{ "affected": [ { "ranges": [ { "events": [ { "introduced": "3b799254cf6f481460719023d7a18f46651e5e7f" }, { "fixed": "78aad93e938f013d9272fe0ee168f27883afa95c" }, { "fixed": "e2d19969c8d9198ecc3090bcd5312ecd503a3339" }, { "fixed": "c85cff648a2bc92322912db5f1727ad05afae7b6" }, { "fixed": "9d20d48be2c4a071fb015eb09bda2cecd25daf34" }, { "fixed": "81c7a3c22a0f2808cf4ae0b4908f59763b23606d" }, { "fixed": "192cb0f1ca706d9a1bc36ae0ad5f666d1e4fd894" }, { "fixed": "7338031946bd06f6dff149e67b60c4cd083bfea8" }, { "fixed": "c1bb9336ae6b54a5f6a353c4bd4ed9a4307e429b" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "0" }, { "last_affected": "cd27019bc149f20f12ebec943c2b4c775745a5a0" }, { "last_affected": "aea63181b6fcb6b9ccde1ada9ea51be19c4015af" }, { "last_affected": "0d234d1135dcd8876de0576dac68efd0a87eef87" }, { "last_affected": "3fe978892ab46efc2f3830d9abc015eff72caaf9" }, { "last_affected": "0d987e14bebaf0f67ee7dbefaf6165c62cd1d27f" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "4.14.203" }, { "fixed": "4.15" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "4.19.153" }, { "fixed": "4.20" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "5.4.73" }, { "fixed": "5.5" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "5.8.17" }, { "fixed": "5.9" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "5.9.2" }, { "fixed": "5.10" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" } ] }, { "package": { "ecosystem": "Linux", "name": "Kernel" }, "ranges": [ { "events": [ { "introduced": "5.10.0" }, { "fixed": "5.10.258" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "5.11.0" }, { "fixed": "5.15.209" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "5.16.0" }, { "fixed": "6.1.175" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.2.0" }, { "fixed": "6.6.142" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.7.0" }, { "fixed": "6.12.92" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.13.0" }, { "fixed": "6.18.34" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.19.0" }, { "fixed": "7.0.11" } ], "type": "ECOSYSTEM" } ] } ], "database_specific": { "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46275.json" }, "details": "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-\u003etx_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-\u003eproto-\u003eclose(hu) causes a UAF\n when vendor specific protocol close callbacks dereference hu-\u003ehdev.\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-\u003ehdev\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(\u0026hu-\u003ewrite_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-\u003eproto-\u003eflush(). This is perfectly safe in the tty_close path\n because hu-\u003eproto-\u003eclose() executes shortly after, which intrinsically\n purges all protocol SKB queues and tears down the state.\n3. Relocating hu-\u003eproto-\u003eclose(hu) strictly prior to hci_free_dev(hdev)\n across all close and error paths to prevent vendor-level UAFs.\n4. Moving the hdev-\u003estat.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(\u0026hu-\u003ewrite_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.", "id": "CVE-2026-46275", "modified": "2026-07-15T01:49:17.975679447Z", "published": "2026-06-08T14:30:54.232Z", "references": [ { "type": "WEB", "url": "https://git.kernel.org/stable/c/192cb0f1ca706d9a1bc36ae0ad5f666d1e4fd894" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/7338031946bd06f6dff149e67b60c4cd083bfea8" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/78aad93e938f013d9272fe0ee168f27883afa95c" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/81c7a3c22a0f2808cf4ae0b4908f59763b23606d" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/9d20d48be2c4a071fb015eb09bda2cecd25daf34" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/c1bb9336ae6b54a5f6a353c4bd4ed9a4307e429b" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/c85cff648a2bc92322912db5f1727ad05afae7b6" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/e2d19969c8d9198ecc3090bcd5312ecd503a3339" }, { "type": "ADVISORY", "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46275.json" }, { "type": "ADVISORY", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46275" }, { "type": "PACKAGE", "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git" } ], "schema_version": "1.8.0", "severity": [ { "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "type": "CVSS_V3" } ], "summary": "Bluetooth: hci_uart: fix UAFs and race conditions in close and init paths" }