{"id":"CVE-2025-40318","state":"PUBLISHED","title":"Bluetooth: hci_sync: fix race in hci_cmd_sync_dequeue_once","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: fix race in hci_cmd_sync_dequeue_once\n\nhci_cmd_sync_dequeue_once() does lookup and then cancel\nthe entry under two separate lock sections. Meanwhile,\nhci_cmd_sync_work() can also delete the same entry,\nleading to double list_del() and \"UAF\".\n\nFix this by holding cmd_sync_work_lock across both\nlookup and cancel, so that the entry cannot be removed\nconcurrently.","publishedAt":"2025-12-08T00:46:45.382Z","updatedAt":"2026-10-15T22:02:43.644Z","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":"f00f36db76eb8fd10d13e80e2590f23b5beaa54d","status":"affected","lessThan":"0a94f7e017438935c09ef833a1aa908ad9875213","versionType":"git"},{"version":"1499f79995c7ee58e3bfeeff75f6d1b37dcda881","status":"affected","lessThan":"932c0a4f77ac13e526fdd5b42914d29c9821d389","versionType":"git"},{"version":"505ea2b295929e7be2b4e1bc86ee31cb7862fb01","status":"affected","lessThan":"ae76cf6c2c842944c6514c57df54d728f1916553","versionType":"git"},{"version":"505ea2b295929e7be2b4e1bc86ee31cb7862fb01","status":"affected","lessThan":"9cd536970192b72257afcdfba0bfc09993e6f19c","versionType":"git"},{"version":"505ea2b295929e7be2b4e1bc86ee31cb7862fb01","status":"affected","lessThan":"09b0cd1297b4dbfe736aeaa0ceeab2265f47f772","versionType":"git"},{"version":"357603f4d396d85fbf0045512efaf1d7f7394ed7","status":"affected","versionType":"git"},{"version":"6.1.120","status":"affected","lessThan":"6.1.159","versionType":"semver"},{"version":"6.6.51","status":"affected","lessThan":"6.6.117","versionType":"semver"},{"version":"6.8.9","status":"affected","lessThan":"6.9","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":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"6.1.159","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.117","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.58","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.17.8","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","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/0a94f7e017438935c09ef833a1aa908ad9875213","https://git.kernel.org/stable/c/932c0a4f77ac13e526fdd5b42914d29c9821d389","https://git.kernel.org/stable/c/ae76cf6c2c842944c6514c57df54d728f1916553","https://git.kernel.org/stable/c/9cd536970192b72257afcdfba0bfc09993e6f19c","https://git.kernel.org/stable/c/09b0cd1297b4dbfe736aeaa0ceeab2265f47f772"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/40xxx/CVE-2025-40318.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-40318","state":"PUBLISHED","datePublished":"2025-12-08T00:46:45.382Z","dateUpdated":"2026-10-15T22:02:43.644Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T07:20:57.186Z"},"containers":{"cna":{"title":"Bluetooth: hci_sync: fix race in hci_cmd_sync_dequeue_once","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: fix race in hci_cmd_sync_dequeue_once\n\nhci_cmd_sync_dequeue_once() does lookup and then cancel\nthe entry under two separate lock sections. Meanwhile,\nhci_cmd_sync_work() can also delete the same entry,\nleading to double list_del() and \"UAF\".\n\nFix this by holding cmd_sync_work_lock across both\nlookup and cancel, so that the entry cannot be removed\nconcurrently."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f00f36db76eb8fd10d13e80e2590f23b5beaa54d","status":"affected","lessThan":"0a94f7e017438935c09ef833a1aa908ad9875213","versionType":"git"},{"version":"1499f79995c7ee58e3bfeeff75f6d1b37dcda881","status":"affected","lessThan":"932c0a4f77ac13e526fdd5b42914d29c9821d389","versionType":"git"},{"version":"505ea2b295929e7be2b4e1bc86ee31cb7862fb01","status":"affected","lessThan":"ae76cf6c2c842944c6514c57df54d728f1916553","versionType":"git"},{"version":"505ea2b295929e7be2b4e1bc86ee31cb7862fb01","status":"affected","lessThan":"9cd536970192b72257afcdfba0bfc09993e6f19c","versionType":"git"},{"version":"505ea2b295929e7be2b4e1bc86ee31cb7862fb01","status":"affected","lessThan":"09b0cd1297b4dbfe736aeaa0ceeab2265f47f772","versionType":"git"},{"version":"357603f4d396d85fbf0045512efaf1d7f7394ed7","status":"affected","versionType":"git"},{"version":"6.1.120","status":"affected","lessThan":"6.1.159","versionType":"semver"},{"version":"6.6.51","status":"affected","lessThan":"6.6.117","versionType":"semver"},{"version":"6.8.9","status":"affected","lessThan":"6.9","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":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"6.1.159","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.117","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.58","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.17.8","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","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/0a94f7e017438935c09ef833a1aa908ad9875213"},{"url":"https://git.kernel.org/stable/c/932c0a4f77ac13e526fdd5b42914d29c9821d389"},{"url":"https://git.kernel.org/stable/c/ae76cf6c2c842944c6514c57df54d728f1916553"},{"url":"https://git.kernel.org/stable/c/9cd536970192b72257afcdfba0bfc09993e6f19c"},{"url":"https://git.kernel.org/stable/c/09b0cd1297b4dbfe736aeaa0ceeab2265f47f772"}],"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 flaw is in the Bluetooth HCI command-sync queue, and the create-connection entries it manages are queued and aborted in response to LE/ACL link events from a peer in radio range (advertising reports driving `check_pending_le_conn()`, and `le_conn_timeout` when the peer stops responding). An attacker within Bluetooth range can drive both the queue and cancel sides without any local access.\nAC:L - The attacker controls both sides of the race — repeatedly forcing connection attempts and aborts cycles `hci_cancel_connect_sync()` against the `cmd_sync_work` kthread draining the same list entry, and the attempt can be retried without limit. The window sits between two lock acquisitions in the same function with the worker on a separate CPU, making it readily hit on SMP.\nPR:N - The adjacent attacker holds no credentials on the target: the LE create-connection queue/cancel cycle happens entirely before pairing or authentication completes. Even on the purely local path only an unprivileged AF_BLUETOOTH socket is needed, since `l2cap_sock_create()` gates only SOCK_RAW behind CAP_NET_RAW.\nUI:N - Background LE auto-connect and connection-timeout handling proceed autonomously in kernel workqueues with no victim action. No file must be opened, device mounted, or prompt accepted.\nS:U - The corruption is confined to kernel heap objects managed by the same kernel security authority; there is no VM, IOMMU, or sandbox boundary crossed. Impact is standard in-kernel compromise.\nC:H - The use-after-free reads `entry->destroy` and `entry->data` out of a freed kmalloc-64 object and dereferences them, and the resulting hijacked call plus double-`list_del` write primitive can be leveraged into arbitrary kernel memory disclosure. Freed-slab reads alone already expose adjacent kernel heap contents.\nI:H - `_hci_cmd_sync_cancel_entry()` calls a function pointer read from freed memory and then performs a double `list_del()` that writes attacker-groomable pointers to attacker-groomable addresses, plus a double `kfree()`. That combination is a direct control-flow-hijack and arbitrary-write path to full kernel code execution.\nA:H - Without successful grooming the same code path dereferences LIST_POISON or freed slab contents, producing a `list_del corruption` BUG, GPF, or panic. The double free additionally corrupts the slab allocator, crashing the system."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:09:29.032Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.120","versionEndExcluding":"6.1.159"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.51","versionEndExcluding":"6.6.117"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.12.58"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.17.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.18"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8.9"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2025-40318","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-15T21:59:09.036526Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T22:02:43.644Z"}}]}}}