syzbot


INFO: task hung in unwind_next_frame (2)

Status: auto-obsoleted due to no activity on 2026/06/26 23:30
Subsystems: kernel
Labels: prio:low
[Documentation on labels]
First crash: 93d, last: 93d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
f4e2939d-c23c-429e-bb2a-dd6e3f222a71 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ INFO: task hung in unwind_next_frame (2) 2026/05/19 06:02 2026/05/19 06:02 2026/05/19 06:35 9f74d39908454b73546eaf1b8211b48b66e5c0fe

			
		
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in unwind_next_frame net 1 3 693d 715d 0/29 auto-obsoleted due to no activity on 2024/11/04 07:51

Sample crash report:
INFO: task kworker/1:3:5217 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:3     state:D
 stack:21576 pid:5217  tgid:5217  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event

Call Trace:
 <TASK>
 rcu_lock_release include/linux/rcupdate.h:322 [inline]
 rcu_read_unlock include/linux/rcupdate.h:881 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0x3be/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 </TASK>
INFO: task syz.1.2230:13009 blocked for more than 172 seconds.
      Not tainted syzkaller #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2230      state:D
 stack:27432 pid:13009 tgid:13006 ppid:2967   task_flags:0x40044c flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xeb1/0x4220 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline]
 kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline]
 kobject_uevent_env+0xba8/0x18b0 lib/kobject_uevent.c:608
 device_remove+0xcb/0x180 drivers/base/dd.c:571
 __device_release_driver drivers/base/dd.c:1284 [inline]
 device_release_driver_internal+0x42e/0x600 drivers/base/dd.c:1307
 driver_detach+0xd8/0x1b0 drivers/base/dd.c:1370
 bus_remove_driver+0x13b/0x2e0 drivers/base/bus.c:784
 driver_unregister+0x76/0xb0 drivers/base/driver.c:277
 usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1751
 raw_release+0x19b/0x260 drivers/usb/gadget/legacy/raw_gadget.c:463
 __fput+0x3ff/0xb40 fs/file_table.c:469
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x8b8/0x2b60 kernel/exit.c:976
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1118
 get_signal+0x1ec7/0x21e0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x7e/0x430 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x671/0x7b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb9e923c4ab
RSP: 002b:00007fb9e7c8cf00 EFLAGS: 00000246
 ORIG_RAX: 0000000000000010
RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00007fb9e923c4ab
RDX: 00007fb9e7c8dfd0 RSI: 0000000080085502 RDI: 0000000000000003
RBP: 00007fb9e7c8dfd0 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502
R13: 0000000800000000 R14: 0000000000000000 R15: 00007fb9e92f0ede
 </TASK>
INFO: task syz.0.2229:13008 blocked for more than 173 seconds.
      Not tainted syzkaller #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2229      state:D
 stack:26536 pid:13008 tgid:13007 ppid:2972   task_flags:0x40044c flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xeb1/0x4220 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline]
 kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline]
 kobject_uevent_env+0xba8/0x18b0 lib/kobject_uevent.c:608
 device_remove+0xcb/0x180 drivers/base/dd.c:571
 __device_release_driver drivers/base/dd.c:1284 [inline]
 device_release_driver_internal+0x42e/0x600 drivers/base/dd.c:1307
 driver_detach+0xd8/0x1b0 drivers/base/dd.c:1370
 bus_remove_driver+0x13b/0x2e0 drivers/base/bus.c:784
 driver_unregister+0x76/0xb0 drivers/base/driver.c:277
 usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1751
 raw_release+0x19b/0x260 drivers/usb/gadget/legacy/raw_gadget.c:463
 __fput+0x3ff/0xb40 fs/file_table.c:469
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x8b8/0x2b60 kernel/exit.c:976
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1118
 get_signal+0x1ec7/0x21e0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x7e/0x430 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x671/0x7b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2d1f11c4ab
RSP: 002b:00007f2d1db74f00 EFLAGS: 00000246
 ORIG_RAX: 0000000000000010
RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00007f2d1f11c4ab
RDX: 00007f2d1db75fd0 RSI: 0000000080085502 RDI: 0000000000000003
RBP: 00007f2d1db75fd0 R08: 0000000000000024 R09: 00007f2d1db74fc8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502
R13: 0000000800000000 R14: 0000000000000024 R15: 00007f2d1f1d0ede
 </TASK>
INFO: task syz-executor:13018 blocked for more than 153 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D
 stack:27736 pid:13018 tgid:13018 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xeb1/0x4220 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 uevent_net_init+0x210/0x330 lib/kobject_uevent.c:794
 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
 setup_net+0x118/0x3a0 net/core/net_namespace.c:446
 copy_net_ns+0x440/0x780 net/core/net_namespace.c:581
 create_new_namespaces+0x3ea/0xc00 kernel/nsproxy.c:130
 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x473/0xad0 kernel/fork.c:3173
 __do_sys_unshare kernel/fork.c:3244 [inline]
 __se_sys_unshare kernel/fork.c:3242 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3242
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0x7b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd6d1ecdae7
RSP: 002b:00007ffdfa541908 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fd6d2145f40 RCX: 00007fd6d1ecdae7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007fd6d21467b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffdfa541b48 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:13030 blocked for more than 154 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D
 stack:27592 pid:13030 tgid:13030 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xeb1/0x4220 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 uevent_net_init+0x210/0x330 lib/kobject_uevent.c:794
 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
 setup_net+0x118/0x3a0 net/core/net_namespace.c:446
 copy_net_ns+0x440/0x780 net/core/net_namespace.c:581
 create_new_namespaces+0x3ea/0xc00 kernel/nsproxy.c:130
 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x473/0xad0 kernel/fork.c:3173
 __do_sys_unshare kernel/fork.c:3244 [inline]
 __se_sys_unshare kernel/fork.c:3242 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3242
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0x7b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f986d2adae7
RSP: 002b:00007ffe16a23af8 EFLAGS: 00000202
 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f986d525f40 RCX: 00007f986d2adae7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f986d5267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffe16a23d38 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:13032 blocked for more than 154 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D
 stack:27024 pid:13032 tgid:13032 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xeb1/0x4220 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 uevent_net_init+0x210/0x330 lib/kobject_uevent.c:794
 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
 setup_net+0x118/0x3a0 net/core/net_namespace.c:446
 copy_net_ns+0x440/0x780 net/core/net_namespace.c:581
 create_new_namespaces+0x3ea/0xc00 kernel/nsproxy.c:130
 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x473/0xad0 kernel/fork.c:3173
 __do_sys_unshare kernel/fork.c:3244 [inline]
 __se_sys_unshare kernel/fork.c:3242 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3242
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0x7b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb1e4d4dae7
RSP: 002b:00007fffcbcc5028 EFLAGS: 00000202
 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fb1e4fc5f40 RCX: 00007fb1e4d4dae7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007fb1e4fc67b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007fffcbcc5268 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:13035 blocked for more than 155 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D
 stack:27736 pid:13035 tgid:13035 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xeb1/0x4220 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 uevent_net_init+0x210/0x330 lib/kobject_uevent.c:794
 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
 setup_net+0x118/0x3a0 net/core/net_namespace.c:446
 copy_net_ns+0x440/0x780 net/core/net_namespace.c:581
 create_new_namespaces+0x3ea/0xc00 kernel/nsproxy.c:130
 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x473/0xad0 kernel/fork.c:3173
 __do_sys_unshare kernel/fork.c:3244 [inline]
 __se_sys_unshare kernel/fork.c:3242 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3242
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0x7b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff3d8f5dae7
RSP: 002b:00007ffef7f85e88 EFLAGS: 00000202
 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007ff3d91d5f40 RCX: 00007ff3d8f5dae7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007ff3d91d67b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffef7f860c8 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:13048 blocked for more than 155 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D
 stack:27720 pid:13048 tgid:13048 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xeb1/0x4220 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 uevent_net_init+0x210/0x330 lib/kobject_uevent.c:794
 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
 setup_net+0x118/0x3a0 net/core/net_namespace.c:446
 copy_net_ns+0x440/0x780 net/core/net_namespace.c:581
 create_new_namespaces+0x3ea/0xc00 kernel/nsproxy.c:130
 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x473/0xad0 kernel/fork.c:3173
 __do_sys_unshare kernel/fork.c:3244 [inline]
 __se_sys_unshare kernel/fork.c:3242 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3242
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0x7b0 arch/x86/entry/syscall_64.c:94

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/28 23:19 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 84db3719d273 b5ceaad2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in unwind_next_frame
* Struck through repros no longer work on HEAD.