{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46275","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-05-13T15:03:33.109Z","datePublished":"2026-06-08T14:30:54.232Z","dateUpdated":"2026-06-14T18:05:39.086Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-06-14T18:05:39.086Z"},"descriptions":[{"lang":"en","value":"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."}],"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"}}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/bluetooth/hci_ldisc.c"],"versions":[{"version":"3b799254cf6f481460719023d7a18f46651e5e7f","lessThan":"78aad93e938f013d9272fe0ee168f27883afa95c","status":"affected","versionType":"git"},{"version":"3b799254cf6f481460719023d7a18f46651e5e7f","lessThan":"e2d19969c8d9198ecc3090bcd5312ecd503a3339","status":"affected","versionType":"git"},{"version":"3b799254cf6f481460719023d7a18f46651e5e7f","lessThan":"c85cff648a2bc92322912db5f1727ad05afae7b6","status":"affected","versionType":"git"},{"version":"3b799254cf6f481460719023d7a18f46651e5e7f","lessThan":"9d20d48be2c4a071fb015eb09bda2cecd25daf34","status":"affected","versionType":"git"},{"version":"3b799254cf6f481460719023d7a18f46651e5e7f","lessThan":"81c7a3c22a0f2808cf4ae0b4908f59763b23606d","status":"affected","versionType":"git"},{"version":"3b799254cf6f481460719023d7a18f46651e5e7f","lessThan":"192cb0f1ca706d9a1bc36ae0ad5f666d1e4fd894","status":"affected","versionType":"git"},{"version":"3b799254cf6f481460719023d7a18f46651e5e7f","lessThan":"7338031946bd06f6dff149e67b60c4cd083bfea8","status":"affected","versionType":"git"},{"version":"3b799254cf6f481460719023d7a18f46651e5e7f","lessThan":"c1bb9336ae6b54a5f6a353c4bd4ed9a4307e429b","status":"affected","versionType":"git"},{"version":"cd27019bc149f20f12ebec943c2b4c775745a5a0","status":"affected","versionType":"git"},{"version":"aea63181b6fcb6b9ccde1ada9ea51be19c4015af","status":"affected","versionType":"git"},{"version":"0d234d1135dcd8876de0576dac68efd0a87eef87","status":"affected","versionType":"git"},{"version":"3fe978892ab46efc2f3830d9abc015eff72caaf9","status":"affected","versionType":"git"},{"version":"0d987e14bebaf0f67ee7dbefaf6165c62cd1d27f","status":"affected","versionType":"git"},{"version":"4.14.203","lessThan":"4.15","status":"affected","versionType":"semver"},{"version":"4.19.153","lessThan":"4.20","status":"affected","versionType":"semver"},{"version":"5.4.73","lessThan":"5.5","status":"affected","versionType":"semver"},{"version":"5.8.17","lessThan":"5.9","status":"affected","versionType":"semver"},{"version":"5.9.2","lessThan":"5.10","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/bluetooth/hci_ldisc.c"],"versions":[{"version":"5.10","status":"affected"},{"version":"0","lessThan":"5.10","status":"unaffected","versionType":"semver"},{"version":"5.10.258","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.209","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.175","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.142","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.92","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.34","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.11","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.6.142"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.12.92"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.18.34"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"7.0.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"7.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14.203"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19.153"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4.73"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8.17"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/78aad93e938f013d9272fe0ee168f27883afa95c"},{"url":"https://git.kernel.org/stable/c/e2d19969c8d9198ecc3090bcd5312ecd503a3339"},{"url":"https://git.kernel.org/stable/c/c85cff648a2bc92322912db5f1727ad05afae7b6"},{"url":"https://git.kernel.org/stable/c/9d20d48be2c4a071fb015eb09bda2cecd25daf34"},{"url":"https://git.kernel.org/stable/c/81c7a3c22a0f2808cf4ae0b4908f59763b23606d"},{"url":"https://git.kernel.org/stable/c/192cb0f1ca706d9a1bc36ae0ad5f666d1e4fd894"},{"url":"https://git.kernel.org/stable/c/7338031946bd06f6dff149e67b60c4cd083bfea8"},{"url":"https://git.kernel.org/stable/c/c1bb9336ae6b54a5f6a353c4bd4ed9a4307e429b"}],"title":"Bluetooth: hci_uart: fix UAFs and race conditions in close and init paths","x_generator":{"engine":"bippy-1.2.0"}}}}