{"id":"CVE-2022-50166","title":"Bluetooth: When HCI work queue is drained, only queue chained work","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: When HCI work queue is drained, only queue chained work\n\nThe HCI command, event, and data packet processing workqueue is drained\nto avoid deadlock in commit\n…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 76727c02c1e14a2b561b806fa1d08acc1619ad27 < 4bf367fa1fefabdf14938d0ac9ed60020389112e","Linux >= 76727c02c1e14a2b561b806fa1d08acc1619ad27 < 3b382555706558f5c0587862b6dc03e96a252bba","Linux >= 76727c02c1e14a2b561b806fa1d08acc1619ad27 < 877afadad2dce8aae1f2aad8ce47e072d4f6165e","Linux 3.19"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T19:55:25.368566Z"},"published":"2025-06-18","updated":"2026-11-05","sourceUpdated":"2026-11-05T20:00:19.165Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2022-50166","references":[{"url":"https://git.kernel.org/stable/c/4bf367fa1fefabdf14938d0ac9ed60020389112e"},{"url":"https://git.kernel.org/stable/c/3b382555706558f5c0587862b6dc03e96a252bba"},{"url":"https://git.kernel.org/stable/c/877afadad2dce8aae1f2aad8ce47e072d4f6165e"}],"tags":["cve.org"],"epss":0.00184,"epssPercentile":0.08031,"ingestedAt":"2026-11-05T22:38:31.688Z","slug":"CVE-2022-50166","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: When HCI work queue is drained, only queue chained work\n\nThe HCI command, event, and data packet processing workqueue is drained\nto avoid deadlock in commit\n76727c02c1e1 (\"Bluetooth: Call drain_workqueue() before resetting state\").\n\nThere is another delayed work, which will queue command to this drained\nworkqueue. Which results in the following error report:\n\nBluetooth: hci2: command 0x040f tx timeout\nWARNING: CPU: 1 PID: 18374 at kernel/workqueue.c:1438 __queue_work+0xdad/0x1140\nWorkqueue: events hci_cmd_timeout\nRIP: 0010:__queue_work+0xdad/0x1140\nRSP: 0000:ffffc90002cffc60 EFLAGS: 00010093\nRAX: 0000000000000000 RBX: ffff8880b9d3ec00 RCX: 0000000000000000\nRDX: ffff888024ba0000 RSI: ffffffff814e048d RDI: ffff8880b9d3ec08\nRBP: 0000000000000008 R08: 0000000000000000 R09: 00000000b9d39700\nR10: ffffffff814f73c6 R11: 0000000000000000 R12: ffff88807cce4c60\nR13: 0000000000000000 R14: ffff8880796d8800 R15: ffff8880796d8800\nFS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 000000c0174b4000 CR3: 000000007cae9000 CR4: 00000000003506e0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n <TASK>\n ? queue_work_on+0xcb/0x110\n ? lockdep_hardirqs_off+0x90/0xd0\n queue_work_on+0xee/0x110\n process_one_work+0x996/0x1610\n ? pwq_dec_nr_in_flight+0x2a0/0x2a0\n ? rwlock_bug.part.0+0x90/0x90\n ? _raw_spin_lock_irq+0x41/0x50\n worker_thread+0x665/0x1080\n ? process_one_work+0x1610/0x1610\n kthread+0x2e9/0x3a0\n ? kthread_complete_and_exit+0x40/0x40\n ret_from_fork+0x1f/0x30\n </TASK>\n\nTo fix this, we can add a new HCI_DRAIN_WQ flag, and don't queue the\ntimeout workqueue while command workqueue is draining.\n\n## Affected\n\n- `Linux >= 76727c02c1e14a2b561b806fa1d08acc1619ad27 < 4bf367fa1fefabdf14938d0ac9ed60020389112e`\n- `Linux >= 76727c02c1e14a2b561b806fa1d08acc1619ad27 < 3b382555706558f5c0587862b6dc03e96a252bba`\n- `Linux >= 76727c02c1e14a2b561b806fa1d08acc1619ad27 < 877afadad2dce8aae1f2aad8ce47e072d4f6165e`\n- `Linux 3.19`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}