{"id":"CVE-2026-64255","state":"PUBLISHED","title":"wifi: iwlwifi: mld: validate sta_mask before ffs() in BA session handlers","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: iwlwifi: mld: validate sta_mask before ffs() in BA session handlers\n\nThree BA session handlers use ffs(ba_data->sta_mask) - 1 to derive a\nstation ID without checking that sta_mask is non-zero. When sta_mask is\nzero, ffs() returns 0 and the subtraction wraps to 0xFFFFFFFF, causing\nan out-of-bounds access on fw_id_to_link_sta[].\n\nAdd WARN_ON_ONCE(!ba_data->sta_mask) guards before each ffs() call,\nconsistent with the existing check in iwl_mld_ampdu_rx_start().","publishedAt":"2026-07-24T15:31:22.870Z","updatedAt":"2026-10-19T20:28:16.644Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b","status":"affected","lessThan":"1de92789ce31e46fa7e7d8e89c90b19cdb1c103b","versionType":"git"},{"version":"9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b","status":"affected","lessThan":"fe7f339f63c9dc4ca546ed7ac38ba4bb3a99dcfc","versionType":"git"},{"version":"9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b","status":"affected","lessThan":"f056fc2b927448d37eca6b6cacc3d1b0f67b20d2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/intel/iwlwifi/mld/agg.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.4","versionType":"semver"},{"version":"6.18.38","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.3","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","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/intel/iwlwifi/mld/agg.c"]}],"references":["https://git.kernel.org/stable/c/1de92789ce31e46fa7e7d8e89c90b19cdb1c103b","https://git.kernel.org/stable/c/fe7f339f63c9dc4ca546ed7ac38ba4bb3a99dcfc","https://git.kernel.org/stable/c/f056fc2b927448d37eca6b6cacc3d1b0f67b20d2"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64255.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64255","state":"PUBLISHED","datePublished":"2026-07-24T15:31:22.870Z","dateUpdated":"2026-10-19T20:28:16.644Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.773Z"},"containers":{"cna":{"title":"wifi: iwlwifi: mld: validate sta_mask before ffs() in BA session handlers","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: iwlwifi: mld: validate sta_mask before ffs() in BA session handlers\n\nThree BA session handlers use ffs(ba_data->sta_mask) - 1 to derive a\nstation ID without checking that sta_mask is non-zero. When sta_mask is\nzero, ffs() returns 0 and the subtraction wraps to 0xFFFFFFFF, causing\nan out-of-bounds access on fw_id_to_link_sta[].\n\nAdd WARN_ON_ONCE(!ba_data->sta_mask) guards before each ffs() call,\nconsistent with the existing check in iwl_mld_ampdu_rx_start()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b","status":"affected","lessThan":"1de92789ce31e46fa7e7d8e89c90b19cdb1c103b","versionType":"git"},{"version":"9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b","status":"affected","lessThan":"fe7f339f63c9dc4ca546ed7ac38ba4bb3a99dcfc","versionType":"git"},{"version":"9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b","status":"affected","lessThan":"f056fc2b927448d37eca6b6cacc3d1b0f67b20d2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/intel/iwlwifi/mld/agg.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.4","versionType":"semver"},{"version":"6.18.38","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.3","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","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/intel/iwlwifi/mld/agg.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/1de92789ce31e46fa7e7d8e89c90b19cdb1c103b"},{"url":"https://git.kernel.org/stable/c/fe7f339f63c9dc4ca546ed7ac38ba4bb3a99dcfc"},{"url":"https://git.kernel.org/stable/c/f056fc2b927448d37eca6b6cacc3d1b0f67b20d2"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:A - The vulnerable BA-session handlers are driven by Wi-Fi aggregation, BAR/DELBA traffic, firmware notifications, and timers influenced by a radio peer, requiring Wi-Fi adjacency.\nAC:L - A malicious associated MLO peer can control ADDBA parameters, link-state transitions, aggregation traffic, DELBA delivery, and inactivity timing, allowing the sequence to be triggered repeatedly without an uncontrollable race.\nPR:N - The peer must have an existing mac80211 station relationship, but needs no host account, kernel capability, or administrative privilege; a malicious AP or associated station satisfies this gate.\nUI:N - Once the wireless relationship exists, the peer can trigger the vulnerable sequence entirely through protocol traffic without further victim action.\nS:U - The vulnerable driver and affected kernel memory belong to the same host security authority, with no VM, IOMMU, or other scope boundary crossed.\nC:H - The 0xFFFFFFFF index reads a pointer far outside the 16-entry array and then follows it through additional pointer dereferences, permitting disclosure of arbitrary kernel memory under a groomed layout.\nI:H - A bogus station pointer can reach the PN and mac80211 receive paths, where attacker-controlled PN bytes and station state are written through pointer-derived addresses, potentially enabling kernel memory corruption and control-flow hijacking.\nA:H - The invalid array access or subsequent pointer dereference can fault in NAPI, RX-queue, or timer context, causing a kernel oops or panic and complete system denial of service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:52:07.539Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.4","versionEndExcluding":"6.18.38"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.4","versionEndExcluding":"7.1.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.4","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64255","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:37:57.745113Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","type":"CWE","description":"CWE-125 Out-of-bounds Read"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:28:16.644Z"}}]}}}