hash initval
  netfilter: allow nfnetlink built-in only
  netfilter: add option for GCOV profiling
  netfilter: x_tables: disable 32bit compat interface in user namespaces
====================

Link: https://patch.msgid.link/20260525182924.28456-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-26 18:07:28 -07:00
Yuyang Huang
061c0aa740 ipv4: igmp: annotate data-races around im->users
/proc/net/igmp walks IPv4 multicast memberships under RCU and
prints im->users without holding RTNL, while multicast join and leave
paths update the field while holding RTNL. Annotate this intentional
lockless snapshot with READ_ONCE() and the matching writers with
WRITE_ONCE().

Signed-off-by: Yuyang Huang <sigefriedhyy@gmail.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260522093906.39764-1-sigefriedhyy@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-25 11:08:59 -07:00
Florian Westphal
403cec8ab6 netfilter: add option for GCOV profiling
Similar to a few other subsystems: add a new config toggle to
enable netfilter gcov profiling in netfilter, including ebtables,
arptables and so on.

ipset and ipvs gain their own, dedicated toggles.

Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-05-24 22:55:47 +02:00
Florian Westphal
ec1806a730 netfilter: x_tables: disable 32bit compat interface in user namespaces
This feature is required to use 32bit arp/ip/ip6/ebtables binaries on
64bit kernels.  I don't think there are many users left.

Support has been a compile-time option since 2021 and defaults to off
since 2023.

The XTABLES_COMPAT config option is already off in many distributions
including Debian and Fedora.

Give a few more months before complete removal but disable support in
user namespaces already.

Assisted-by: Claude:claude-sonnet-4-6
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-05-24 22:55:37 +02:00
Eric Dumazet
87a1e0fe77 ipv4: free net->ipv4.sysctl_local_reserved_ports after unregister_net_sysctl_table()
ipv4_sysctl_exit_net() is currently freeing net->ipv4.sysctl_local_reserved_ports
too soon.

Only after unregister_net_sysctl_table() we can be sure no threads can possibly
use the sysctls, including /proc/sys/net/ipv4/ip_local_reserved_ports.

Fixes: 122ff243f5 ("ipv4: make ip_local_reserved_ports per netns")
Reported-by: Ji'an Zhou <eilaimemedsnaimel@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://patch.msgid.link/20260521122147.3584624-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-22 19:05:31 -07:00
Jingguo Tan
dfa0d7b0ff xfrm: esp: restore combined single-frag length gate
The ESP out-of-place fast path appends the trailer in esp_output_head()
before esp_output_tail() allocates the destination page frag. The
head-side gate currently checks skb->data_len and tailen separately, but
the tail code allocates a single destination frag from the combined
post-trailer skb->data_len.

Reject the page-frag fast path when the combined aligned length exceeds a
page. Otherwise skb_page_frag_refill() may fall back to a single page while
the destination sg still spans the combined skb->data_len.

Restore this combined-length page gate for both IPv4 and IPv6.

Fixes: 5bd8baab08 ("esp: limit skb_page_frag_refill use to a single page")
Cc: stable@vger.kernel.org
Signed-off-by: Lin Ma <malin89@huawei.com>
Signed-off-by: Chenyuan Mi <michenyuan@huawei.com>
Signed-off-by: Jingguo Tan <tanjingguo@huawei.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-05-22 09:20:26 +02:00
e521588
2982e599ff esp: fix page frag reference leak on skb_to_sgvec failure
In esp_output_tail(), when esp->inplace is false, the old skb page frags
are replaced with a new page from the xfrm page_frag cache. The source
scatterlist (sg) is built from the old frags before the replacement, and
esp_ssg_unref() is responsible for releasing the old page references
after the crypto operation completes.

However, if the second skb_to_sgvec() call (which builds the destination
scatterlist from the new page) fails, the code jumps to error_free which
only calls kfree(tmp). The old page frag references captured in the
source scatterlist are never released:

  1. sg[] is built from old frags via skb_to_sgvec() (no extra get_page)
  2. nr_frags is set to 1 and frag[0] is replaced with the new page
  3. Second skb_to_sgvec() fails -> goto error_free
  4. kfree(tmp) frees the sg[] memory but old frags are not unref'd
  5. kfree_skb() only releases frag[0] (the new page), not the old ones

Fix this by adding a bool parameter to esp_ssg_unref() that, when true,
unconditionally unrefs the source scatterlist frags without checking
req->src and req->dst, since those fields are not yet initialized by
aead_request_set_crypt() at the point of the error. Existing callers
pass false to preserve the original behavior.

The same issue exists in both esp4 and esp6 as the code is identical.

Fixes: cac2661c53 ("esp4: Avoid skb_cow_data whenever possible")
Fixes: 03e2a30f6a ("esp6: Avoid skb_cow_data whenever possible")

Signed-off-by: Alessandro Schino <7991aleschino@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-05-22 09:19:37 +02:00