{"id":"CVE-2026-74366","summary":"wifi: ath12k: fix NULL deref in change_sta_links for unready link","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: ath12k: fix NULL deref in change_sta_links for unready link\n\n_ieee80211_set_active_links() calls _ieee80211_link_use_channel() for\neach newly-added link and WARN_ON_ONCE()s if it fails. The call uses\nassign_on_failure=true, which allows mac80211 to continue despite\ndriver failures, but when a mac80211-level channel validation fails\n(e.g., combinations check, DFS, or no available radio),\ndrv_assign_vif_chanctx() is never reached. Since ath12k_mac_vdev_create()\nis only called from that path, arvif-\u003eis_created remains false and\narvif-\u003ear remains NULL for the failed link.\n\nThe subsequent drv_change_sta_links() call reaches\nath12k_mac_op_change_sta_links(), which allocates an arsta and sets\nahsta-\u003elinks_map |= BIT(link_id) for the broken link before checking\nwhether the link is ready. When the vdev was never created, only\nstation_add() is skipped, but the link remains in links_map.\n\nAny subsequent operation iterating links_map and dereferencing arvif-\u003ear\nwithout a NULL check will crash. Two observed examples are NULL deref in\nath12k_mac_ml_station_remove() on disconnect and in ath12k_mac_op_set_key()\nwhen wpa_supplicant installs PTK keys.\n\n  BUG: Unable to handle kernel NULL pointer dereference at 0x00000000\n  pc : ath12k_mac_station_post_remove+0x40/0xe8 [ath12k]\n  Call trace:\n   ath12k_mac_station_post_remove+0x40/0xe8 [ath12k]\n   ath12k_mac_op_sta_state+0xb60/0x1720 [ath12k]\n   drv_sta_state+0x100/0xbd8 [mac80211]\n   __sta_info_destroy_part2+0x148/0x178 [mac80211]\n   ieee80211_set_disassoc+0x500/0x678 [mac80211]\n\n  BUG: Unable to handle kernel NULL pointer dereference at 0x00000000\n  pc : ath12k_mac_op_set_key+0x1f8/0x2c0 [ath12k]\n  Call trace:\n   ath12k_mac_op_set_key+0x1f8/0x2c0 [ath12k]\n   drv_set_key+0x70/0x100 [mac80211]\n   ieee80211_key_enable_hw_accel+0x78/0x260 [mac80211]\n   ieee80211_add_key+0x16c/0x2ac [mac80211]\n   nl80211_new_key+0x138/0x280 [cfg80211]\n\nFix this by checking arvif-\u003eis_created before calling\nath12k_mac_alloc_assign_link_sta(). This prevents the broken link from\nentering links_map, so all subsequent operations iterating the bitmap\nare protected. The reliability of arvif-\u003eis_created across all error\npaths is ensured by the preceding patch.\n\nTested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3","modified":"2026-08-18T03:31:14.493547936Z","published":"2026-08-15T05:58:48.264Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74366.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/47809a7c8348bc4a332ccc26a37c7145a5f609f8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5f5be2aa3b6d730c51dd4f8b432f2ad72823e63f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cfcea221db933295bf2cd75a7f80d441c7a51e28"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74366.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74366"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"a27fa6148dacc79451e523c2694bc0a673b1be05"},{"fixed":"cfcea221db933295bf2cd75a7f80d441c7a51e28"},{"fixed":"5f5be2aa3b6d730c51dd4f8b432f2ad72823e63f"},{"fixed":"47809a7c8348bc4a332ccc26a37c7145a5f609f8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74366.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.14.0"},{"fixed":"6.18.40"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74366.json"}}],"schema_version":"1.9.0"}