{"id":"AZL-77715","summary":"CVE-2026-23167 affecting package kernel for versions less than 6.6.126.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfc: nci: Fix race between rfkill and nci_unregister_device().\n\nsyzbot reported the splat below [0] without a repro.\n\nIt indicates that struct nci_dev.cmd_wq had been destroyed before\nnci_close_device() was called via rfkill.\n\nnci_dev.cmd_wq is only destroyed in nci_unregister_device(), which\n(I think) was called from virtual_ncidev_close() when syzbot close()d\nan fd of virtual_ncidev.\n\nThe problem is that nci_unregister_device() destroys nci_dev.cmd_wq\nfirst and then calls nfc_unregister_device(), which removes the\ndevice from rfkill by rfkill_unregister().\n\nSo, the device is still visible via rfkill even after nci_dev.cmd_wq\nis destroyed.\n\nLet's unregister the device from rfkill first in nci_unregister_device().\n\nNote that we cannot call nfc_unregister_device() before\nnci_close_device() because\n\n  1) nfc_unregister_device() calls device_del() which frees\n     all memory allocated by devm_kzalloc() and linked to\n     ndev-\u003econn_info_list\n\n  2) nci_rx_work() could try to queue nci_conn_info to\n     ndev-\u003econn_info_list which could be leaked\n\nThus, nfc_unregister_device() is split into two functions so we\ncan remove rfkill interfaces only before nci_close_device().\n\n[0]:\nDEBUG_LOCKS_WARN_ON(1)\nWARNING: kernel/locking/lockdep.c:238 at hlock_class kernel/locking/lockdep.c:238 [inline], CPU#0: syz.0.8675/6349\nWARNING: kernel/locking/lockdep.c:238 at check_wait_context kernel/locking/lockdep.c:4854 [inline], CPU#0: syz.0.8675/6349\nWARNING: kernel/locking/lockdep.c:238 at __lock_acquire+0x39d/0x2cf0 kernel/locking/lockdep.c:5187, CPU#0: syz.0.8675/6349\nModules linked in:\nCPU: 0 UID: 0 PID: 6349 Comm: syz.0.8675 Not tainted syzkaller #0 PREEMPT(full)\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026\nRIP: 0010:hlock_class kernel/locking/lockdep.c:238 [inline]\nRIP: 0010:check_wait_context kernel/locking/lockdep.c:4854 [inline]\nRIP: 0010:__lock_acquire+0x3a4/0x2cf0 kernel/locking/lockdep.c:5187\nCode: 18 00 4c 8b 74 24 08 75 27 90 e8 17 f2 fc 02 85 c0 74 1c 83 3d 50 e0 4e 0e 00 75 13 48 8d 3d 43 f7 51 0e 48 c7 c6 8b 3a de 8d \u003c67\u003e 48 0f b9 3a 90 31 c0 0f b6 98 c4 00 00 00 41 8b 45 20 25 ff 1f\nRSP: 0018:ffffc9000c767680 EFLAGS: 00010046\nRAX: 0000000000000001 RBX: 0000000000040000 RCX: 0000000000080000\nRDX: ffffc90013080000 RSI: ffffffff8dde3a8b RDI: ffffffff8ff24ca0\nRBP: 0000000000000003 R08: ffffffff8fef35a3 R09: 1ffffffff1fde6b4\nR10: dffffc0000000000 R11: fffffbfff1fde6b5 R12: 00000000000012a2\nR13: ffff888030338ba8 R14: ffff888030338000 R15: ffff888030338b30\nFS:  00007fa5995f66c0(0000) GS:ffff8881256f8000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f7e72f842d0 CR3: 00000000485a0000 CR4: 00000000003526f0\nCall Trace:\n \u003cTASK\u003e\n lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868\n touch_wq_lockdep_map+0xcb/0x180 kernel/workqueue.c:3940\n __flush_workqueue+0x14b/0x14f0 kernel/workqueue.c:3982\n nci_close_device+0x302/0x630 net/nfc/nci/core.c:567\n nci_dev_down+0x3b/0x50 net/nfc/nci/core.c:639\n nfc_dev_down+0x152/0x290 net/nfc/core.c:161\n nfc_rfkill_set_block+0x2d/0x100 net/nfc/core.c:179\n rfkill_set_block+0x1d2/0x440 net/rfkill/core.c:346\n rfkill_fop_write+0x461/0x5a0 net/rfkill/core.c:1301\n vfs_write+0x29a/0xb90 fs/read_write.c:684\n ksys_write+0x150/0x270 fs/read_write.c:738\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7fa59b39acb9\nCode: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 \u003c48\u003e 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007fa5995f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001\nRAX: ffffffffffffffda RBX: 00007fa59b615fa0 RCX: 00007fa59b39acb9\nRDX: 0000000000000008 RSI: 0000200000000080 RDI: 0000000000000007\nRBP: 00007fa59b408bf7 R08: \n---truncated---","modified":"2026-08-28T17:45:40.299220932Z","published":"2026-02-14T16:15:56Z","upstream":["CVE-2026-23167"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23167"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.126.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-77715.json"}}],"schema_version":"1.9.0"}