linux-stable.git/include/net, branch v7.2

Merge tag 'nf-26-08-10' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf

2026-08-12T01:32:18+00:00

Pablo Neira Ayuso says:

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

The following patchset contains Netfilter/IPVS fixes for net. Still
large batch for this late -rc cycle but at least half of these fixes
in this batch have been cooking for several weeks before:

1) Fix race between ipset list:set GC and swap, use write_lock instead
   of rcu read lock section when accessing the index to ensure
   interference with ip_set_swap(), from Xiang Mei.

2) Release template conntrack in bridge conntrack when packet is
   neither IPv4 nor IPv6 before setting skb as untracked.
   From Zhiling Zou.

3) A series of 3 patches for IPVS to address sashiko reports:
   Schedulers read destination overload state while connection
   accounting and destination configuration can update it concurrently.
   The first patch adds a single total connection counter. The second
   patch uses it to identify threshold crossings precisely, and updates
   OVERLOAD at the crossings and on a threshold edit under dst_lock.
   The third patch moves configuration-controlled AVAILABLE to a
   separate cflags word, so it cannot clobber OVERLOAD through an
   unrelated read-modify-write update.

4) Log invalid packets in TCP and SCTP connection tracking to address
   a deadlock when nfnetlink_log is used as logging backend and the
   nfnetlink_log conntrack glue support is used. From Zihan Xi.

5) Wait for rcu grace period before releasing pernet state in
   nfnetlink_log, otherwise packets can end up access already released
   memory, triggering UaF. From Florian Westphal.

6) IPVS needs to reset IP information in control buffer in skbuff when
   encapsulating IP packets in ICMP, from Kyle Zeng.

7) IPVS needs to validate ihl field of inner headers in when handling
   ICMP response, from Julian Anastasov.

8) Remove a WARN_ON_ONCE reachable from the nf_tables hardware offload
   when triggering ENOMEM on GFP_KERNEL allocation,
   from Alexey Velichayshiy.

9) Publish reply tuple into the flowtable hashtable first, otherwise
   GC might walk over a released tuple when insertion of the original
   tuple fail. From Jeremy Jean.

10) Elide counter increment when replacing an ipset element,
    from Florian Westphal.

11) Remove unneeded ipset accounting resets on destruction/flush,
    from Florian Westphal.

* tag 'nf-26-08-10' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: ipset: let destroy callbacks adjust ext mem size
  netfilter: ipset: fix list type element drift bug
  netfilter: flowtable: publish GC-visible tuple last
  netfilter: nf_tables_offload: suppress WARN_ON_ONCE for ENOMEM in abort path
  ipvs: revalidate ihl to prevent out-of-bounds access
  ipvs: clear IPv4 options after rebasing tunnel ICMP errors
  netfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state
  netfilter: nf_conntrack: defer invalid log until after unlock
  ipvs: separate destination availability state
  ipvs: properly update the overload flag on dest edit
  ipvs: add totalconns for dest
  netfilter: bridge: release template ct on non-IP path
  netfilter: ipset: fix refcount race between list:set GC and swap
====================

Link: https://patch.msgid.link/20260810190621.894119-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski

ipv4: fix use-after-free in fib_nhc_update_mtu()

2026-08-11T09:25:10+00:00

fib_nhc_update_mtu() walks the nexthop exception table under RTNL, but
RTNL does not serialize this walk with PMTU exception updates. The walk
uses rcu_dereference_protected() with a constant true condition without
holding fnhe_lock.

The following interleaving can therefore occur:

  CPU 0                              CPU 1
  fib_nhc_update_mtu()               update_or_create_fnhe()
    load fnhe                          spin_lock_bh(&fnhe_lock)
                                       fnhe_remove_oldest()
                                         unlink fnhe
                                         kfree_rcu(fnhe, rcu)
    
    access fnhe after grace period

KASAN reported:

  BUG: KASAN: slab-use-after-free in fib_nhc_update_mtu+0x3df/0x410
  Read of size 8 at addr ffff888107d49000 by task poc/90
  Call Trace:
   fib_nhc_update_mtu+0x3df/0x410
   fib_sync_mtu+0x7a/0xd0
   fib_netdev_event+0x229/0x3f0
   netif_set_mtu_ext+0x33a/0x570
   dev_set_mtu+0x88/0x120

The same walk updates fnhe_pmtu and fnhe_mtu_locked. These fields form a
pair and other writers serialize them with fnhe_lock. RCU alone prevents
reclamation, but would still allow concurrent writers to leave a mixed
pair.

Walk the table under RCU and acquire fnhe_lock only while updating each
exception. RCU keeps the current entry alive while the short critical
section serializes its paired PMTU fields. This avoids holding the global
lock while scanning all 2048 buckets for every nexthop.

Fixes: af7d6cce5369 ("net: ipv4: update fnhe_pmtu when first hop's MTU changes")
Cc: stable@vger.kernel.org
Suggested-by: Ido Schimmel 
Signed-off-by: Chengfeng Ye 
Reviewed-by: Ido Schimmel 
Link: https://patch.msgid.link/20260807181710.1178747-1-nicoyip.dev@gmail.com
Signed-off-by: Paolo Abeni

net/sched: act_gact, act_police: range check the fallback control action

2026-08-10T23:00:19+00:00

tcf_action_check_ctrlact() range checks the primary control action:

	if (!opcode)
		ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0;

TC_ACT_VALUE_MAX is TC_ACT_TRAP, so kernel-internal verdicts above it
cannot be set that way. But act_gact and act_police each carry a second,
independent control action supplied by user space that never reaches that
helper - TCA_GACT_PROB.paction and TCA_POLICE_RESULT. Both only reject
TC_ACT_GOTO_CHAIN, so any other value is stored verbatim and returned
verbatim from the action.

In particular user space can store TC_ACT_CONSUMED, which is
TC_ACT_VALUE_MAX + 1 and is deliberately not part of the UAPI value
range. That verdict tells every caller the action took ownership of the
skb, so nobody frees it: sch_handle_ingress(), sch_handle_egress() and
tcf_qevent_handle() all deliberately skip the free for it. The result is
one leaked sk_buff plus its data buffer per packet traversing the filter,
unbounded, for all traffic on the chain including kernel-generated
packets.

Both are trivially deterministic. act_gact clamps tcfg_pval to >= 1, so
with pval = 1 gact_determ() returns the fallback for every packet.
act_police has no mandatory rate, so rate = 0 leaves tcfp_mtu = ~0 and
tcf_police_mtu_check() always passes.

TC_ACT_CONSUMED was added by commit 720f22fed81b ("net: sched: refactor
reinsert action"), after both goto-chain guards were written:
commit 9469f375ab09 ("net/sched: act_gact: disallow 'goto chain' on
fallback control action") and
commit c08f5ed5d625 ("net/sched: act_police: disallow 'goto chain' on
fallback control action"). Neither guard was widened when the new
verdict appeared.

Factor the existing range test out of tcf_action_check_ctrlact() as
tcf_action_valid() and apply it to both fallbacks. The helper cannot call
tcf_action_check_ctrlact() directly because that also allocates a
goto_chain, which is exactly what these two sites must not do.

Reproduced on v7.2-rc6: kmemleak reports one leaked 232-byte
skbuff_head_cache object plus its 704-byte data buffer per packet. With
this patch both configurations are rejected with -EINVAL and kmemleak
reports none.

Fixes: 720f22fed81b ("net: sched: refactor reinsert action")
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: Hyunjung Ko 
Acked-by: Jamal Hadi Salim 
Tested-by: Victor Nogueira 
Link: https://patch.msgid.link/20260806101252.809593-1-hj351016@gmail.com
Signed-off-by: Jakub Kicinski

ipvs: revalidate ihl to prevent out-of-bounds access

2026-08-10T18:27:15+00:00

While the outer IP header is already pulled into the skb head,
we must be careful and revalidate the embedded headers after
reading them from the skb frags to prevent out-of-bounds
access.

One such place reported by Sashiko is ip_vs_nat_icmp() where
local process can change the ihl field and after
skb_ensure_writable() we can see larger value which is a
problem for the ip_send_check(cih) calls.

Add check to drop the packet if the ihl field is changed.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Link: https://sashiko.dev/#/patchset/20260730183506.87473-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso

ipvs: separate destination availability state

2026-08-10T18:23:35+00:00

IPVS configuration paths update destination availability while connection
accounting updates destination overload state. The two independent states
share dest->flags, so their read-modify-write updates can race and lose one
another.

Keep OVERLOAD in flags, where the preceding patch serializes its updates
with dst_lock, and move AVAILABLE to cflags. This keeps configuration-
controlled availability out of the scheduler hot cacheline until a
scheduler needs to check it. It also prevents availability updates from
clobbering overload state.

The destination status bits are not exposed through the IPVS sockopt or
netlink interfaces, so keep their definitions in the internal IPVS header.

Readers can still observe stale destination state; this does not provide a
cross-field snapshot.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reported-by: Yizhou Zhao 
Reported-by: Yuxiang Yang 
Reported-by: Ao Wang 
Reported-by: Xuewei Feng 
Reported-by: Qi Li 
Reported-by: Ke Xu 
Link: https://lore.kernel.org/all/8913381c-1e02-35c7-0ec4-61de5a12fd35@ssi.bg/
Assisted-by: Claude-Code:GLM-5.2
Suggested-by: Julian Anastasov 
Signed-off-by: Yizhou Zhao 
Acked-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso

ipvs: properly update the overload flag on dest edit

2026-08-10T18:14:54+00:00

The upper/lower connection thresholds for dest can be changed,
so use ip_vs_dest_update_overload() to properly update the
dest overload flag.

The thresholds were not limited, fit them in the 0 .. INT_MAX
range as already done in ipvsadm.

As the thresholds are also read when connections are created
and expired, use WRITE_ONCE/READ_ONCE to access them.

As the lower threshold is optional, use (u - (u >> 2)) to
calculate the 75% default value based on the upper threshold
by preserving the integer rounding, as suggested by Yizhou Zhao.

Trigger flag update when totalconns reaches one of the
thresholds and use dst_lock to serialize the updating.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Julian Anastasov 
Signed-off-by: Yizhou Zhao 
Signed-off-by: Pablo Neira Ayuso

ipvs: add totalconns for dest

2026-08-10T18:14:20+00:00

Replace the inactconns dest counter with totalconns, now
inactconns can be obtained from totalconns - activeconns.
This reduces the atomic inc/dec ops for TCP/SCTP from
6 to 4 if the connection is established and then closed.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Julian Anastasov 
Signed-off-by: Yizhou Zhao 
Signed-off-by: Pablo Neira Ayuso

sctp: validate cookie AUTH state before use

2026-08-07T22:02:32+00:00

When cookie authentication is disabled, COOKIE_ECHO restores fixed-size
AUTH fields directly from peer-controlled cookie bytes.  A forged RANDOM
length, HMAC list, or CHUNKS list can then reach association consumers
with lengths or identifiers that were never validated against the local
backing arrays.

A forged RANDOM length can cause out-of-bounds reads during key-vector
construction.  A forged HMAC identifier also caused a 32-byte write past
a zero-length AUTH chunk, providing a primitive for a local privilege
escalation chain.

Validate the cookie's RANDOM, HMACS, and CHUNKS parameters at the cookie
trust boundary before copying them into the association.  Reject invalid
types, malformed lengths, unsupported HMAC identifiers, HMAC lists
without SHA1, and forbidden chunk ids.

Fixes: bbd0d59809f9 ("[SCTP]: Implement the receive and verification of AUTH chunk")
Fixes: 1f485649f529 ("[SCTP]: Implement SCTP-AUTH internals")
Signed-off-by: Jérémy Jean 
Acked-by: Xin Long 
Link: https://patch.msgid.link/20260804200042.2412009-1-Jeremy.Jean@oss.cyber.gouv.fr
Signed-off-by: Jakub Kicinski

net/sched: reject overly deep qdisc hierarchies

2026-08-06T13:24:44+00:00

Deep qdisc hierarchies can lead to excessive recursion in qdisc tree
walkers and exhaust the kernel stack. The existing loop check does not
cover the create-and-graft path, so a hierarchy can still be extended by
creating a new child qdisc below an already deep parent.

Store the hierarchy depth in struct Qdisc and update it when qdiscs are
grafted. Reject new child qdiscs once the parent is already at the maximum
allowed depth.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Suggested-by: Jamal Hadi Salim 
Reported-by: Vega 
Assisted-by: Codex:gpt-5.4
Signed-off-by: Zijie Huang 
Signed-off-by: Ren Wei 
Reviewed-by: Victor Nogueira 
Link: https://patch.msgid.link/1e9ab39597423fd5d13cfaaf52279b8ee3d9fc3c.1785434373.git.milkory@outlook.com
Acked-by: Jamal Hadi Salim 
Signed-off-by: Paolo Abeni

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf

2026-08-05T23:23:34+00:00

Partial pull of the nf-26-07-31 tag

Pablo says:

====================
The following patchset contains Netfilter/IPVS fixes net, this
includes fixes for ebtables nflog target, ipset hash type,
IPVS kthread estimator

1) Prevent IPVS kthread estimator from draining the est_temp_list
   when netns is being dismantled. From Zhiling Zou.

2) Missing module nflog refcount bump from ebtables nflog target from
   .checkentry path. Similar dependency exists already in xt_NFLOG and
   nft_log. From Chengfeng Ye.

3) Use RCU to fix ipset bookkeeping of cidr values on weakly-ordered
   architectures. From Jozsef Kadlecsik.

4) Use atomic64_t for set->ext_size in ipset to fix parallel inserts
   and deletes racing on updating it. From Jozsef Kadlecsik.

5) Add small wrappers for hash and bucket size to prepare the update
   of ipset hash set types to rhashtable, from Florian Westphal.

6) Add mtype_del_cidr_all() and use it to prepare the migration of
   ipset hash types to rhashtable. From Florian Westphal.

7) Replace existing ipset call_rcu() based destruction with rcu_work
   api also to ease the transition to rhashtable. Also from Florian.

8) Avoid reading the IPv4 ihl field multiple times to prevent local
   attacker to cause out-of-bounds write in ip_vs_nat_icmp(), from
   Julian Anastasov.

9) Restore the checksum validations that could be needed by the IPVS
   FORWARD hook. Also from Julian.
====================

Link: https://patch.msgid.link/20260731151806.849724-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski