{"id":"CVE-2026-46111","state":"PUBLISHED","title":"Bluetooth: hci_conn: fix potential UAF in create_big_sync","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_conn: fix potential UAF in create_big_sync\n\nAdd hci_conn_valid() check in create_big_sync() to detect stale\nconnections before proceeding with BIG creation. Handle the\nresulting -ECANCELED in create_big_complete() and re-validate the\nconnection under hci_dev_lock() before dereferencing, matching the\npattern used by create_le_conn_complete() and create_pa_complete().\n\nKeep the hci_conn object alive across the async boundary by taking\na reference via hci_conn_get() when queueing create_big_sync(), and\ndropping it in the completion callback. The refcount and the lock\nare complementary: the refcount keeps the object allocated, while\nhci_dev_lock() serializes hci_conn_hash_del()'s list_del_rcu() on\nhdev->conn_hash, as required by hci_conn_del().\n\nhci_conn_put() is called outside hci_dev_unlock() so the final put\n(which resolves to kfree() via bt_link_release) does not run under\nhdev->lock, though the release path would be safe either way.\n\nWithout this, create_big_complete() would unconditionally\ndereference the conn pointer on error, causing a use-after-free\nvia hci_connect_cfm() and hci_conn_del().","publishedAt":"2026-05-28T09:35:19.970Z","updatedAt":"2026-10-19T19:26:43.906Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/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":"eca0ae4aea66914515e5e3098ea051b518ee5316","status":"affected","lessThan":"d41093723e47255d7d74df86e2736711c1b8486e","versionType":"git"},{"version":"eca0ae4aea66914515e5e3098ea051b518ee5316","status":"affected","lessThan":"6823f730bf195fc296d9edd09e2ca94bc1ff5584","versionType":"git"},{"version":"eca0ae4aea66914515e5e3098ea051b518ee5316","status":"affected","lessThan":"1750a2df0eab61dc421a7afae74abdd239a44b85","versionType":"git"},{"version":"eca0ae4aea66914515e5e3098ea051b518ee5316","status":"affected","lessThan":"dc34f8d8240f25dd137dc2758ebbcc75e3779142","versionType":"git"},{"version":"eca0ae4aea66914515e5e3098ea051b518ee5316","status":"affected","lessThan":"f8eaf92c57ad99358dd372580d5ff87623343a72","versionType":"git"},{"version":"eca0ae4aea66914515e5e3098ea051b518ee5316","status":"affected","lessThan":"0beddb0c380bed5f5b8e61ddbe14635bb73d0b41","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_conn.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.0","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.140","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.90","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.32","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.7","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_conn.c"]}],"references":["https://git.kernel.org/stable/c/d41093723e47255d7d74df86e2736711c1b8486e","https://git.kernel.org/stable/c/6823f730bf195fc296d9edd09e2ca94bc1ff5584","https://git.kernel.org/stable/c/1750a2df0eab61dc421a7afae74abdd239a44b85","https://git.kernel.org/stable/c/dc34f8d8240f25dd137dc2758ebbcc75e3779142","https://git.kernel.org/stable/c/f8eaf92c57ad99358dd372580d5ff87623343a72","https://git.kernel.org/stable/c/0beddb0c380bed5f5b8e61ddbe14635bb73d0b41"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/46xxx/CVE-2026-46111.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46111","state":"PUBLISHED","datePublished":"2026-05-28T09:35:19.970Z","dateUpdated":"2026-10-19T19:26:43.906Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.098Z"},"containers":{"cna":{"title":"Bluetooth: hci_conn: fix potential UAF in create_big_sync","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_conn: fix potential UAF in create_big_sync\n\nAdd hci_conn_valid() check in create_big_sync() to detect stale\nconnections before proceeding with BIG creation. Handle the\nresulting -ECANCELED in create_big_complete() and re-validate the\nconnection under hci_dev_lock() before dereferencing, matching the\npattern used by create_le_conn_complete() and create_pa_complete().\n\nKeep the hci_conn object alive across the async boundary by taking\na reference via hci_conn_get() when queueing create_big_sync(), and\ndropping it in the completion callback. The refcount and the lock\nare complementary: the refcount keeps the object allocated, while\nhci_dev_lock() serializes hci_conn_hash_del()'s list_del_rcu() on\nhdev->conn_hash, as required by hci_conn_del().\n\nhci_conn_put() is called outside hci_dev_unlock() so the final put\n(which resolves to kfree() via bt_link_release) does not run under\nhdev->lock, though the release path would be safe either way.\n\nWithout this, create_big_complete() would unconditionally\ndereference the conn pointer on error, causing a use-after-free\nvia hci_connect_cfm() and hci_conn_del()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"eca0ae4aea66914515e5e3098ea051b518ee5316","status":"affected","lessThan":"d41093723e47255d7d74df86e2736711c1b8486e","versionType":"git"},{"version":"eca0ae4aea66914515e5e3098ea051b518ee5316","status":"affected","lessThan":"6823f730bf195fc296d9edd09e2ca94bc1ff5584","versionType":"git"},{"version":"eca0ae4aea66914515e5e3098ea051b518ee5316","status":"affected","lessThan":"1750a2df0eab61dc421a7afae74abdd239a44b85","versionType":"git"},{"version":"eca0ae4aea66914515e5e3098ea051b518ee5316","status":"affected","lessThan":"dc34f8d8240f25dd137dc2758ebbcc75e3779142","versionType":"git"},{"version":"eca0ae4aea66914515e5e3098ea051b518ee5316","status":"affected","lessThan":"f8eaf92c57ad99358dd372580d5ff87623343a72","versionType":"git"},{"version":"eca0ae4aea66914515e5e3098ea051b518ee5316","status":"affected","lessThan":"0beddb0c380bed5f5b8e61ddbe14635bb73d0b41","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_conn.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.0","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.140","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.90","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.32","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.7","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_conn.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/d41093723e47255d7d74df86e2736711c1b8486e"},{"url":"https://git.kernel.org/stable/c/6823f730bf195fc296d9edd09e2ca94bc1ff5584"},{"url":"https://git.kernel.org/stable/c/1750a2df0eab61dc421a7afae74abdd239a44b85"},{"url":"https://git.kernel.org/stable/c/dc34f8d8240f25dd137dc2758ebbcc75e3779142"},{"url":"https://git.kernel.org/stable/c/f8eaf92c57ad99358dd372580d5ff87623343a72"},{"url":"https://git.kernel.org/stable/c/0beddb0c380bed5f5b8e61ddbe14635bb73d0b41"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The UAF is reached only through a local ISO socket connect() syscall (BTPROTO_ISO → iso_connect_bis → hci_connect_bis); BIG broadcast setup is locally initiated and requires no Bluetooth peer or over-the-air frame, so the attacker needs local system access.\nAC:L - This is a use-after-free where the attacker controls both sides of the race — initiating the async create_big work via connect() and freeing the conn (e.g., closing the socket) — and can retry at will, so the condition is within attacker control.\nPR:L - Creating and connecting an ISO socket requires no capability check (iso_sock_create/bt_sock_create perform none), so any unprivileged local user can reach the path on systems where the ISO/BIS feature is enabled.\nUI:N - The attacker performs all steps (open socket, connect, race a teardown); no victim interaction is required.\nS:U - The use-after-free is contained within the kernel's own memory/security authority and does not cross into another security boundary such as a VM or IOMMU domain.\nC:H - A UAF of the hci_conn object gives the attacker control over the freed object's contents, enabling kernel-memory disclosure (e.g., leaking pointers/data placed in the reclaimed allocation).\nI:H - The freed hci_conn is dereferenced and written via hci_connect_cfm() and hci_conn_del() (including list_del_rcu on conn_hash), so heap grooming of the freed slab yields an arbitrary-write/control-flow primitive.\nA:H - Dereferencing and deleting a freed hci_conn reliably causes memory corruption leading to a kernel oops/panic."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-19T16:28:01.615Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.6.140"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.12.90"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.18.32"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"7.0.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-46111","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:19:42.422242Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:26:43.906Z"}}]}}}