net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled
Summary
| CVE | CVE-2026-23381 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-03-25 11:16:38 UTC |
| Updated | 2026-04-18 09:16:22 UTC |
| 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. |
Risk And Classification
EPSS: 0.000320000 probability, percentile 0.090980000 (date 2026-04-18)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected ed842faeb2bd49256f00485402f3113205f91d30 a9d712ccfeef737c0e700a4b5b98f310e07b6b60 git | Not specified |
| CNA | Linux | Linux | affected ed842faeb2bd49256f00485402f3113205f91d30 a5c56e65b685360dd3f2278aeff8c21061feb665 git | Not specified |
| CNA | Linux | Linux | affected ed842faeb2bd49256f00485402f3113205f91d30 7a894eb5de246d79f13105c55a67381039a24d44 git | Not specified |
| CNA | Linux | Linux | affected ed842faeb2bd49256f00485402f3113205f91d30 a12cdaa3375f0bd3c8f4e564be7c143529abfe5b git | Not specified |
| CNA | Linux | Linux | affected ed842faeb2bd49256f00485402f3113205f91d30 aa73deb3b6b730ec280d45b3f423bfa9e17bc122 git | Not specified |
| CNA | Linux | Linux | affected ed842faeb2bd49256f00485402f3113205f91d30 33dec6f10777d5a8f71c0a200f690da5ae3c2e55 git | Not specified |
| CNA | Linux | Linux | affected ed842faeb2bd49256f00485402f3113205f91d30 20ef5c25422f97dd09d751e5ae6c18406cdc78e6 git | Not specified |
| CNA | Linux | Linux | affected ed842faeb2bd49256f00485402f3113205f91d30 e5e890630533bdc15b26a34bb8e7ef539bdf1322 git | Not specified |
| CNA | Linux | Linux | affected 4.15 | Not specified |
| CNA | Linux | Linux | unaffected 4.15 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.253 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.203 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.167 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.130 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.77 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.17 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.19.7 6.19.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/a5c56e65b685360dd3f2278aeff8c21061feb665 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/20ef5c25422f97dd09d751e5ae6c18406cdc78e6 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/a12cdaa3375f0bd3c8f4e564be7c143529abfe5b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/e5e890630533bdc15b26a34bb8e7ef539bdf1322 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/7a894eb5de246d79f13105c55a67381039a24d44 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/33dec6f10777d5a8f71c0a200f690da5ae3c2e55 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/a9d712ccfeef737c0e700a4b5b98f310e07b6b60 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/aa73deb3b6b730ec280d45b3f423bfa9e17bc122 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.