{"id":"CVE-2026-23167","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-23167","generatedAt":"2026-10-28T03:41:15.722Z","title":"In the Linux kernel, the following vulnerability has been resolved: nfc: nci: Fix race between rfkill and nci_unregister_device(). syzbot reported the splat below [0] without a repro.","description":"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->conn_info_list\n\n  2) nci_rx_work() could try to queue nci_conn_info to\n     ndev->conn_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 <67> 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 <TASK>\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 <48> 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---","published":"2026-02-14T16:15:57.000Z","lastModified":"2026-06-17T10:21:01.000Z","status":"Analyzed","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":4.7,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-362"],"affected":["linux/linux kernel"],"epss":{"score":0.00099,"percentile":0.00799,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.10%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/126cd30cad37bc7c2c85fe2df2a522d4edf0a5c5","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/546eba0b10989de9ccc7fd619e874a30561e2b88","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8ea4d96419fb20f15a52ce657d49f1e7c91eb7ac","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c3369fc5e6120a72169e71acd72e987907a682af","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cd4412d5905ee580e96c48360dc98fcd9e6f3208","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d2492688bb9fed6ab6e313682c387ae71a66ebae","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/eaa5da5130deda26420273d4610cf6e4f794ed75","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-23167","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}