INFO: task udevd:4876 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:26640 pid: 4876 ppid:  3560 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 percpu_rwsem_wait+0x2e6/0x320 kernel/locking/percpu-rwsem.c:160
 __percpu_down_read+0xc9/0x100 kernel/locking/percpu-rwsem.c:174
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:724 [inline]
 exit_signals+0x3e5/0x510 kernel/signal.c:2991
 do_exit+0x25e/0x20c0 kernel/exit.c:831
 do_group_exit+0x12e/0x300 kernel/exit.c:998
 __do_sys_exit_group kernel/exit.c:1009 [inline]
 __se_sys_exit_group kernel/exit.c:1007 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1007
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f05363476c5
RSP: 002b:00007fff0c5f9558 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000564d4c31afb0 RCX: 00007f05363476c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 0000564d4c31a910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff0c5f95a0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:4939 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:27344 pid: 4939 ppid:  4871 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 percpu_rwsem_wait+0x2e6/0x320 kernel/locking/percpu-rwsem.c:160
 __percpu_down_read+0xc9/0x100 kernel/locking/percpu-rwsem.c:174
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:724 [inline]
 exit_signals+0x3e5/0x510 kernel/signal.c:2991
 do_exit+0x25e/0x20c0 kernel/exit.c:831
 do_group_exit+0x12e/0x300 kernel/exit.c:998
 get_signal+0x6d6/0x12d0 kernel/signal.c:2900
 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f8a14448757
RSP: 002b:00007ffc81c039d0 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 0000555574a83500 RCX: 00007f8a14448757
RDX: 0000000040000000 RSI: 00007ffc81c03a2c RDI: ffffffffffffffff
RBP: 00007ffc81c03a2c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffc81c03ab0
R13: 00007ffc81c03ab8 R14: 00007f8a145a6c80 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:5043 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21968 pid: 5043 ppid:  5039 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662
 __cgroup_procs_write+0x73/0x350 kernel/cgroup/cgroup.c:5013
 cgroup_procs_write+0x23/0x40 kernel/cgroup/cgroup.c:5053
 cgroup_file_write+0x2c3/0x660 kernel/cgroup/cgroup.c:3967
 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296
 call_write_iter include/linux/fs.h:2173 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x745/0xd60 fs/read_write.c:594
 ksys_write+0x152/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f5fd8b3be0e
RSP: 002b:00007ffe35011fa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000555589958500 RCX: 00007f5fd8b3be0e
RDX: 0000000000000001 RSI: 00007ffe35012030 RDI: 0000000000000003
RBP: 00007ffe350125a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe35012030 R14: 00007ffe35012560 R15: 00007ffe350125a0
 </TASK>
INFO: task syz-executor:5050 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:21592 pid: 5050 ppid:  5046 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662
 __cgroup_procs_write+0x73/0x350 kernel/cgroup/cgroup.c:5013
 cgroup_procs_write+0x23/0x40 kernel/cgroup/cgroup.c:5053
 cgroup_file_write+0x2c3/0x660 kernel/cgroup/cgroup.c:3967
 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296
 call_write_iter include/linux/fs.h:2173 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x745/0xd60 fs/read_write.c:594
 ksys_write+0x152/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f5bc8f4ae0e
RSP: 002b:00007ffedbcb02f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000555560418500 RCX: 00007f5bc8f4ae0e
RDX: 0000000000000001 RSI: 00007ffedbcb0380 RDI: 0000000000000003
RBP: 00007ffedbcb08f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffedbcb0380 R14: 00007ffedbcb08b0 R15: 00007ffedbcb08f0
 </TASK>
INFO: task syz-executor:5053 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:21968 pid: 5053 ppid:  5042 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662
 __cgroup_procs_write+0x73/0x350 kernel/cgroup/cgroup.c:5013
 cgroup_procs_write+0x23/0x40 kernel/cgroup/cgroup.c:5053
 cgroup_file_write+0x2c3/0x660 kernel/cgroup/cgroup.c:3967
 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296
 call_write_iter include/linux/fs.h:2173 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x745/0xd60 fs/read_write.c:594
 ksys_write+0x152/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6e98f37e0e
RSP: 002b:00007ffd4412d7a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055558cea6500 RCX: 00007f6e98f37e0e
RDX: 0000000000000001 RSI: 00007ffd4412d830 RDI: 0000000000000003
RBP: 00007ffd4412dda0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffd4412d830 R14: 00007ffd4412dd60 R15: 00007ffd4412dda0
 </TASK>
INFO: task udevd:5058 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:26832 pid: 5058 ppid:  3560 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 percpu_rwsem_wait+0x2e6/0x320 kernel/locking/percpu-rwsem.c:160
 __percpu_down_read+0xc9/0x100 kernel/locking/percpu-rwsem.c:174
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:724 [inline]
 exit_signals+0x3e5/0x510 kernel/signal.c:2991
 do_exit+0x25e/0x20c0 kernel/exit.c:831
 do_group_exit+0x12e/0x300 kernel/exit.c:998
 __do_sys_exit_group kernel/exit.c:1009 [inline]
 __se_sys_exit_group kernel/exit.c:1007 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1007
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f05363476c5
RSP: 002b:00007fff0c5f9558 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000564d4c32d1a0 RCX: 00007f05363476c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 0000564d4c31a910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff0c5f95a0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:5059 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:20984 pid: 5059 ppid:  5049 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 rwsem_down_write_slowpath+0xc87/0x1260 kernel/locking/rwsem.c:1165
 mmap_write_lock include/linux/mmap_lock.h:71 [inline]
 mpol_rebind_mm+0x33/0x2c0 mm/mempolicy.c:381
 cpuset_attach+0x336/0x620 kernel/cgroup/cpuset.c:2376
 cgroup_migrate_execute+0x7eb/0x1010 kernel/cgroup/cgroup.c:2598
 cgroup_attach_task+0x53e/0x7b0 kernel/cgroup/cgroup.c:2893
 __cgroup1_procs_write+0x2ee/0x3f0 kernel/cgroup/cgroup-v1.c:527
 cgroup_file_write+0x2c3/0x660 kernel/cgroup/cgroup.c:3967
 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296
 call_write_iter include/linux/fs.h:2173 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x745/0xd60 fs/read_write.c:594
 ksys_write+0x152/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff2ac0bde0e
RSP: 002b:00007fff67b3bba8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000555566df4500 RCX: 00007ff2ac0bde0e
RDX: 0000000000000001 RSI: 00007fff67b3bc30 RDI: 0000000000000003
RBP: 00007fff67b3c1a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff67b3bc30 R14: 00007fff67b3c160 R15: 00007fff67b3c1a0
 </TASK>
INFO: task udevd:5277 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:27344 pid: 5277 ppid:  3560 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 percpu_rwsem_wait+0x2e6/0x320 kernel/locking/percpu-rwsem.c:160
 __percpu_down_read+0xc9/0x100 kernel/locking/percpu-rwsem.c:174
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:724 [inline]
 exit_signals+0x3e5/0x510 kernel/signal.c:2991
 do_exit+0x25e/0x20c0 kernel/exit.c:831
 do_group_exit+0x12e/0x300 kernel/exit.c:998
 __do_sys_exit_group kernel/exit.c:1009 [inline]
 __se_sys_exit_group kernel/exit.c:1007 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1007
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f05363476c5
RSP: 002b:00007fff0c5f9558 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000564d4c340820 RCX: 00007f05363476c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 0000564d4c31a910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff0c5f95a0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31f320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:4/1257:
 #0: ffff8880b913a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #1: ffffc90004b67d00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
1 lock held by klogd/3549:
 #0: ffff8880b913a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
2 locks held by udevd/3560:
 #0: ffffffff8c3a9410 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline]
 #0: ffffffff8c3a9410 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline]
 #0: ffffffff8c3a9410 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x22c/0x13f0 kernel/fork.c:1518
 #1: ffff88807d90d528 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff88807d90d528 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline]
 #1: ffff88807d90d528 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline]
 #1: ffff88807d90d528 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x249/0x13f0 kernel/fork.c:1518
2 locks held by getty/3951:
 #0: ffff88814cb95098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
1 lock held by udevd/4876:
 #0: ffffffff8c344df0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
1 lock held by udevd/4916:
 #0: ffff888019bbdc28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff888019bbdc28 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0xfa/0x240 mm/mmap.c:2949
1 lock held by syz-executor/4939:
 #0: ffffffff8c344df0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
3 locks held by syz-executor/5043:
 #0: ffff88801839e460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff88805d8bb488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffffffff8c344c08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662
2 locks held by syz-executor/5045:
 #0: ffffffff8c3a9410 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline]
 #0: ffffffff8c3a9410 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline]
 #0: ffffffff8c3a9410 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x22c/0x13f0 kernel/fork.c:1518
 #1: ffff8880778c1628 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff8880778c1628 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline]
 #1: ffff8880778c1628 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline]
 #1: ffff8880778c1628 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x249/0x13f0 kernel/fork.c:1518
3 locks held by syz-executor/5050:
 #0: ffff88801839e460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff88805b5a5888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffffffff8c344c08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662
3 locks held by syz-executor/5053:
 #0: ffff88801839e460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff88805a314c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffffffff8c344c08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662
1 lock held by udevd/5058:
 #0: ffffffff8c344df0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
7 locks held by syz-executor/5059:
 #0: ffff88801ecfe460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff88805b479088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffffffff8c344c08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662
 #3: ffffffff8c1bda50 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2411 [inline]
 #3: ffffffff8c1bda50 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x196/0x5c0 kernel/cgroup/cgroup.c:2922
 #4: ffffffff8c344df0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2413 [inline]
 #4: ffffffff8c344df0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x1ac/0x5c0 kernel/cgroup/cgroup.c:2922
 #5: ffffffff8c352748 (cpuset_mutex){+.+.}-{3:3}, at: cpuset_attach+0xad/0x620 kernel/cgroup/cpuset.c:2348
 #6: ffff888077c2b928 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
 #6: ffff888077c2b928 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0x33/0x2c0 mm/mempolicy.c:381
1 lock held by udevd/5274:
 #0: ffff8880777d9d28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff8880777d9d28 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0xfa/0x240 mm/mmap.c:2949
1 lock held by udevd/5277:
 #0: ffffffff8c344df0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
1 lock held by dhcpcd-run-hook/5360:
 #0: ffff88807b6ce328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff88807b6ce328 (&mm->mmap_lock){++++}-{3:3}, at: setup_arg_pages+0x2fb/0xa90 fs/exec.c:797

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729