syzbot


INFO: task hung in nfc_rfkill_set_block

Status: upstream: reported on 2025/08/21 17:40
Reported-by: syzbot+859496b7f2c55cbea307@syzkaller.appspotmail.com
First crash: 6d13h, last: 6d13h
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in nfc_rfkill_set_block nfc net 1 C done done 586 11h52m 1016d 0/29 upstream: reported C repro on 2022/11/15 16:56
linux-5.15 INFO: task hung in nfc_rfkill_set_block origin:upstream 1 C error 16 58d 890d 0/3 upstream: reported C repro on 2023/03/21 08:35
linux-6.1 INFO: task hung in nfc_rfkill_set_block origin:upstream 1 C error 24 10d 840d 0/3 upstream: reported C repro on 2023/05/10 12:44

Sample crash report:
INFO: task kworker/1:0:23 blocked for more than 143 seconds.
      Not tainted 6.6.102-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0     state:D stack:21736 pid:23    ppid:2      flags:0x00004000
Workqueue: events rfkill_op_handler
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
 device_lock include/linux/device.h:992 [inline]
 nfc_dev_down net/nfc/core.c:143 [inline]
 nfc_rfkill_set_block+0x50/0x2e0 net/nfc/core.c:179
 rfkill_set_block+0x1c6/0x420 net/rfkill/core.c:346
 rfkill_epo+0x79/0x180 net/rfkill/core.c:466
 __rfkill_handle_global_op net/rfkill/input.c:60 [inline]
 rfkill_op_handler+0x84/0x240 net/rfkill/input.c:108
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
INFO: task kworker/1:3:5780 blocked for more than 143 seconds.
      Not tainted 6.6.102-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:3     state:D stack:20792 pid:5780  ppid:2      flags:0x00004000
Workqueue: events rfkill_global_led_trigger_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
 rfkill_global_led_trigger_worker+0x27/0xd0 net/rfkill/core.c:182
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
INFO: task syz.9.2118:13125 blocked for more than 143 seconds.
      Not tainted 6.6.102-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.2118      state:D stack:27016 pid:13125 ppid:8327   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
 rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1149
 nfc_unregister_device+0x96/0x2a0 net/nfc/core.c:1167
 virtual_ncidev_close+0x59/0x90 drivers/nfc/virtual_ncidev.c:172
 __fput+0x234/0x970 fs/file_table.c:384
 task_work_run+0x1ce/0x250 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f10c9b8ebe9
RSP: 002b:00007ffe0ac26118 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000064438 RCX: 00007f10c9b8ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f10c9db7da0 R08: 0000000000000001 R09: 000000060ac2640f
R10: 0000001b2c420000 R11: 0000000000000246 R12: 00007f10c9db5fac
R13: 00007f10c9db5fa0 R14: ffffffffffffffff R15: 00007ffe0ac26230
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/1:0/23:
 #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc900001d7d00 ((rfkill_op_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc900001d7d00 ((rfkill_op_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffffffff8e297268 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_epo+0x47/0x180 net/rfkill/core.c:462
 #3: ffff888023401100 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline]
 #3: ffff888023401100 (&dev->mutex){....}-{3:3}, at: nfc_dev_down net/nfc/core.c:143 [inline]
 #3: ffff888023401100 (&dev->mutex){....}-{3:3}, at: nfc_rfkill_set_block+0x50/0x2e0 net/nfc/core.c:179
1 lock held by khungtaskd/29:
 #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
4 locks held by kworker/u4:2/42:
5 locks held by kworker/u4:5/142:
2 locks held by getty/5543:
 #0: ffff88802d22b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
3 locks held by kworker/1:3/5780:
 #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc9000461fd00 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc9000461fd00 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffffffff8e297268 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_global_led_trigger_worker+0x27/0xd0 net/rfkill/core.c:182
1 lock held by syz.0.349/7081:
 #0: ffffffff8e297268 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1149
1 lock held by syz-executor/8322:
 #0: ffffffff8e297268 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1149
1 lock held by syz-executor/12541:
 #0: ffffffff8e297268 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1149
2 locks held by syz.9.2118/13125:
 #0: ffff888023401100 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline]
 #0: ffff888023401100 (&dev->mutex){....}-{3:3}, at: nfc_unregister_device+0x63/0x2a0 net/nfc/core.c:1165
 #1: ffffffff8e297268 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1149
2 locks held by syz-executor/13246:
 #0: ffff88805dc42918 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x6e0 drivers/bluetooth/hci_vhci.c:471
 #1: ffffffff8e297268 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x37/0x8e0 net/rfkill/core.c:1075
2 locks held by syz-executor/13265:
 #0: ffff88807d4ca118 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x6e0 drivers/bluetooth/hci_vhci.c:471
 #1: ffffffff8e297268 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x37/0x8e0 net/rfkill/core.c:1075
2 locks held by syz-executor/13267:
 #0: ffff88807698e118 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x6e0 drivers/bluetooth/hci_vhci.c:471
 #1: ffffffff8e297268 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x37/0x8e0 net/rfkill/core.c:1075

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf41/0xf80 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 142 Comm: kworker/u4:5 Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: krdsd rds_connect_worker
RIP: 0010:unwind_get_return_address+0x9/0xc0 arch/x86/kernel/unwind_orc.c:365
Code: 80 c1 03 38 c1 0f 8c 49 ff ff ff 48 89 df e8 1e 31 a2 00 e9 3c ff ff ff e8 14 a6 32 09 0f 1f 40 00 f3 0f 1e fa 55 41 57 41 56 <53> 48 89 fb 49 be 00 00 00 00 00 fc ff df e8 e4 e9 4a 00 48 89 d8
RSP: 0018:ffffc90002db7388 EFLAGS: 00000293
RAX: ffffffff81321072 RBX: ffffc90002db7460 RCX: ffff88801afc3c00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: ffffc90002db73a8
RBP: ffffc90002db7430 R08: ffff88801afc3c00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff81e5f9d7
R13: 1ffff920005b6ea0 R14: ffffffff817466a0 R15: ffffc90002db73a8
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005612614d8000 CR3: 000000000cb30000 CR4: 00000000003506e0
DR0: 00000000c5c0f6bd DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf7/0x1f0 mm/page_owner.c:128
 __reset_page_owner+0x4e/0x190 mm/page_owner.c:149
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1154 [inline]
 free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
 discard_slab mm/slub.c:2122 [inline]
 __unfreeze_partials+0x1cf/0x210 mm/slub.c:2662
 put_cpu_partial+0x17c/0x250 mm/slub.c:2738
 __slab_free+0x31d/0x410 mm/slub.c:3686
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3485 [inline]
 slab_alloc mm/slub.c:3493 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3500 [inline]
 kmem_cache_alloc_lru+0x115/0x2e0 mm/slub.c:3516
 alloc_inode_sb include/linux/fs.h:2946 [inline]
 sock_alloc_inode+0x28/0xc0 net/socket.c:308
 alloc_inode fs/inode.c:261 [inline]
 new_inode_pseudo+0x63/0x1d0 fs/inode.c:1049
 sock_alloc net/socket.c:634 [inline]
 __sock_create+0x12d/0x940 net/socket.c:1535
 rds_tcp_conn_path_connect+0x283/0x680 net/rds/tcp_connect.c:-1
 rds_connect_worker+0x1d2/0x280 net/rds/threads.c:176
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/21 17:39 linux-6.6.y bb9c90ab9c5a 3e79b825 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in nfc_rfkill_set_block
* Struck through repros no longer work on HEAD.