net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled (Linux Linux)

CVE-2026-23381
MEDIUM 5.5

At a glance

Source
NVD
EPSS
EPSS 0.13 % · percentile 2 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

Description

In the Linux kernel, the following vulnerability has been resolved: net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never initialized because inet6_init() exits before ndisc_init() is called which initializes it. Then, if neigh_suppress is enabled and an ICMPv6 Neighbor Discovery packet reaches the bridge, br_do_suppress_nd() will dereference ipv6_stub->nd_tbl which is NULL, passing it to neigh_lookup(). This causes a kernel NULL pointer dereference. BUG: kernel NULL pointer dereference, address: 0000000000000268 Oops: 0000 [#1] PREEMPT SMP NOPTI [...] RIP: 0010:neigh_lookup+0x16/0xe0 [...] Call Trace: <IRQ> ? neigh_lookup+0x16/0xe0 br_do_suppress_nd+0x160/0x290 [bridge] br_handle_frame_finish+0x500/0x620 [bridge] br_handle_frame+0x353/0x440 [bridge] __netif_receive_skb_core.constprop.0+0x298/0x1110 __netif_receive_skb_one_core+0x3d/0xa0 process_backlog+0xa0/0x140 __napi_poll+0x2c/0x170 net_rx_action+0x2c4/0x3a0 handle_softirqs+0xd0/0x270 do_softirq+0x3f/0x60 Fix this by replacing IS_ENABLED(IPV6) call with ipv6_mod_enabled() in the callers. This is in essence disabling NS/NA suppression when IPv6 is disabled.

Weaknesses (CWE)

  • CWE-476 — NULL Pointer Dereference

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected ed842faeb2bd49256f00485402f3113205f91d30 < a9d712ccfeef737c0e700a4b5b98f310e07b6b60 ; affected ed842faeb2bd49256f00485402f3113205f91d30 < a5c56e65b685360dd3f2278aeff8c21061feb665 ; affected ed842faeb2bd49256f00485402f3113205f91d30 < 7a894eb5de246d79f13105c55a67381039a24d44 ; affected ed842faeb2bd49256f00485402f3113205f91d30 < a12cdaa3375f0bd3c8f4e564be7c143529abfe5b ; affected ed842faeb2bd49256f00485402f3113205f91d30 < aa73deb3b6b730ec280d45b3f423bfa9e17bc122 ; affected ed842faeb2bd49256f00485402f3113205f91d30 < 33dec6f10777d5a8f71c0a200f690da5ae3c2e55
Linux · Linuxaffected 4.15 ; unaffected 0 < 4.15 ; unaffected 5.10.253 ≤ 5.10.* ; unaffected 5.15.203 ≤ 5.15.* ; unaffected 6.1.167 ≤ 6.1.* ; unaffected 6.6.130 ≤ 6.6.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD