INFO: task hung in tracing_open_file_tr

Status: upstream: reported syz repro on 2026/08/14 20:56
Reported-by: syzbot+f16c07a111bd5b958c12@syzkaller.appspotmail.com
First crash: 4d08h, last: 2d06h

Sample crash report:
INFO: task syz.2.19:4496 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:26736 pid:4496  ppid:4406   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0x107f/0x4030 kernel/sched/core.c:6563
 schedule+0xb9/0x180 kernel/sched/core.c:6639
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747
 trace_array_get kernel/trace/trace.c:461 [inline]
 tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
 do_dentry_open+0x7dd/0x10b0 fs/open.c:882
 do_open fs/namei.c:3634 [inline]
 path_openat+0x2674/0x2f10 fs/namei.c:3791
 do_filp_open+0x1ee/0x420 fs/namei.c:3818
 do_sys_openat2+0x14b/0x4f0 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:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f171599e0d9
RSP: 002b:00007ffdb1a95cb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f1715c25fa0 RCX: 00007f171599e0d9
RDX: 0000000000000101 RSI: 0000200000000400 RDI: ffffffffffffff9c
RBP: 00007f1715a35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1715c25fac R14: 00007f1715c25fa0 R15: 00007f1715c25fa0
 </TASK>
INFO: task syz.4.21:4499 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.21        state:D stack:26688 pid:4499  ppid:4414   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0x107f/0x4030 kernel/sched/core.c:6563
 schedule+0xb9/0x180 kernel/sched/core.c:6639
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747
 trace_array_get kernel/trace/trace.c:461 [inline]
 tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
 do_dentry_open+0x7dd/0x10b0 fs/open.c:882
 do_open fs/namei.c:3634 [inline]
 path_openat+0x2674/0x2f10 fs/namei.c:3791
 do_filp_open+0x1ee/0x420 fs/namei.c:3818
 do_sys_openat2+0x14b/0x4f0 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:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f02d9b9e0d9
RSP: 002b:00007ffeeed41538 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f02d9e25fa0 RCX: 00007f02d9b9e0d9
RDX: 0000000000000101 RSI: 0000200000000400 RDI: ffffffffffffff9c
RBP: 00007f02d9c35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f02d9e25fac R14: 00007f02d9e25fa0 R15: 00007f02d9e25fa0
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/7:
 #0: ffff88814d46c538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #1: ffffc900000c7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1500 net/ipv6/addrconf.c:4138
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8cb2e4f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8cb2ed10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6527
2 locks held by getty/4028:
 #0: ffff88802f7bb098 (&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+0x41e/0x1360 drivers/tty/n_tty.c:2198
2 locks held by kworker/0:8/4374:
 #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #1: ffffc90004597d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
3 locks held by kworker/1:4/4391:
 #0: ffff88814d46c538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #1: ffffc90003207d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1500 net/ipv6/addrconf.c:4138
5 locks held by syz.0.17/4481:
1 lock held by syz.2.19/4496:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.4.21/4499:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.1.18/4510:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.3.20/4512:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.5.22/4534:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.6.23/4586:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.7.24/4588:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.8.25/4611:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.9.26/4612:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.2.33/4690:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
3 locks held by kworker/u4:8/4697:
 #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #1: ffffc90003cd7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263
1 lock held by syz.4.36/4718:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.3.44/4726:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.1.43/4727:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.5.74/4788:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.6.84/4816:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.7.91/4856:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.8.92/4859:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz.9.110/4888:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
1 lock held by syz-executor/4901:
 #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x80d/0xfb0 net/core/rtnetlink.c:6163
1 lock held by syz-executor/4904:
 #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x80d/0xfb0 net/core/rtnetlink.c:6163
1 lock held by syz.2.122/4913:
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: trace_array_get kernel/trace/trace.c:461 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_check_open_get_tr kernel/trace/trace.c:511 [inline]
 #0: ffffffff8cb77748 (trace_types_lock){+.+.}-{3:3}, at: tracing_open_file_tr+0xab/0x2f0 kernel/trace/trace.c:4892
8 locks held by syz-executor/4933:
 #0: ffff88807e260460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
 #1: ffff88804c6a5088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1d8/0x520 fs/kernfs/file.c:343
 #2: ffff888144b45a00 (kn->active#59){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff888144b45a00 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x520 fs/kernfs/file.c:344
 #3: ffffffff8d66a3a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd3/0x370 drivers/net/netdevsim/bus.c:209
 #4: ffff8880569ec0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
 #4: ffff8880569ec0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
 #4: ffff8880569ec0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
 #5: ffff8880569eb2f8 (&devlink->lock_key#16){+.+.}-{3:3}, at: nsim_drv_remove+0x54/0x170 drivers/net/netdevsim/dev.c:1678
 #6: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3b/0x150 drivers/net/netdevsim/netdev.c:381
 #7: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #7: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
1 lock held by syz-executor/4960:
 #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x80d/0xfb0 net/core/rtnetlink.c:6163
6 locks held by syz.0.155/4962:
 #0: ffff88807db4e460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
 #1: ffff888076056888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1d8/0x520 fs/kernfs/file.c:343
 #2: ffffffff8cb56648 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:442 [inline]
 #2: ffffffff8cb56648 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xe5/0x220 kernel/cgroup/cgroup.c:1700
 #3: ffffffff8c9ca530 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2476 [inline]
 #3: ffffffff8c9ca530 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x186/0x610 kernel/cgroup/cgroup.c:2983
 #4: ffffffff8cb56830 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2478 [inline]
 #4: ffffffff8cb56830 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x19c/0x610 kernel/cgroup/cgroup.c:2983
 #5: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #5: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3e6/0x460 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+0xf0e/0xf50 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 11 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:unwind_next_frame+0x6bf/0x1fd0 arch/x86/kernel/unwind_orc.c:471
Code: a7 59 9a 00 49 8b 16 4d 8d 74 24 01 4c 89 e0 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 90 14 00 00 4c 89 f0 48 c1 e8 03 0f b6 04 28 <84> c0 0f 85 a5 14 00 00 49 0f bf 04 24 48 01 c2 48 89 14 24 4d 8d
RSP: 0018:ffffc90000107680 EFLAGS: 00000a07
RAX: 0000000000000000 RBX: ffffc90000107728 RCX: ffffffff8e37ed5c
RDX: ffffc90000107ae0 RSI: ffffffff8e37ed54 RDI: 0000000000000001
RBP: dffffc0000000000 R08: 000000000000000d R09: 0000000000000003
R10: dffffc0000000000 R11: fffff52000020ef1 R12: ffffffff8eab5284
R13: ffffffff8eab5288 R14: ffffffff8eab5285 R15: 1ffffffff1d56a51
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe199670000 CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1729 [inline]
 slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755
 slab_free mm/slub.c:3687 [inline]
 kmem_cache_free+0xf7/0x2a0 mm/slub.c:3709
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
 nsim_dev_trap_report_work+0x71f/0xa80 drivers/net/netdevsim/dev.c:851
 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaf5/0x12a0 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 (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/16 23:39 linux-6.1.y e4f7d8be268e 746171ee .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in tracing_open_file_tr
2026/08/16 23:02 linux-6.1.y e4f7d8be268e 746171ee .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in tracing_open_file_tr
2026/08/16 18:47 linux-6.1.y e4f7d8be268e 746171ee .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in tracing_open_file_tr
2026/08/16 15:17 linux-6.1.y e4f7d8be268e 746171ee .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in tracing_open_file_tr
2026/08/16 09:33 linux-6.1.y e4f7d8be268e 746171ee .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in tracing_open_file_tr
2026/08/16 05:18 linux-6.1.y e4f7d8be268e 746171ee .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in tracing_open_file_tr
2026/08/16 01:10 linux-6.1.y e4f7d8be268e 746171ee .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in tracing_open_file_tr
2026/08/14 20:56 linux-6.1.y e4f7d8be268e 6f9b3e89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in tracing_open_file_tr
* Struck through repros no longer work on HEAD.