{"id":"CVE-2026-46275","revision":"aaf960103f4345eea7dd39e4a5669f48","records":[{"revision":"aaf960103f4345eea7dd39e4a5669f48","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-46275","aliases":[],"title":"Bluetooth: hci_uart: fix UAFs and race conditions in close and init paths","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_uart: fix UAFs and race conditions in close and init paths\n\nVulnerabilities leading to Use-After-Free (UAF) and Null Pointer\nDereference (NPD) conditions were observed in the lifecycle management\nof hci_uart.\n\nThe primary issue arises because the workqueues (init_ready and\nwrite_work) are only flushed/cancelled if the HCI_UART_PROTO_READY\nflag is set during TTY close. If a hangup occurs before setup completes,\nhci_uart_tty_close() skips the teardown of these workqueues and\nproceeds to free the `hu` struct. When the scheduled work executes\nlater, it blindly dereferences the freed `hu` struct.\n\nFurthermore, several data races and UAFs were identified in the teardown\nsequence:\n1. Calling hci_uart_flush() from hci_uart_close() without effectively\n disabling write_work causes a race condition where both can concurrently\n double-free hu->tx_skb. This happens because protocol timers can\n concurrently invoke hci_uart_tx_wakeup() and requeue write_work.\n2. Calling hci_free_dev(hdev) before hu->proto->close(hu) causes a UAF\n when vendor specific protocol close callbacks dereference hu->hdev.\n3. In the initialization error paths, failing to take the proto_lock\n write lock before clearing PROTO_READY leads to races with active\n readers. Additionally, hci_uart_tty_receive() accesses hu->hdev\n outside the read lock, leading to UAFs if the initialization error\n path frees hdev concurrently.\n\nFix these synchronization and lifecycle issues by:\n1. Re-ordering hci_uart_tty_close() to clear HCI_UART_PROTO_READY first,\n followed immediately by a cancel_work_sync(&hu->write_work). Clearing\n the flag locks out concurrent protocol timers from successfully invoking\n hci_uart_tx_wakeup(), effectively rendering the cancellation permanent\n and preventing the tx_skb double-free.\n2. Note: Clearing PROTO_READY early causes hci_uart_close() to skip\n hu->proto->flush(). This is perfectly safe in the tty_close path\n because hu->proto->close() executes shortly after, which intrinsically\n purges all protocol SKB queues and tears down the state.\n3. Relocating hu->proto->close(hu) strictly prior to hci_free_dev(hdev)\n across all close and error paths to prevent vendor-level UAFs.\n4. Moving the hdev->stat.byte_rx increment in hci_uart_tty_receive()\n inside the proto_lock read-side critical section to safely synchronize\n with device unregistration.\n5. Adding cancel_work_sync(&hu->write_work) to hci_uart_close() to safely\n flush the workqueue before hci_uart_flush() is invoked via the HCI core.\n6. Utilizing cancel_work_sync() instead of disable_work_sync() across\n all paths to prevent permanently breaking user-space retry capabilities.","state":0,"publishedAt":"2026-06-08T14:30:54.232+00:00","modifiedAt":"2026-10-19T19:36:56.765+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"drivers/bluetooth/hci_ldisc.c\"\n ],\n \"versions\": [\n {\n \"version\": \"3b799254cf6f481460719023d7a18f46651e5e7f\",\n \"lessThan\": \"78aad93e938f013d9272fe0ee168f27883afa95c\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3b799254cf6f481460719023d7a18f46651e5e7f\",\n \"lessThan\": \"e2d19969c8d9198ecc3090bcd5312ecd503a3339\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3b799254cf6f481460719023d7a18f46651e5e7f\",\n \"lessThan\": \"c85cff648a2bc92322912db5f1727ad05afae7b6\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3b799254cf6f481460719023d7a18f46651e5e7f\",\n \"lessThan\": \"9d20d48be2c4a071fb015eb09bda2cecd25daf34\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3b799254cf6f481460719023d7a18f46651e5e7f\",\n \"lessThan\": \"81c7a3c22a0f2808cf4ae0b4908f59763b23606d\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3b799254cf6f481460719023d7a18f46651e5e7f\",\n \"lessThan\": \"192cb0f1ca706d9a1bc36ae0ad5f666d1e4fd894\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3b799254cf6f481460719023d7a18f46651e5e7f\",\n \"lessThan\": \"7338031946bd06f6dff149e67b60c4cd083bfea8\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3b799254cf6f481460719023d7a18f46651e5e7f\",\n \"lessThan\": \"c1bb9336ae6b54a5f6a353c4bd4ed9a4307e429b\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"cd27019bc149f20f12ebec943c2b4c775745a5a0\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"aea63181b6fcb6b9ccde1ada9ea51be19c4015af\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"0d234d1135dcd8876de0576dac68efd0a87eef87\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3fe978892ab46efc2f3830d9abc015eff72caaf9\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"0d987e14bebaf0f67ee7dbefaf6165c62cd1d27f\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"4.14.203\",\n \"lessThan\": \"4.15\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"4.19.153\",\n \"lessThan\": \"4.20\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.4.73\",\n \"lessThan\": \"5.5\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.8.17\",\n \"lessThan\": \"5.9\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.9.2\",\n \"lessThan\": \"5.10\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"drivers/bluetooth/hci_ldisc.c\"\n ],\n \"versions\": [\n {\n \"version\": \"5.10\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"5.10\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.258\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.209\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.175\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.142\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.92\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.34\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.0.11\",\n \"lessThanOrEqual\": \"7.0.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.1\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/78aad93e938f013d9272fe0ee168f27883afa95c","https://git.kernel.org/stable/c/e2d19969c8d9198ecc3090bcd5312ecd503a3339","https://git.kernel.org/stable/c/c85cff648a2bc92322912db5f1727ad05afae7b6","https://git.kernel.org/stable/c/9d20d48be2c4a071fb015eb09bda2cecd25daf34","https://git.kernel.org/stable/c/81c7a3c22a0f2808cf4ae0b4908f59763b23606d","https://git.kernel.org/stable/c/192cb0f1ca706d9a1bc36ae0ad5f666d1e4fd894","https://git.kernel.org/stable/c/7338031946bd06f6dff149e67b60c4cd083bfea8","https://git.kernel.org/stable/c/c1bb9336ae6b54a5f6a353c4bd4ed9a4307e429b"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-46275","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-46275","identifiers":["CVE-2026-46275"]},"retained":false,"historicalAffected":[]}],"coverage":[]}