INFO: task udevd:4639 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:26800 pid: 4639 ppid: 3560 flags:0x00004002
Call Trace:
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: 0033:0x7fab090666c5
RSP: 002b:00007ffea63b83b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055b569eacef0 RCX: 00007fab090666c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 000055b569e8d910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffea63b8400 R14: 0000000000000000 R15: 0000000000000000
INFO: task udevd:4732 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:27152 pid: 4732 ppid: 3560 flags:0x00004002
Call Trace:
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: 0033:0x7fab090666c5
RSP: 002b:00007ffea63b83b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055b569eb04d0 RCX: 00007fab090666c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 000055b569e8d910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffea63b8400 R14: 0000000000000000 R15: 0000000000000000
INFO: task syz-executor:4738 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:21840 pid: 4738 ppid: 4734 flags:0x00004000
Call Trace:
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: 0033:0x7f038990d7ce
RSP: 002b:00007fff7b948fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055558438a500 RCX: 00007f038990d7ce
RDX: 0000000000000001 RSI: 00007fff7b949070 RDI: 0000000000000003
RBP: 00007fff7b9495e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff7b949070 R14: 00007fff7b9495a0 R15: 00007fff7b9495e0
INFO: task syz.3.20:4952 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:25840 pid: 4952 ppid: 4736 flags:0x00004004
Call Trace:
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: 0033:0x7f684064bef9
RSP: 002b:00007ffe0f6e51b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f684064bef9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 0000000000000000 R09: 00007f684087e280
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f684087e280 R14: 0000000000000003 R15: 00007ffe0f6e5270
INFO: task syz.3.20:4953 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:24816 pid: 4953 ppid: 4736 flags:0x00004000
Call Trace:
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: 0033:0x7f684064bef9
RSP: 002b:00007f683fcaf0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f68408b6fa8 RCX: 00007f684064bef9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f68408b6fa8
RBP: 00007f68408b6fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f68408b7038 R14: 00007ffe0f6e4d90 R15: 00007ffe0f6e4e78
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 getty/3944:
#0: ffff88814ccf8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
1 lock held by udevd/4639:
#0: ffffffff8c344df0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
2 locks held by syz-executor/4723:
#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: ffff888076d7dc28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff888076d7dc28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline]
#1: ffff888076d7dc28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline]
#1: ffff888076d7dc28 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x249/0x13f0 kernel/fork.c:1518
1 lock held by syz-executor/4725:
#0: ffffffff8c344df0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
2 locks held by syz-executor/4726:
#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: ffff88807a58d528 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff88807a58d528 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline]
#1: ffff88807a58d528 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline]
#1: ffff88807a58d528 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x249/0x13f0 kernel/fork.c:1518
1 lock held by udevd/4730:
#0: ffff888076d7f828 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#0: ffff888076d7f828 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0xfa/0x240 mm/mmap.c:2949
1 lock held by udevd/4732:
#0: ffffffff8c344df0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
2 locks held by syz-executor/4733:
#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: ffff888076d7ea28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff888076d7ea28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline]
#1: ffff888076d7ea28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline]
#1: ffff888076d7ea28 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x249/0x13f0 kernel/fork.c:1518
7 locks held by syz-executor/4738:
#0: ffff88801bfaa460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
#1: ffff88805d75d888 (&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: ffff88807a58f128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#6: ffff88807a58f128 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0x33/0x2c0 mm/mempolicy.c:381
1 lock held by sed/4947:
#0: ffff888077766328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#0: ffff888077766328 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x16c/0x2d0 mm/util.c:549
1 lock held by syz.3.20/4952:
#0: ffffffff8c344df0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
1 lock held by syz.3.20/4953:
#0: ffffffff8c344df0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
=============================================
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:
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
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 1167 Comm: kworker/u4:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:__lock_acquire+0x117/0x7d10 kernel/locking/lockdep.c:4882
Code: 00 74 29 48 89 d8 48 c1 e8 03 42 80 3c 00 00 74 12 48 89 df e8 8a 3c 61 00 49 b8 00 00 00 00 00 fc ff df 48 81 3b 80 5f d4 8f <75> 03 45 31 e4 44 89 bc 24 c8 00 00 00 41 83 fe 01 77 30 44 89 f0
RSP: 0018:ffffc900049978a0 EFLAGS: 00000083
RAX: 1ffff11002d8f227 RBX: ffff888016c79138 RCX: 1ffff92000932f38
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888016c79138
RBP: ffffc90004997af0 R08: dffffc0000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1b13f06 R12: 0000000000000001
R13: ffff888022965940 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efe1e642810 CR3: 000000007f2e7000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
process_one_work+0x79b/0x1010 kernel/workqueue.c:2285
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287