syzbot


INFO: task hung in comedi_open

Status: upstream: reported C repro on 2025/12/25 02:22
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+793d40929aaafbecd56c@syzkaller.appspotmail.com
First crash: 18d, last: 1d18h
Bug presence (2)
Date Name Commit Repro Result
2025/12/29 linux-6.1.y (ToT) 50cbba13faa2 C [report] INFO: task hung in comedi_open
2025/12/29 upstream (ToT) 7839932417dd C Didn't crash
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: task hung in comedi_open origin:lts-only 1 C 6 1d18h 17d 0/2 upstream: reported C repro on 2025/12/26 05:04
linux-5.15 INFO: task hung in comedi_open origin:lts-only 1 C inconclusive 4 1d18h 27d 0/3 upstream: reported C repro on 2025/12/15 06:44
upstream INFO: task hung in comedi_open comedi 1 C 24 21d 160d 29/29 fixed on 2026/01/07 12:29

Sample crash report:
INFO: task syz.2.19:4523 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.19        state:D stack:26688 pid:4523  ppid:4401   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
 comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
 chrdev_open+0x597/0x670 fs/char_dev.c:414
 do_dentry_open+0x7e9/0x10d0 fs/open.c:882
 do_open fs/namei.c:3634 [inline]
 path_openat+0x25c6/0x2e70 fs/namei.c:3791
 do_filp_open+0x1c1/0x3c0 fs/namei.c:3818
 do_sys_openat2+0x142/0x490 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_openat fs/open.c:1352 [inline]
 __se_sys_openat fs/open.c:1347 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1347
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa1e0b8f749
RSP: 002b:00007ffcd8cdd9e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fa1e0de5fa0 RCX: 00007fa1e0b8f749
RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007fa1e0c13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa1e0de5fa0 R14: 00007fa1e0de5fa0 R15: 0000000000000004
 </TASK>
INFO: task syz.1.18:4524 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.18        state:D stack:26688 pid:4524  ppid:4393   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
 comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
 chrdev_open+0x597/0x670 fs/char_dev.c:414
 do_dentry_open+0x7e9/0x10d0 fs/open.c:882
 do_open fs/namei.c:3634 [inline]
 path_openat+0x25c6/0x2e70 fs/namei.c:3791
 do_filp_open+0x1c1/0x3c0 fs/namei.c:3818
 do_sys_openat2+0x142/0x490 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_openat fs/open.c:1352 [inline]
 __se_sys_openat fs/open.c:1347 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1347
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9ee278f749
RSP: 002b:00007ffde7ecd698 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f9ee29e5fa0 RCX: 00007f9ee278f749
RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007f9ee2813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9ee29e5fa0 R14: 00007f9ee29e5fa0 R15: 0000000000000004
 </TASK>
INFO: task syz.3.20:4525 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.20        state:D stack:26688 pid:4525  ppid:4396   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
 comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
 chrdev_open+0x597/0x670 fs/char_dev.c:414
 do_dentry_open+0x7e9/0x10d0 fs/open.c:882
 do_open fs/namei.c:3634 [inline]
 path_openat+0x25c6/0x2e70 fs/namei.c:3791
 do_filp_open+0x1c1/0x3c0 fs/namei.c:3818
 do_sys_openat2+0x142/0x490 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_openat fs/open.c:1352 [inline]
 __se_sys_openat fs/open.c:1347 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1347
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7acfb8f749
RSP: 002b:00007ffe9179be78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f7acfde5fa0 RCX: 00007f7acfb8f749
RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007f7acfc13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7acfde5fa0 R14: 00007f7acfde5fa0 R15: 0000000000000004
 </TASK>
INFO: task syz.0.17:4526 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:26688 pid:4526  ppid:4388   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
 comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
 chrdev_open+0x597/0x670 fs/char_dev.c:414
 do_dentry_open+0x7e9/0x10d0 fs/open.c:882
 do_open fs/namei.c:3634 [inline]
 path_openat+0x25c6/0x2e70 fs/namei.c:3791
 do_filp_open+0x1c1/0x3c0 fs/namei.c:3818
 do_sys_openat2+0x142/0x490 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_openat fs/open.c:1352 [inline]
 __se_sys_openat fs/open.c:1347 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1347
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0a94f8f749
RSP: 002b:00007ffdee4fbf28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f0a951e5fa0 RCX: 00007f0a94f8f749
RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007f0a95013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0a951e5fa0 R14: 00007f0a951e5fa0 R15: 0000000000000004
 </TASK>
INFO: task syz.5.22:4559 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.22        state:D stack:26688 pid:4559  ppid:4528   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
 comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
 chrdev_open+0x597/0x670 fs/char_dev.c:414
 do_dentry_open+0x7e9/0x10d0 fs/open.c:882
 do_open fs/namei.c:3634 [inline]
 path_openat+0x25c6/0x2e70 fs/namei.c:3791
 do_filp_open+0x1c1/0x3c0 fs/namei.c:3818
 do_sys_openat2+0x142/0x490 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_openat fs/open.c:1352 [inline]
 __se_sys_openat fs/open.c:1347 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1347
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5456f8f749
RSP: 002b:00007fff5ab71038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f54571e5fa0 RCX: 00007f5456f8f749
RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007f5457013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f54571e5fa0 R14: 00007f54571e5fa0 R15: 0000000000000004
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/u4:4/75:
 #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffff8880b8e27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x398/0x6d0 kernel/sched/psi.c:999
2 locks held by getty/4029:
 #0: ffff88814d289098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
2 locks held by kworker/1:7/4351:
 #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90002fa7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
2 locks held by syz.4.21/4455:
1 lock held by syz.2.19/4523:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.1.18/4524:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.3.20/4525:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.0.17/4526:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.5.22/4559:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.6.23/4638:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.7.24/4681:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.9.26/4682:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.8.25/4683:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.4.27/4695:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.2.28/4717:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.1.29/4789:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.3.31/4805:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.0.30/4811:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.5.32/4819:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.6.33/4836:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.7.34/4873:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.8.35/4945:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.9.36/4966:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.4.37/4968:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.2.38/4969:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.1.39/4986:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.3.40/5007:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.0.41/5058:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz-executor/5077:
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz.5.42/5115:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
8 locks held by syz-executor/5117:
 #0: ffff88807dc2c460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580
 #1: ffff88804b16c888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
 #2: ffff888144790a00 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff888144790a00 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
 #3: ffffffff8d44d168 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x360 drivers/net/netdevsim/bus.c:209
 #4: ffff888142b010e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline]
 #4: ffff888142b010e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1080 [inline]
 #4: ffff888142b010e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb2/0x850 drivers/base/dd.c:1283
 #5: ffff8880762782f8 (&devlink->lock_key#21){+.+.}-{3:3}, at: nsim_drv_remove+0x54/0x160 drivers/net/netdevsim/dev.c:1677
 #6: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3b/0x150 drivers/net/netdevsim/netdev.c:381
 #7: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #7: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962
1 lock held by syz.6.43/5121:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811
1 lock held by syz.7.44/5130:
 #0: ffff88802eb6b8f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xbc/0x580 drivers/comedi/comedi_fops.c:2811

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xeee/0xf30 kernel/hung_task.c:377
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4637 Comm: kworker/u4:8 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: phy42 ieee80211_iface_work
RIP: 0010:stack_trace_consume_entry+0x0/0x270 kernel/stacktrace.c:83
Code: 48 8b 0c 25 28 00 00 00 48 3b 4c 24 78 75 09 48 8d 65 f0 5b 41 5e 5d c3 e8 1d a5 a0 08 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <55> 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 ba 00 00 00 00 00 fc
RSP: 0018:ffffc900038270a0 EFLAGS: 00000286
RAX: ffffffff81d0e81b RBX: ffffc90003827160 RCX: 0000000080000000
RDX: ffffc90003827001 RSI: ffffffff81d0e81b RDI: ffffc90003827160
RBP: ffffc90003827130 R08: ffffc900038271d0 R09: ffffc900038270f8
R10: fffff52000704e21 R11: 1ffff92000704e1f R12: ffff888018fcd940
R13: 0000000000000000 R14: ffffffff816fc770 R15: ffffc900038270a8
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1f2417ae9c CR3: 000000000c68e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_stack_walk+0x100/0x140 arch/x86/kernel/stacktrace.c:27
 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slab_common.c:936 [inline]
 __kmalloc+0xb0/0x240 mm/slab_common.c:949
 kmalloc include/linux/slab.h:568 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 cfg80211_inform_single_bss_frame_data net/wireless/scan.c:2484 [inline]
 cfg80211_inform_bss_frame_data+0x6a0/0x1370 net/wireless/scan.c:2545
 ieee80211_bss_info_update+0x734/0xbc0 net/mac80211/scan.c:190
 ieee80211_rx_bss_info net/mac80211/ibss.c:1120 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1609 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x17b4/0x2b10 net/mac80211/ibss.c:1638
 ieee80211_iface_process_skb net/mac80211/iface.c:1679 [inline]
 ieee80211_iface_work+0x726/0xc80 net/mac80211/iface.c:1733
 process_one_work+0x898/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/26 10:29 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in comedi_open
2025/12/25 18:51 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in comedi_open
2025/12/25 16:35 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in comedi_open
2025/12/25 14:11 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in comedi_open
2025/12/25 11:43 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in comedi_open
2025/12/25 09:07 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in comedi_open
2025/12/25 06:52 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in comedi_open
2025/12/25 04:29 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in comedi_open
2025/12/25 02:21 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in comedi_open
2026/01/10 11:39 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in comedi_open
* Struck through repros no longer work on HEAD.