{"id":"CVE-2026-90408","state":"PUBLISHED","title":"wifi: ath12k: fix overreads in ath12k_wmi_process_csa_switch_count_event()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: ath12k: fix overreads in ath12k_wmi_process_csa_switch_count_event()\n\nThere is no policy entry for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT, so\nthe parse infrastructure does not enforce a minimum length for the event\nstruct. Additionally, the num_vdevs field is taken directly from firmware\nand used as a loop bound over the vdev_ids array without checking that it\nfits within the TLV payload. Either condition can cause an out-of-bounds\nread.\n\nAdd a TLV policy entry for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT so\nthe parse infrastructure enforces a minimum length for the fixed-size event\nstruct. Add a helper ath12k_wmi_tlv_data_len() to recover the payload\nlength of a parsed TLV from the header preceding its data pointer. Use it\nin ath12k_wmi_process_csa_switch_count_event() to bound num_vdevs before\nthe loop.\n\nCompile tested only.","publishedAt":"2026-09-17T16:09:36.089Z","updatedAt":"2026-10-21T12:51:31.378Z","severity":{"score":7.7,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d889913205cf7ebda905b1e62c5867ed4e39f6c2","status":"affected","lessThan":"d4aec20f3a84634171c139ab2e02bb2e5a5c756b","versionType":"git"},{"version":"d889913205cf7ebda905b1e62c5867ed4e39f6c2","status":"affected","lessThan":"24f7cdabea9f7ab95dbd6d8bc9ac6ec48d96a7e5","versionType":"git"},{"version":"d889913205cf7ebda905b1e62c5867ed4e39f6c2","status":"affected","lessThan":"23bed4ef132c55c9016f0c6122c8b8ba2efa2353","versionType":"git"},{"version":"d889913205cf7ebda905b1e62c5867ed4e39f6c2","status":"affected","lessThan":"bf97c9d5123859a07848462539153176db029f3a","versionType":"git"},{"version":"d889913205cf7ebda905b1e62c5867ed4e39f6c2","status":"affected","lessThan":"878654eb78c6aa0ff585baf1376567c775ca28ec","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/ath/ath12k/wmi.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.3","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/ath/ath12k/wmi.c"]}],"references":["https://git.kernel.org/stable/c/d4aec20f3a84634171c139ab2e02bb2e5a5c756b","https://git.kernel.org/stable/c/24f7cdabea9f7ab95dbd6d8bc9ac6ec48d96a7e5","https://git.kernel.org/stable/c/23bed4ef132c55c9016f0c6122c8b8ba2efa2353","https://git.kernel.org/stable/c/bf97c9d5123859a07848462539153176db029f3a","https://git.kernel.org/stable/c/878654eb78c6aa0ff585baf1376567c775ca28ec"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/90xxx/CVE-2026-90408.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90408","state":"PUBLISHED","datePublished":"2026-09-17T16:09:36.089Z","dateUpdated":"2026-10-21T12:51:31.378Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.812Z"},"containers":{"cna":{"title":"wifi: ath12k: fix overreads in ath12k_wmi_process_csa_switch_count_event()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: ath12k: fix overreads in ath12k_wmi_process_csa_switch_count_event()\n\nThere is no policy entry for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT, so\nthe parse infrastructure does not enforce a minimum length for the event\nstruct. Additionally, the num_vdevs field is taken directly from firmware\nand used as a loop bound over the vdev_ids array without checking that it\nfits within the TLV payload. Either condition can cause an out-of-bounds\nread.\n\nAdd a TLV policy entry for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT so\nthe parse infrastructure enforces a minimum length for the fixed-size event\nstruct. Add a helper ath12k_wmi_tlv_data_len() to recover the payload\nlength of a parsed TLV from the header preceding its data pointer. Use it\nin ath12k_wmi_process_csa_switch_count_event() to bound num_vdevs before\nthe loop.\n\nCompile tested only."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d889913205cf7ebda905b1e62c5867ed4e39f6c2","status":"affected","lessThan":"d4aec20f3a84634171c139ab2e02bb2e5a5c756b","versionType":"git"},{"version":"d889913205cf7ebda905b1e62c5867ed4e39f6c2","status":"affected","lessThan":"24f7cdabea9f7ab95dbd6d8bc9ac6ec48d96a7e5","versionType":"git"},{"version":"d889913205cf7ebda905b1e62c5867ed4e39f6c2","status":"affected","lessThan":"23bed4ef132c55c9016f0c6122c8b8ba2efa2353","versionType":"git"},{"version":"d889913205cf7ebda905b1e62c5867ed4e39f6c2","status":"affected","lessThan":"bf97c9d5123859a07848462539153176db029f3a","versionType":"git"},{"version":"d889913205cf7ebda905b1e62c5867ed4e39f6c2","status":"affected","lessThan":"878654eb78c6aa0ff585baf1376567c775ca28ec","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/ath/ath12k/wmi.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.3","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/ath/ath12k/wmi.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/d4aec20f3a84634171c139ab2e02bb2e5a5c756b"},{"url":"https://git.kernel.org/stable/c/24f7cdabea9f7ab95dbd6d8bc9ac6ec48d96a7e5"},{"url":"https://git.kernel.org/stable/c/23bed4ef132c55c9016f0c6122c8b8ba2efa2353"},{"url":"https://git.kernel.org/stable/c/bf97c9d5123859a07848462539153176db029f3a"},{"url":"https://git.kernel.org/stable/c/878654eb78c6aa0ff585baf1376567c775ca28ec"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","baseScore":7.7,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Firmware supplies the malformed bytes in WMI_PDEV_CSA_SWITCH_COUNT_STATUS_EVENTID (num_vdevs and the WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT TLV length) on CE2 → ath12k_ce_recv_process_cb → ath12k_htc_rx_completion_handler → ath12k_wmi_op_rx; 802.11 CSA IEs do not carry those fields, so this is the host-firmware HTC path, not an over-the-air frame parse.\nAC:L - Pre-fix ath12k_wmi_tlv_policies had no min_len for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT, and ath12k_wmi_process_csa_switch_count_event() used firmware le32 num_vdevs as the vdev_ids[] loop bound with no TLV-length check, so a short event TLV or oversized num_vdevs overreads on every such event with no race.\nPR:N - ath12k_wmi_op_rx() dispatches WMI_PDEV_CSA_SWITCH_COUNT_STATUS_EVENTID from the WMI HTC endpoint (ath12k_connect_pdev_htc_service) with no host uid, capability, or authentication check; the Wi-Fi firmware is the sole source of the event.\nUI:N - ath12k_wmi_process_csa_switch_count_event() reads vdev_ids[i] in the num_vdevs loop before the conf->csa_active continue, so a crafted CSA-count WMI event overreads even when the victim never started a channel switch; no mount or other user action is required.\nS:U - The vdev_ids[] overread and any oops remain inside the host kernel ath12k/mac80211 authority; the bug does not cross a VM, IOMMU, or sandbox boundary.\nC:H - Firmware-chosen num_vdevs is an unbounded u32 loop over the WMI_TAG_ARRAY_UINT32 vdev_ids payload (policy min_len 0), so the handler can read far past the CE WMI skb (~2KB); unknown vdev_ids[i] values are also printed by ath12k_warn(), which is an unbounded kernel overread, not a few bytes.\nI:N - The loop only loads vdev_ids[i] and looks them up with ath12k_mac_get_arvif_by_vdev_id(); it does not write out of bounds, and ieee80211_csa_finish() runs only for an already-valid in-CSA arvif rather than as a write primitive from the overread.\nA:H - A huge num_vdevs walks vdev_ids[] off the WMI skb while holding rcu_read_lock(), which can oops/panic on unmapped or KASAN-redzoned heap past the CE buffer and can stall RCU for a 32-bit iteration count, a full kernel availability loss."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-21T12:51:31.378Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}