In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: fix NULL deref in mesh_matches_local()
mesh_matches_local() unconditionally dereferences ie->mesh_config to
compare mesh configuration parameters. When called from
mesh_rx_csa_frame(), the parsed action-frame elements may not contain a
Mesh Configuration IE, leaving ie->mesh_config NULL and triggering a
kernel NULL pointer dereference.
The other two callers are already safe:
- ieee80211_mesh_rx_bcn_presp() checks !elems->mesh_config before
calling mesh_matches_local()
- mesh_plink_get_event() is only reached through
mesh_process_plink_frame(), which checks !elems->mesh_config, too
mesh_rx_csa_frame() is the only caller that passes raw parsed elements
to mesh_matches_local() without guarding mesh_config. An adjacent
attacker can exploit this by sending a crafted CSA action frame that
includes a valid Mesh ID IE but omits the Mesh Configuration IE,
crashing the kernel.
The captured crash log:
Oops: general protection fault, probably for non-canonical address ...
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
Workqueue: events_unbound cfg80211_wiphy_work
[...]
Call Trace:
<TASK>
? __pfx_mesh_matches_local (net/mac80211/mesh.c:65)
ieee80211_mesh_rx_queued_mgmt (net/mac80211/mesh.c:1686)
[...]
ieee80211_iface_work (net/mac80211/iface.c:1754 net/mac80211/iface.c:1802)
[...]
cfg80211_wiphy_work (net/wireless/core.c:426)
process_one_work (net/kernel/workqueue.c:3280)
? assign_work (net/kernel/workqueue.c:1219)
worker_thread (net/kernel/workqueue.c:3352)
? __pfx_worker_thread (net/kernel/workqueue.c:3385)
kthread (net/kernel/kthread.c:436)
[...]
ret_from_fork_asm (net/arch/x86/entry/entry_64.S:255)
</TASK>
This patch adds a NULL check for ie->mesh_config at the top of
mesh_matches_local() to return false early when the Mesh Configuration
IE is absent.
Click to expand
{
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-23396",
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"dateUpdated": "2026-03-26T10:22:49.287Z",
"dateReserved": "2026-01-13T15:37:46.011Z",
"datePublished": "2026-03-26T10:22:49.287Z",
"state": "PUBLISHED"
},
"containers": {
"cna": {
"providerMetadata": {
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux",
"dateUpdated": "2026-03-26T10:22:49.287Z"
},
"title": "wifi: mac80211: fix NULL deref in mesh_matches_local()",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mac80211: fix NULL deref in mesh_matches_local()\n\nmesh_matches_local() unconditionally dereferences ie->mesh_config to\ncompare mesh configuration parameters. When called from\nmesh_rx_csa_frame(), the parsed action-frame elements may not contain a\nMesh Configuration IE, leaving ie->mesh_config NULL and triggering a\nkernel NULL pointer dereference.\n\nThe other two callers are already safe:\n - ieee80211_mesh_rx_bcn_presp() checks !elems->mesh_config before\n calling mesh_matches_local()\n - mesh_plink_get_event() is only reached through\n mesh_process_plink_frame(), which checks !elems->mesh_config, too\n\nmesh_rx_csa_frame() is the only caller that passes raw parsed elements\nto mesh_matches_local() without guarding mesh_config. An adjacent\nattacker can exploit this by sending a crafted CSA action frame that\nincludes a valid Mesh ID IE but omits the Mesh Configuration IE,\ncrashing the kernel.\n\nThe captured crash log:\n\nOops: general protection fault, probably for non-canonical address ...\nKASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\nWorkqueue: events_unbound cfg80211_wiphy_work\n[...]\nCall Trace:\n <TASK>\n ? __pfx_mesh_matches_local (net/mac80211/mesh.c:65)\n ieee80211_mesh_rx_queued_mgmt (net/mac80211/mesh.c:1686)\n [...]\n ieee80211_iface_work (net/mac80211/iface.c:1754 net/mac80211/iface.c:1802)\n [...]\n cfg80211_wiphy_work (net/wireless/core.c:426)\n process_one_work (net/kernel/workqueue.c:3280)\n ? assign_work (net/kernel/workqueue.c:1219)\n worker_thread (net/kernel/workqueue.c:3352)\n ? __pfx_worker_thread (net/kernel/workqueue.c:3385)\n kthread (net/kernel/kthread.c:436)\n [...]\n ret_from_fork_asm (net/arch/x86/entry/entry_64.S:255)\n </TASK>\n\nThis patch adds a NULL check for ie->mesh_config at the top of\nmesh_matches_local() to return false early when the Mesh Configuration\nIE is absent."
}
],
"affected": [
{
"vendor": "Linux",
"product": "Linux",
"programFiles": [
"net/mac80211/mesh.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"defaultStatus": "unaffected",
"versions": [
{
"version": "2e3c8736820bf72a8ad10721c7e31d36d4fa7790",
"status": "affected",
"versionType": "git",
"lessThan": "c1e3f2416fb27c816ce96d747d3e784e31f4d95c"
},
{
"version": "2e3c8736820bf72a8ad10721c7e31d36d4fa7790",
"status": "affected",
"versionType": "git",
"lessThan": "0a4da176ae4b4e075a19c00d3e269cfd5e05a813"
},
{
"version": "2e3c8736820bf72a8ad10721c7e31d36d4fa7790",
"status": "affected",
"versionType": "git",
"lessThan": "a90279e7f7ea0b7e923a1c5ebee9a6b78b6d1004"
},
{
"version": "2e3c8736820bf72a8ad10721c7e31d36d4fa7790",
"status": "affected",
"versionType": "git",
"lessThan": "44699c6cdfce80a0f296b54ae9314461e3e41b3d"
},
{
"version": "2e3c8736820bf72a8ad10721c7e31d36d4fa7790",
"status": "affected",
"versionType": "git",
"lessThan": "7c55a3deaf7eaaafa2546f8de7fed19382a0a116"
},
{
"version": "2e3c8736820bf72a8ad10721c7e31d36d4fa7790",
"status": "affected",
"versionType": "git",
"lessThan": "c73bb9a2d33bf81f6eecaa0f474b6c6dbe9855bd"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"programFiles": [
"net/mac80211/mesh.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"defaultStatus": "affected",
"versions": [
{
"version": "2.6.26",
"status": "affected"
},
{
"version": "0",
"status": "unaffected",
"versionType": "semver",
"lessThan": "2.6.26"
},
{
"version": "6.1.167",
"status": "unaffected",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"version": "6.6.130",
"status": "unaffected",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"version": "6.12.78",
"status": "unaffected",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"version": "6.18.20",
"status": "unaffected",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"version": "6.19.10",
"status": "unaffected",
"versionType": "semver",
"lessThanOrEqual": "6.19.*"
},
{
"version": "7.0-rc5",
"status": "unaffected",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/c1e3f2416fb27c816ce96d747d3e784e31f4d95c"
},
{
"url": "https://git.kernel.org/stable/c/0a4da176ae4b4e075a19c00d3e269cfd5e05a813"
},
{
"url": "https://git.kernel.org/stable/c/a90279e7f7ea0b7e923a1c5ebee9a6b78b6d1004"
},
{
"url": "https://git.kernel.org/stable/c/44699c6cdfce80a0f296b54ae9314461e3e41b3d"
},
{
"url": "https://git.kernel.org/stable/c/7c55a3deaf7eaaafa2546f8de7fed19382a0a116"
},
{
"url": "https://git.kernel.org/stable/c/c73bb9a2d33bf81f6eecaa0f474b6c6dbe9855bd"
}
]
}
}
}