{"id":"CVE-2026-63974","state":"PUBLISHED","title":"Bluetooth: hci_sync: Set HCI_CMD_DRAIN_WORKQUEUE during device close","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: Set HCI_CMD_DRAIN_WORKQUEUE during device close\n\nSince hci_dev_close_sync() can now be called during the reset path, we\nshould also set HCI_CMD_DRAIN_WORKQUEUE. This avoids queuing timeouts\nwhile the hdev workqueue is being drained.","publishedAt":"2026-07-19T14:55:59.994Z","updatedAt":"2026-10-30T12:27:25.652Z","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":"877afadad2dce8aae1f2aad8ce47e072d4f6165e","status":"affected","lessThan":"ccf07dfb9d7d1e2c7a1eeb782f90d9b614ebba9c","versionType":"git"},{"version":"877afadad2dce8aae1f2aad8ce47e072d4f6165e","status":"affected","lessThan":"7b81c1378b79c3143ca3fdb3d18ac0f01cbabb21","versionType":"git"},{"version":"877afadad2dce8aae1f2aad8ce47e072d4f6165e","status":"affected","lessThan":"9cebe4680bb9a72f80c6541eb24af06db7a1fbc9","versionType":"git"},{"version":"877afadad2dce8aae1f2aad8ce47e072d4f6165e","status":"affected","lessThan":"47330cc875b36a1cf7b3543cb2cf90a7c603ce0e","versionType":"git"},{"version":"877afadad2dce8aae1f2aad8ce47e072d4f6165e","status":"affected","lessThan":"60bceb9a4c693e68cc90ba4b2dfb9e000e8638ff","versionType":"git"},{"version":"877afadad2dce8aae1f2aad8ce47e072d4f6165e","status":"affected","lessThan":"525daaea459fc215f432de1b8debbd9144bf97b0","versionType":"git"},{"version":"4bf367fa1fefabdf14938d0ac9ed60020389112e","status":"affected","versionType":"git"},{"version":"3b382555706558f5c0587862b6dc03e96a252bba","status":"affected","versionType":"git"},{"version":"5.18.18","status":"affected","lessThan":"5.19","versionType":"semver"},{"version":"5.19.2","status":"affected","lessThan":"5.20","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_sync.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.0","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.93","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.35","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.12","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_sync.c"]}],"references":["https://git.kernel.org/stable/c/ccf07dfb9d7d1e2c7a1eeb782f90d9b614ebba9c","https://git.kernel.org/stable/c/7b81c1378b79c3143ca3fdb3d18ac0f01cbabb21","https://git.kernel.org/stable/c/9cebe4680bb9a72f80c6541eb24af06db7a1fbc9","https://git.kernel.org/stable/c/47330cc875b36a1cf7b3543cb2cf90a7c603ce0e","https://git.kernel.org/stable/c/60bceb9a4c693e68cc90ba4b2dfb9e000e8638ff","https://git.kernel.org/stable/c/525daaea459fc215f432de1b8debbd9144bf97b0"],"weaknesses":["CWE-400"],"ingestedAt":"2026-10-30T12:46:06.359Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/63xxx/CVE-2026-63974.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63974","state":"PUBLISHED","datePublished":"2026-07-19T14:55:59.994Z","dateUpdated":"2026-10-30T12:27:25.652Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.024Z"},"containers":{"cna":{"title":"Bluetooth: hci_sync: Set HCI_CMD_DRAIN_WORKQUEUE during device close","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: Set HCI_CMD_DRAIN_WORKQUEUE during device close\n\nSince hci_dev_close_sync() can now be called during the reset path, we\nshould also set HCI_CMD_DRAIN_WORKQUEUE. This avoids queuing timeouts\nwhile the hdev workqueue is being drained."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"877afadad2dce8aae1f2aad8ce47e072d4f6165e","status":"affected","lessThan":"ccf07dfb9d7d1e2c7a1eeb782f90d9b614ebba9c","versionType":"git"},{"version":"877afadad2dce8aae1f2aad8ce47e072d4f6165e","status":"affected","lessThan":"7b81c1378b79c3143ca3fdb3d18ac0f01cbabb21","versionType":"git"},{"version":"877afadad2dce8aae1f2aad8ce47e072d4f6165e","status":"affected","lessThan":"9cebe4680bb9a72f80c6541eb24af06db7a1fbc9","versionType":"git"},{"version":"877afadad2dce8aae1f2aad8ce47e072d4f6165e","status":"affected","lessThan":"47330cc875b36a1cf7b3543cb2cf90a7c603ce0e","versionType":"git"},{"version":"877afadad2dce8aae1f2aad8ce47e072d4f6165e","status":"affected","lessThan":"60bceb9a4c693e68cc90ba4b2dfb9e000e8638ff","versionType":"git"},{"version":"877afadad2dce8aae1f2aad8ce47e072d4f6165e","status":"affected","lessThan":"525daaea459fc215f432de1b8debbd9144bf97b0","versionType":"git"},{"version":"4bf367fa1fefabdf14938d0ac9ed60020389112e","status":"affected","versionType":"git"},{"version":"3b382555706558f5c0587862b6dc03e96a252bba","status":"affected","versionType":"git"},{"version":"5.18.18","status":"affected","lessThan":"5.19","versionType":"semver"},{"version":"5.19.2","status":"affected","lessThan":"5.20","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_sync.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.0","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.93","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.35","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.12","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_sync.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/ccf07dfb9d7d1e2c7a1eeb782f90d9b614ebba9c"},{"url":"https://git.kernel.org/stable/c/7b81c1378b79c3143ca3fdb3d18ac0f01cbabb21"},{"url":"https://git.kernel.org/stable/c/9cebe4680bb9a72f80c6541eb24af06db7a1fbc9"},{"url":"https://git.kernel.org/stable/c/47330cc875b36a1cf7b3543cb2cf90a7c603ce0e"},{"url":"https://git.kernel.org/stable/c/60bceb9a4c693e68cc90ba4b2dfb9e000e8638ff"},{"url":"https://git.kernel.org/stable/c/525daaea459fc215f432de1b8debbd9144bf97b0"}],"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 - This is a Bluetooth HCI subsystem bug where exploitation requires concurrent HCI controller events from the radio during adapter close/reset; on phones and laptops with Bluetooth enabled in public spaces, a nearby attacker can supply that traffic while the kernel tears down the adapter.\nAC:L - The attacker controls both sides of the race by timing Bluetooth traffic against adapter reset/close or error-recovery teardown, and syzbot reliably reproduced the original workqueue-drain class of this bug.\nPR:N - No local credentials are required on the remote path: a nearby Bluetooth attacker can drive ncmd/cmd timeout recovery that calls hci_dev_do_close() → hci_dev_close_sync(); local CAP_NET_ADMIN ioctl reset is an additional reachable path via user namespaces.\nUI:N - Exploitation does not require the victim to perform a specific action beyond having Bluetooth enabled, which is the default on most mobile and laptop deployments.\nS:U - Impact is confined to kernel Bluetooth/HCI state and does not cross a security boundary such as a VM escape or sandbox breakout.\nC:H - Queueing work onto a draining workqueue corrupts kernel workqueue metadata for cmd_timer/ncmd_timer delayed-work structures, which is memory corruption that could be leveraged for information disclosure during the close/open reset cycle.\nI:H - The workqueue invariant violation leaves delayed-work items in inconsistent states on a persistent hdev->workqueue that is reused after reset, creating a plausible path to control-flow hijack via corrupted work callbacks.\nA:H - Triggering this bug produces a kernel WARNING in __queue_work() (kernel panic on panic_on_warn systems) and can cause drain_workqueue() to spin with repeated reflush attempts, denying Bluetooth availability and potentially hanging the adapter teardown path."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:27:25.652Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.12.93"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.18.35"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"7.0.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"7.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18.18"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-63974","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:34:21.021938Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-400","lang":"en","type":"CWE","description":"CWE-400 Uncontrolled Resource Consumption"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:17:59.582Z"}}]}}}