linux.git/net/ipv6/netfilter, branch v7.2-rc3

netfilter: handle unreadable frags

2026-07-08T13:33:44+00:00

sashiko reports:
 When an skb with unreadable fragments (such as from devmem TCP, where
 skb_frags_readable(skb) returns false) is processed by the u32 module,
 skb_copy_bits() will safely return a negative error code [..]

xt_u32: bail out with hotdrop in this case.
gather_frags: return -1, just as if we had no fragment header.
nfnetlink_queue: restrict to the linear part.
nfnetlink_log: restrict to the linear part.

v2:
 - skb_zerocopy helpers don't copy readable flag, i.e. nfnetlink_queue
 is broken too
 xt_u32 shouldn't return true if hotdrop was set.

Fixes: 65249feb6b3d ("net: add support for skbs with unreadable frags")
Cc: stable@vger.kernel.org
Acked-by: Mina Almasry 
Signed-off-by: Florian Westphal

netfilter: nf_conntrack_reasm: guard mac_header adjustment after IPv6 defrag

2026-07-08T13:22:03+00:00

nf_ct_frag6_reasm() slides the packet head forward to drop the IPv6
fragment header and then unconditionally advances skb->mac_header:

	skb->mac_header += sizeof(struct frag_hdr);

On the NF_INET_LOCAL_OUT defrag path the skb has no link-layer header
yet, so skb->mac_header is still the "not set" sentinel (u16)~0U. Adding
sizeof(struct frag_hdr) wraps it to a small value (0xffff + 8 == 7),
after which skb_mac_header_was_set() wrongly reports a MAC header is
present and skb_mac_header() points into the headroom.

The reassembler has done this unconditional add since it was introduced;
it was harmless while mac_header was a bare pointer, but wrong once
mac_header became a u16 offset whose unset state is the ~0U sentinel
tested by skb_mac_header_was_set(). The sibling net/ipv6/reassembly.c
does the same relocation and does guard the adjustment; mirror the
guard here.

Fixes: 9fb9cbb1082d ("[NETFILTER]: Add nf_conntrack subsystem.")
Cc: stable@vger.kernel.org
Reported-by: Weiming Shi 
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Xiang Mei 
Signed-off-by: Florian Westphal

netfilter: ip6tables: mark malformed IPv6 extension headers for hotdrop

2026-07-03T12:45:21+00:00

The ah, hbh and rt matches check that the fixed extension header is
present, then use the header length field to derive the advertised
extension header length for matching.

For the ah match, add the missing advertised-length check. For hbh
and rt, update the existing advertised-length checks. In all three
cases, set hotdrop to true before returning false when the advertised
extension header length exceeds the available skb data.

Returning false treats the packet as a rule mismatch. Set hotdrop to
true and drop malformed packets so they cannot bypass rules intended
to drop packets with these IPv6 extension headers.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Zhixing Chen 
Signed-off-by: Florian Westphal

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-06-11T21:33:35+00:00

Cross-merge networking fixes after downstream PR (net-7.1-rc8).

Conflicts:

drivers/net/ethernet/wangxun/txgbe/txgbe_aml.c
  f67aead16e85 ("net: txgbe: rework service event handling")
  57d39faed4c9 ("net: txgbe: improve functions of AML 40G devices")

net/rds/info.c
  512db8267b73 ("rds: mark snapshot pages dirty in rds_info_getsockopt()")
  6e94eeb2a2a6 ("rds: convert to getsockopt_iter")

Adjacent changes:

include/net/sock.h
  1ee90b77b727 ("net: guard timestamp cmsgs to real error queue skbs")
  f0de88303d5e ("net: make is_skb_wmem() available to modules")

Signed-off-by: Jakub Kicinski

netfilter: nft_fib: fix stale stack leak via the OIFNAME register

2026-06-10T16:00:19+00:00

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: f6d0cbcf09c5 ("netfilter: nf_tables: add fib expression")
Suggested-by: Florian Westphal 
Cc: stable@vger.kernel.org
Signed-off-by: Davide Ornaghi 
Signed-off-by: Pablo Neira Ayuso

netfilter: x_tables: avoid leaking percpu counter pointers

2026-06-10T15:59:01+00:00

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: 71ae0dff02d7 ("netfilter: xtables: use percpu rule counters")
Signed-off-by: Kyle Zeng 
Signed-off-by: Pablo Neira Ayuso

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-06-04T22:29:04+00:00

Cross-merge networking fixes after downstream PR (net-7.1-rc7).

Silent conflicts:

net/wireless/nl80211.c
  cb9959ab5f99 ("wifi: cfg80211: enforce HE/EHT cap/oper consistency")
  a384ae969902 ("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
  a342c99cb70d ("wifi: iwlwifi: mld: honor BSS_CHANGED_BEACON_ENABLED")
  9bf1b409afc7 ("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
  093305d801fa ("wifi: iwlwifi: pcie: simplify the resume flow if fast resume is not used")
  e2323929a68a ("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
  b38cae85d1c4 ("net: airoha: Fix use-after-free in metadata dst teardown")
  ec6c391bcca7 ("net: airoha: Introduce airoha_gdm_dev struct")

drivers/net/ethernet/microchip/lan743x_main.c
  8173d22b211f ("net: lan743x: permit VLAN-tagged packets up to configured MTU")
  e3c6508a46f5 ("net: lan743x: avoid netdev-based logging before netdev registration")

Signed-off-by: Jakub Kicinski

netfilter: nft_fib_ipv6: bail out of sibling walk if rt got unlinked

2026-06-01T11:43:52+00:00

This was reported by Sashiko [1].

The RCU walk over rt->fib6_siblings can spin forever if rt is unlinked
mid-iteration: rt->fib6_siblings.next still points into the old ring,
so the loop never meets &rt->fib6_siblings as its terminator.

fib6_purge_rt() always does WRITE_ONCE(rt->fib6_nsiblings, 0) before
list_del_rcu(), so readers can use rt->fib6_nsiblings == 0 as the
detach signal. The same pattern is used in fib6_info_uses_dev() and
rt6_nlmsg_size().

[1]: https://sashiko.dev/#/patchset/20260520023411.391233-1-jiayuan.chen%40linux.dev
Suggested-by: Florian Westphal 
Fixes: 1c32b24c234b ("netfilter: nft_fib_ipv6: switch to fib6_lookup")
Signed-off-by: Jiayuan Chen 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-05-28T21:02:21+00:00

Cross-merge networking fixes after downstream PR (net-7.1-rc6).

Conflicts:

drivers/net/phy/air_en8811h.c
  d895767c33781 ("net: phy: air_en8811h: add AN8811HB MCU assert/deassert support")
  dddfadd75197e ("net: phy: Add Airoha phy library for shared code")
  5226bb6634cdf ("net: phy: air_phy_lib: Factorize BuckPBus register accessors")
  e08f0ea6daf2e ("net: phy: Rename Airoha common BuckPBus register accessors")

net/sched/sch_netem.c
  a2f6ed7b4873 ("net/sched: netem: add per-impairment extended statistics")
  9552b11e3eda ("net/sched: fix packet loop on netem when duplicate is on")

Adjacent changes:

drivers/dpll/zl3073x/core.c
  c1224569cef0 ("dpll: zl3073x: make frequency monitor a per-device attribute")
  54e65df8cf18 ("dpll: zl3073x: report FFO as DPLL vs input reference offset")

net/iucv/af_iucv.c
  347fdd4df85f ("af_iucv: convert to getsockopt_iter")
  3589d20a666c ("net/iucv: fix locking in .getsockopt")

Signed-off-by: Jakub Kicinski

netfilter: add option for GCOV profiling

2026-05-24T20:55:47+00:00

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 
Signed-off-by: Florian Westphal