<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/net/ipv6/netfilter, branch v7.2-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2026-06-11T21:33:35+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2026-06-11T21:29:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=dad4d4b92a9b9f0edb8c66deda049da1b62f6089'/>
<id>dad4d4b92a9b9f0edb8c66deda049da1b62f6089</id>
<content type='text'>
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 &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nft_fib: fix stale stack leak via the OIFNAME register</title>
<updated>2026-06-10T16:00:19+00:00</updated>
<author>
<name>Davide Ornaghi</name>
<email>d.ornaghi97@gmail.com</email>
</author>
<published>2026-06-10T10:39:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ab185e0c4fb82dfba6fb86f8271e06f931d9c64c'/>
<id>ab185e0c4fb82dfba6fb86f8271e06f931d9c64c</id>
<content type='text'>
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 &lt;fw@strlen.de&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Davide Ornaghi &lt;d.ornaghi97@gmail.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;fw@strlen.de&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Davide Ornaghi &lt;d.ornaghi97@gmail.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: x_tables: avoid leaking percpu counter pointers</title>
<updated>2026-06-10T15:59:01+00:00</updated>
<author>
<name>Kyle Zeng</name>
<email>kylebot@openai.com</email>
</author>
<published>2026-06-06T08:10:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f7f2fbb0e893a0238dc464f8d8c0f5609bec584f'/>
<id>f7f2fbb0e893a0238dc464f8d8c0f5609bec584f</id>
<content type='text'>
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-&gt;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 &lt;kylebot@openai.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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-&gt;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 &lt;kylebot@openai.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2026-06-04T22:29:04+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2026-06-04T22:26:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8d72997dab65b1e9e3220302e26eaecd9b99c02f'/>
<id>8d72997dab65b1e9e3220302e26eaecd9b99c02f</id>
<content type='text'>
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 &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nft_fib_ipv6: bail out of sibling walk if rt got unlinked</title>
<updated>2026-06-01T11:43:52+00:00</updated>
<author>
<name>Jiayuan Chen</name>
<email>jiayuan.chen@linux.dev</email>
</author>
<published>2026-05-26T02:02:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=36d29ceec32c8206a12dc2810cf65fd394e45baa'/>
<id>36d29ceec32c8206a12dc2810cf65fd394e45baa</id>
<content type='text'>
This was reported by Sashiko [1].

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

fib6_purge_rt() always does WRITE_ONCE(rt-&gt;fib6_nsiblings, 0) before
list_del_rcu(), so readers can use rt-&gt;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 &lt;fw@strlen.de&gt;
Fixes: 1c32b24c234b ("netfilter: nft_fib_ipv6: switch to fib6_lookup")
Signed-off-by: Jiayuan Chen &lt;jiayuan.chen@linux.dev&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This was reported by Sashiko [1].

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

fib6_purge_rt() always does WRITE_ONCE(rt-&gt;fib6_nsiblings, 0) before
list_del_rcu(), so readers can use rt-&gt;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 &lt;fw@strlen.de&gt;
Fixes: 1c32b24c234b ("netfilter: nft_fib_ipv6: switch to fib6_lookup")
Signed-off-by: Jiayuan Chen &lt;jiayuan.chen@linux.dev&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2026-05-28T21:02:21+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2026-05-21T22:02:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d44646fc9eeb423ad50f3043f11f66f491d908a7'/>
<id>d44646fc9eeb423ad50f3043f11f66f491d908a7</id>
<content type='text'>
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 &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: add option for GCOV profiling</title>
<updated>2026-05-24T20:55:47+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2026-05-07T09:34:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=403cec8ab6d002ee26b8345cfd83e58ca3b0606d'/>
<id>403cec8ab6d002ee26b8345cfd83e58ca3b0606d</id>
<content type='text'>
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 &lt;ja@ssi.bg&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;ja@ssi.bg&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: x_tables: disable 32bit compat interface in user namespaces</title>
<updated>2026-05-24T20:55:37+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2026-04-25T13:00:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ec1806a730a1c0b3d68a7f9afe81514fb0dd7991'/>
<id>ec1806a730a1c0b3d68a7f9afe81514fb0dd7991</id>
<content type='text'>
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 &lt;fw@strlen.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;fw@strlen.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nft_fib_ipv6: handle routes via external nexthop</title>
<updated>2026-05-22T10:28:46+00:00</updated>
<author>
<name>Jiayuan Chen</name>
<email>jiayuan.chen@linux.dev</email>
</author>
<published>2026-05-20T02:34:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f81b0c2d281faa93e4c2b7247047922aaf3e4ba6'/>
<id>f81b0c2d281faa93e4c2b7247047922aaf3e4ba6</id>
<content type='text'>
fib6_info has a union:

    union {
        struct list_head fib6_siblings;
        struct list_head nh_list;
    };

Old-style multipath (ip -6 route add ... nexthop ... nexthop ...) uses
fib6_siblings.  External nexthop (ip -6 route add ... nhid N) uses
nh_list, linked into &amp;nh-&gt;f6i_list.

nft_fib6_info_nh_uses_dev() blindly walks &amp;rt-&gt;fib6_siblings, causing
an OOB read past the struct nexthop slab when rt-&gt;nh is set:

  ==================================================================
  BUG: KASAN: slab-out-of-bounds in nft_fib6_eval+0x1362/0x16c0
  Read of size 8 at addr ffff888103a099d0 by task ping/386

  CPU: 2 UID: 0 PID: 386 Comm: ping Not tainted 7.1.0-rc3+ #251 PREEMPT
  Call Trace:
   &lt;IRQ&gt;
   dump_stack_lvl+0x76/0xa0
   print_report+0xd1/0x5f0
   kasan_report+0xe7/0x130
   __asan_report_load8_noabort+0x14/0x30
   nft_fib6_eval+0x1362/0x16c0
   nft_do_chain+0x279/0x18c0
   nft_do_chain_ipv6+0x1a8/0x230
   nf_hook_slow+0xad/0x200
   ipv6_rcv+0x152/0x380
   __netif_receive_skb_one_core+0x118/0x1c0
  ==================================================================

Branch by route shape: when rt-&gt;nh is set, walk via
nexthop_for_each_fib6_nh() (also covers nh groups, which the original
code missed); otherwise walk fib6_siblings, guarded by READ_ONCE() of
rt-&gt;fib6_nsiblings as required by commit 31d7d67ba127 ("ipv6: annotate
data-races around rt-&gt;fib6_nsiblings").

Fixes: 1c32b24c234b ("netfilter: nft_fib_ipv6: switch to fib6_lookup")
Signed-off-by: Jiayuan Chen &lt;jiayuan.chen@linux.dev&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
fib6_info has a union:

    union {
        struct list_head fib6_siblings;
        struct list_head nh_list;
    };

Old-style multipath (ip -6 route add ... nexthop ... nexthop ...) uses
fib6_siblings.  External nexthop (ip -6 route add ... nhid N) uses
nh_list, linked into &amp;nh-&gt;f6i_list.

nft_fib6_info_nh_uses_dev() blindly walks &amp;rt-&gt;fib6_siblings, causing
an OOB read past the struct nexthop slab when rt-&gt;nh is set:

  ==================================================================
  BUG: KASAN: slab-out-of-bounds in nft_fib6_eval+0x1362/0x16c0
  Read of size 8 at addr ffff888103a099d0 by task ping/386

  CPU: 2 UID: 0 PID: 386 Comm: ping Not tainted 7.1.0-rc3+ #251 PREEMPT
  Call Trace:
   &lt;IRQ&gt;
   dump_stack_lvl+0x76/0xa0
   print_report+0xd1/0x5f0
   kasan_report+0xe7/0x130
   __asan_report_load8_noabort+0x14/0x30
   nft_fib6_eval+0x1362/0x16c0
   nft_do_chain+0x279/0x18c0
   nft_do_chain_ipv6+0x1a8/0x230
   nf_hook_slow+0xad/0x200
   ipv6_rcv+0x152/0x380
   __netif_receive_skb_one_core+0x118/0x1c0
  ==================================================================

Branch by route shape: when rt-&gt;nh is set, walk via
nexthop_for_each_fib6_nh() (also covers nh groups, which the original
code missed); otherwise walk fib6_siblings, guarded by READ_ONCE() of
rt-&gt;fib6_nsiblings as required by commit 31d7d67ba127 ("ipv6: annotate
data-races around rt-&gt;fib6_nsiblings").

Fixes: 1c32b24c234b ("netfilter: nft_fib_ipv6: switch to fib6_lookup")
Signed-off-by: Jiayuan Chen &lt;jiayuan.chen@linux.dev&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nft_fib_ipv6: walk fib6_siblings under RCU</title>
<updated>2026-05-22T10:28:46+00:00</updated>
<author>
<name>Jiayuan Chen</name>
<email>jiayuan.chen@linux.dev</email>
</author>
<published>2026-05-20T02:34:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1d001b0a6182b0d2f41a8d687f7522b6f1e94280'/>
<id>1d001b0a6182b0d2f41a8d687f7522b6f1e94280</id>
<content type='text'>
nft_fib6_info_nh_uses_dev() runs from nft_fib6_eval() in softirq under
rcu_read_lock().  fib6_siblings is modified by writers that hold
tb6_lock but do not wait for RCU readers, so the sibling walk should
use list_for_each_entry_rcu(): it adds READ_ONCE() on the -&gt;next
pointer and lets CONFIG_PROVE_RCU_LIST validate the locking.

No functional change for non-debug builds.

Fixes: 1c32b24c234b ("netfilter: nft_fib_ipv6: switch to fib6_lookup")
Signed-off-by: Jiayuan Chen &lt;jiayuan.chen@linux.dev&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
nft_fib6_info_nh_uses_dev() runs from nft_fib6_eval() in softirq under
rcu_read_lock().  fib6_siblings is modified by writers that hold
tb6_lock but do not wait for RCU readers, so the sibling walk should
use list_for_each_entry_rcu(): it adds READ_ONCE() on the -&gt;next
pointer and lets CONFIG_PROVE_RCU_LIST validate the locking.

No functional change for non-debug builds.

Fixes: 1c32b24c234b ("netfilter: nft_fib_ipv6: switch to fib6_lookup")
Signed-off-by: Jiayuan Chen &lt;jiayuan.chen@linux.dev&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
</pre>
</div>
</content>
</entry>
</feed>
