net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled
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: ? 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.
CVE-2026-23381
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-23381
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "ed842faeb2bd49256f00485402f3113205f91d30",
"lessThan": "a9d712ccfeef737c0e700a4b5b98f310e07b6b60",
"versionType": "git"
},
{
"status": "affected",
"version": "ed842faeb2bd49256f00485402f3113205f91d30",
"lessThan": "a5c56e65b685360dd3f2278aeff8c21061feb665",
"versionType": "git"
},
{
"status": "affected",
"version": "ed842faeb2bd49256f00485402f3113205f91d30",
"lessThan": "7a894eb5de246d79f13105c55a67381039a24d44",
"versionType": "git"
},
{
"status": "affected",
"version": "ed842faeb2bd49256f00485402f3113205f91d30",
"lessThan": "a12cdaa3375f0bd3c8f4e564be7c143529abfe5b",
"versionType": "git"
},
{
"status": "affected",
"version": "ed842faeb2bd49256f00485402f3113205f91d30",
"lessThan": "aa73deb3b6b730ec280d45b3f423bfa9e17bc122",
"versionType": "git"
},
{
"status": "affected",
"version": "ed842faeb2bd49256f00485402f3113205f91d30",
"lessThan": "33dec6f10777d5a8f71c0a200f690da5ae3c2e55",
"versionType": "git"
},
{
"status": "affected",
"version": "ed842faeb2bd49256f00485402f3113205f91d30",
"lessThan": "20ef5c25422f97dd09d751e5ae6c18406cdc78e6",
"versionType": "git"
},
{
"status": "affected",
"version": "ed842faeb2bd49256f00485402f3113205f91d30",
"lessThan": "e5e890630533bdc15b26a34bb8e7ef539bdf1322",
"versionType": "git"
}
],
"programFiles": [
"net/bridge/br_device.c",
"net/bridge/br_input.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.253",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.203",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.167",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.130",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.77",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.17",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "6.19.7",
"versionType": "semver",
"lessThanOrEqual": "6.19.*"
},
{
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/bridge/br_device.c",
"net/bridge/br_input.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-23381
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #27243 · Revision 1
- Added to Heist Feed
- Publisher date