{"id":"CVE-2026-23396","summary":"wifi: mac80211: fix NULL deref in mesh_matches_local()","details":"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-\u003emesh_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-\u003emesh_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-\u003emesh_config before\n    calling mesh_matches_local()\n  - mesh_plink_get_event() is only reached through\n    mesh_process_plink_frame(), which checks !elems-\u003emesh_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 \u003cTASK\u003e\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 \u003c/TASK\u003e\n\nThis patch adds a NULL check for ie-\u003emesh_config at the top of\nmesh_matches_local() to return false early when the Mesh Configuration\nIE is absent.","modified":"2026-04-02T13:12:23.856251Z","published":"2026-03-26T10:22:49.287Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23396.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/0a4da176ae4b4e075a19c00d3e269cfd5e05a813"},{"type":"WEB","url":"https://git.kernel.org/stable/c/44699c6cdfce80a0f296b54ae9314461e3e41b3d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7c55a3deaf7eaaafa2546f8de7fed19382a0a116"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a90279e7f7ea0b7e923a1c5ebee9a6b78b6d1004"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c1e3f2416fb27c816ce96d747d3e784e31f4d95c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c73bb9a2d33bf81f6eecaa0f474b6c6dbe9855bd"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23396.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23396"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"2e3c8736820bf72a8ad10721c7e31d36d4fa7790"},{"fixed":"c1e3f2416fb27c816ce96d747d3e784e31f4d95c"},{"fixed":"0a4da176ae4b4e075a19c00d3e269cfd5e05a813"},{"fixed":"a90279e7f7ea0b7e923a1c5ebee9a6b78b6d1004"},{"fixed":"44699c6cdfce80a0f296b54ae9314461e3e41b3d"},{"fixed":"7c55a3deaf7eaaafa2546f8de7fed19382a0a116"},{"fixed":"c73bb9a2d33bf81f6eecaa0f474b6c6dbe9855bd"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23396.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.26"},{"fixed":"6.1.167"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.130"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.78"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.20"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23396.json"}}],"schema_version":"1.7.5"}