syzbot


INFO: task hung in cgroup_can_fork (2)

Status: upstream: reported C repro on 2025/09/23 15:45
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+80596b0b7c6cb3fdc803@syzkaller.appspotmail.com
First crash: 61d, last: 1h29m
Bug presence (1)
Date Name Commit Repro Result
2025/09/24 upstream (ToT) cec1e6e5d1ab C [report] INFO: task hung in exit_mmap
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in cgroup_can_fork (2) cgroups 1 5 428d 508d 0/29 auto-obsoleted due to no activity on 2024/12/20 05:36
linux-5.15 INFO: task hung in cgroup_can_fork (2) origin:upstream 1 C 50 2h19m 73d 0/3 upstream: reported C repro on 2025/09/11 03:23
linux-6.1 INFO: task hung in cgroup_can_fork 1 1 397d 397d 0/3 auto-obsoleted due to no activity on 2025/01/30 16:24
linux-5.15 INFO: task hung in cgroup_can_fork 1 1 414d 414d 0/3 auto-obsoleted due to no activity on 2025/01/13 02:23
upstream INFO: task hung in cgroup_can_fork cgroups 1 C error error 6 1411d 1431d 0/29 auto-obsoleted due to no activity on 2023/09/02 21:24

Sample crash report:
INFO: task kworker/u4:0:9 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:0    state:D stack:26464 pid:9     ppid:2      flags:0x00004000
Workqueue: events_unbound call_usermodehelper_exec_work
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
 percpu_rwsem_wait+0x2bd/0x300 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xda/0x120 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 cgroup_css_set_fork kernel/cgroup/cgroup.c:6432 [inline]
 cgroup_can_fork+0xc27/0xd30 kernel/cgroup/cgroup.c:6565
 copy_process+0x248b/0x4020 kernel/fork.c:2446
 kernel_clone+0x225/0x8b0 kernel/fork.c:2757
 user_mode_thread+0xda/0x130 kernel/fork.c:2833
 call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
 call_usermodehelper_exec_work+0x93/0x220 kernel/umh.c:167
 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>
INFO: task udevd:4295 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:26560 pid:4295  ppid:3637   flags:0x00004002
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
 percpu_rwsem_wait+0x2bd/0x300 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xda/0x120 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 exit_signals+0x3c0/0x4f0 kernel/signal.c:2963
 do_exit+0x578/0x2400 kernel/exit.c:827
 do_group_exit+0x217/0x2d0 kernel/exit.c:1022
 __do_sys_exit_group kernel/exit.c:1033 [inline]
 __se_sys_exit_group kernel/exit.c:1031 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
 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: 0033:0x7f4b290f16c5
RSP: 002b:00007fffdc930ae8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055decd26bfb0 RCX: 00007f4b290f16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 000055decd26b910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffdc930b30 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
INFO: task udevd:4297 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:26304 pid:4297  ppid:3637   flags:0x00004002
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
 percpu_rwsem_wait+0x2bd/0x300 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xda/0x120 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 exit_signals+0x3c0/0x4f0 kernel/signal.c:2963
 do_exit+0x578/0x2400 kernel/exit.c:827
 do_group_exit+0x217/0x2d0 kernel/exit.c:1022
 __do_sys_exit_group kernel/exit.c:1033 [inline]
 __se_sys_exit_group kernel/exit.c:1031 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
 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: 0033:0x7f4b290f16c5
RSP: 002b:00007fffdc930ae8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055decd27cd60 RCX: 00007f4b290f16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 000055decd26b910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffdc930b30 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:4407 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22144 pid:4407  ppid:4402   flags:0x00004000
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
 rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
 mmap_write_lock include/linux/mmap_lock.h:71 [inline]
 mpol_rebind_mm+0xbe/0x370 mm/mempolicy.c:386
 cpuset_attach+0x284/0x540 kernel/cgroup/cpuset.c:2663
 cgroup_migrate_execute+0x7a3/0xf30 kernel/cgroup/cgroup.c:2662
 cgroup_attach_task+0x558/0x840 kernel/cgroup/cgroup.c:2953
 __cgroup1_procs_write+0x2e0/0x3e0 kernel/cgroup/cgroup-v1.c:522
 cgroup_file_write+0x2f8/0x660 kernel/cgroup/cgroup.c:4100
 kernfs_fop_write_iter+0x3b2/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x44c/0x960 fs/read_write.c:584
 ksys_write+0x143/0x240 fs/read_write.c:637
 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: 0033:0x7f5dc498e1ff
RSP: 002b:00007ffc4f905020 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f5dc498e1ff
RDX: 0000000000000001 RSI: 00007ffc4f905070 RDI: 0000000000000003
RBP: 00007ffc4f9055e0 R08: 0000000000000000 R09: 00007ffc4f904e77
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007ffc4f905070 R14: 00007ffc4f9055a0 R15: 00007ffc4f9055e0
 </TASK>
INFO: task kworker/u4:6:4436 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:6    state:D stack:26056 pid:4436  ppid:2      flags:0x00004000
Workqueue: events_unbound call_usermodehelper_exec_work
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
 percpu_rwsem_wait+0x2bd/0x300 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xda/0x120 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 cgroup_css_set_fork kernel/cgroup/cgroup.c:6432 [inline]
 cgroup_can_fork+0xc27/0xd30 kernel/cgroup/cgroup.c:6565
 copy_process+0x248b/0x4020 kernel/fork.c:2446
 kernel_clone+0x225/0x8b0 kernel/fork.c:2757
 user_mode_thread+0xda/0x130 kernel/fork.c:2833
 call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
 call_usermodehelper_exec_work+0x93/0x220 kernel/umh.c:167
 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>
INFO: task syz.0.17:4533 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:25728 pid:4533  ppid:4405   flags:0x00004000
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
 percpu_rwsem_wait+0x2bd/0x300 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xda/0x120 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 exit_signals+0x3c0/0x4f0 kernel/signal.c:2963
 do_exit+0x578/0x2400 kernel/exit.c:827
 do_group_exit+0x217/0x2d0 kernel/exit.c:1022
 __do_sys_exit_group kernel/exit.c:1033 [inline]
 __se_sys_exit_group kernel/exit.c:1031 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
 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: 0033:0x7f70c058f749
RSP: 002b:00007ffd7235a0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f70c058f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 000000057235a1ef R09: 00007f70c07b4280
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f70c07b4280 R14: 0000000000000003 R15: 00007ffd7235a1b0
 </TASK>
INFO: task syz.1.25:4534 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.25        state:D stack:25320 pid:4534  ppid:4404   flags:0x00004000
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
 percpu_rwsem_wait+0x2bd/0x300 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xda/0x120 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline]
 exit_signals+0x3c0/0x4f0 kernel/signal.c:2963
 do_exit+0x578/0x2400 kernel/exit.c:827
 do_group_exit+0x217/0x2d0 kernel/exit.c:1022
 __do_sys_exit_group kernel/exit.c:1033 [inline]
 __se_sys_exit_group kernel/exit.c:1031 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
 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: 0033:0x7fa35bb8f749
RSP: 002b:00007fff248f6b08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa35bb8f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fff248f6b6c R08: 00000005248f6bff R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000004
R13: 00000000000927c0 R14: 000000000002baaa R15: 00007fff248f6bc0
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u4:0/9:
 #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc900000e7d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8cb538d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: copy_process+0x248b/0x4020 kernel/fork.c:2446
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8cb2b630 (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: ffffffff8cb2be50 (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/27:
 #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
3 locks held by kworker/u4:4/56:
 #0: ffff8880b8e3aad8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
 #1: ffff8880b8e27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x398/0x6d0 kernel/sched/psi.c:999
 #2: ffffffff8c9c7b30 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_enable+0xe/0x20 kernel/jump_label.c:219
1 lock held by dhcpcd/3932:
 #0: ffffffff8cb538d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: copy_process+0x248b/0x4020 kernel/fork.c:2446
2 locks held by getty/4026:
 #0: ffff88814d2dc098 (&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
1 lock held by udevd/4295:
 #0: ffffffff8cb538d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x578/0x2400 kernel/exit.c:827
1 lock held by udevd/4297:
 #0: ffffffff8cb538d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x578/0x2400 kernel/exit.c:827
1 lock held by syz-executor/4400:
 #0: ffffffff8cb538d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x578/0x2400 kernel/exit.c:827
7 locks held by syz-executor/4407:
 #0: ffff88801ce68460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580
 #1: ffff88802906ec88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
 #2: ffffffff8cb536e8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:442 [inline]
 #2: ffffffff8cb536e8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1700
 #3: ffffffff8c9c7b30 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2476 [inline]
 #3: ffffffff8c9c7b30 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x183/0x600 kernel/cgroup/cgroup.c:2982
 #4: ffffffff8cb538d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2478 [inline]
 #4: ffffffff8cb538d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x199/0x600 kernel/cgroup/cgroup.c:2982
 #5: ffffffff8cb61d68 (cpuset_mutex){+.+.}-{3:3}, at: cpuset_attach+0xac/0x540 kernel/cgroup/cpuset.c:2647
 #6: ffff88801746bd58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
 #6: ffff88801746bd58 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0xbe/0x370 mm/mempolicy.c:386
3 locks held by kworker/u4:6/4436:
 #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90003507d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #2: ffffffff8cb538d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: copy_process+0x248b/0x4020 kernel/fork.c:2446
1 lock held by syz.0.17/4533:
 #0: ffffffff8cb538d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x578/0x2400 kernel/exit.c:827
1 lock held by syz.1.25/4534:
 #0: ffffffff8cb538d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x578/0x2400 kernel/exit.c:827

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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: 56 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3719 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3738 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3793 [inline]
RIP: 0010:__lock_acquire+0x171c/0x7c50 kernel/locking/lockdep.c:5049
Code: ff ff ff 4c 8d 73 18 4c 89 f0 48 c1 e8 03 42 80 3c 00 00 74 12 4c 89 f7 e8 e1 f0 6d 00 49 b8 00 00 00 00 00 fc ff df 49 8b 06 <4c> 8b b4 24 90 00 00 00 4c 39 f0 0f 84 3b 02 00 00 48 83 c3 08 48
RSP: 0018:ffffc900015774e0 EFLAGS: 00000046
RAX: 42f39a3757dade16 RBX: ffffffff90ae5c80 RCX: ffffffff81631100
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90ae2240
RBP: ffffc90001577730 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: ffffffff90751968
R13: 0000000075a1531d R14: ffffffff90ae5c98 R15: ffff88801d6e4650
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558ec735c8 CR3: 000000000c88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
 debug_object_assert_init+0x98/0x2f0 lib/debugobjects.c:887
 debug_timer_assert_init kernel/time/timer.c:792 [inline]
 debug_assert_init kernel/time/timer.c:837 [inline]
 __mod_timer+0x54/0xd00 kernel/time/timer.c:1020
 queue_delayed_work_on+0x126/0x1e0 kernel/workqueue.c:1704
 queue_delayed_work include/linux/workqueue.h:527 [inline]
 toggle_allocation_gate+0x3d6/0x430 mm/kfence/core.c:821
 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 (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/23 15:39 linux-6.1.y f6e38ae624cf 4fb8ef37 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in cgroup_can_fork
2025/10/09 01:39 linux-6.1.y 882efbdd9d34 7e2882b3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in cgroup_can_fork
2025/10/04 18:09 linux-6.1.y 882efbdd9d34 49379ee0 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in cgroup_can_fork
2025/10/04 01:39 linux-6.1.y 882efbdd9d34 49379ee0 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in cgroup_can_fork
2025/10/03 14:58 linux-6.1.y 882efbdd9d34 49379ee0 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in cgroup_can_fork
2025/10/01 09:40 linux-6.1.y 7b34dc04e4ff 65a0eece .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in cgroup_can_fork
2025/09/23 15:44 linux-6.1.y 363a599da6d9 0ac7291c .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in cgroup_can_fork
2025/10/31 09:26 linux-6.1.y f6e38ae624cf 2c50b6a9 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in cgroup_can_fork
2025/09/24 22:34 linux-6.1.y 363a599da6d9 0abd0691 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in cgroup_can_fork
* Struck through repros no longer work on HEAD.