INFO: task udevd:4777 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:26480 pid: 4777 ppid: 3559 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
percpu_rwsem_wait+0x2ca/0x300 kernel/locking/percpu-rwsem.c:160
__percpu_down_read+0xc4/0x100 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:3004
do_exit+0x264/0x2110 kernel/exit.c:837
do_group_exit+0x12c/0x2f0 kernel/exit.c:1004
__do_sys_exit_group kernel/exit.c:1015 [inline]
__se_sys_exit_group kernel/exit.c:1013 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1013
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: 0033:0x7f9c3b1496c5
RSP: 002b:00007ffddc0313b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055d9dcd8fad0 RCX: 00007f9c3b1496c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 000055d9dcd7c910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffddc031400 R14: 0000000000000000 R15: 0000000000000000
INFO: task udevd:4879 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:27088 pid: 4879 ppid: 3559 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
percpu_rwsem_wait+0x2ca/0x300 kernel/locking/percpu-rwsem.c:160
__percpu_down_read+0xc4/0x100 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:3004
do_exit+0x264/0x2110 kernel/exit.c:837
do_group_exit+0x12c/0x2f0 kernel/exit.c:1004
__do_sys_exit_group kernel/exit.c:1015 [inline]
__se_sys_exit_group kernel/exit.c:1013 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1013
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: 0033:0x7f9c3b1496c5
RSP: 002b:00007ffddc0313b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055d9dcdad2f0 RCX: 00007f9c3b1496c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 000055d9dcd7c910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffddc031400 R14: 0000000000000000 R15: 0000000000000000
INFO: task udevd:4880 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:27088 pid: 4880 ppid: 3559 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
percpu_rwsem_wait+0x2ca/0x300 kernel/locking/percpu-rwsem.c:160
__percpu_down_read+0xc4/0x100 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:3004
do_exit+0x264/0x2110 kernel/exit.c:837
do_group_exit+0x12c/0x2f0 kernel/exit.c:1004
__do_sys_exit_group kernel/exit.c:1015 [inline]
__se_sys_exit_group kernel/exit.c:1013 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1013
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: 0033:0x7f9c3b1496c5
RSP: 002b:00007ffddc0313b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055d9dcda6aa0 RCX: 00007f9c3b1496c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 000055d9dcd7c910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffddc031400 R14: 0000000000000000 R15: 0000000000000000
INFO: task syz-executor:4974 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: 4974 ppid: 4970 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 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+0xdf5/0x2400 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+0xe5/0x220 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+0x2c4/0x670 kernel/cgroup/cgroup.c:3967
kernfs_fop_write_iter+0x3a8/0x500 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2179 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x748/0xd70 fs/read_write.c:594
ksys_write+0x153/0x260 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: 0033:0x7f10a32a6e0e
RSP: 002b:00007fff4f1fc338 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055555784b500 RCX: 00007f10a32a6e0e
RDX: 0000000000000001 RSI: 00007fff4f1fc3c0 RDI: 0000000000000003
RBP: 00007fff4f1fc930 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff4f1fc3c0 R14: 00007fff4f1fc8f0 R15: 00007fff4f1fc930
INFO: task syz-executor:4978 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:21872 pid: 4978 ppid: 4972 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
rwsem_down_write_slowpath+0xe63/0x13a0 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+0x333/0x610 kernel/cgroup/cpuset.c:2381
cgroup_migrate_execute+0x7ee/0xff0 kernel/cgroup/cgroup.c:2598
cgroup_attach_task+0x593/0x830 kernel/cgroup/cgroup.c:2893
__cgroup1_procs_write+0x2ea/0x3f0 kernel/cgroup/cgroup-v1.c:527
cgroup_file_write+0x2c4/0x670 kernel/cgroup/cgroup.c:3967
kernfs_fop_write_iter+0x3a8/0x500 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2179 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x748/0xd70 fs/read_write.c:594
ksys_write+0x153/0x260 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: 0033:0x7f1914b94e0e
RSP: 002b:00007fff5e908558 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00005555702fa500 RCX: 00007f1914b94e0e
RDX: 0000000000000001 RSI: 00007fff5e9085e0 RDI: 0000000000000003
RBP: 00007fff5e908b50 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff5e9085e0 R14: 00007fff5e908b10 R15: 00007fff5e908b50
INFO: task syz-executor:4986 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:21904 pid: 4986 ppid: 4975 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 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+0xdf5/0x2400 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+0xe5/0x220 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+0x2c4/0x670 kernel/cgroup/cgroup.c:3967
kernfs_fop_write_iter+0x3a8/0x500 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2179 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x748/0xd70 fs/read_write.c:594
ksys_write+0x153/0x260 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: 0033:0x7fa63fbbce0e
RSP: 002b:00007ffc2363f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000555582316500 RCX: 00007fa63fbbce0e
RDX: 0000000000000001 RSI: 00007ffc2363f0c0 RDI: 0000000000000003
RBP: 00007ffc2363f630 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc2363f0c0 R14: 00007ffc2363f5f0 R15: 00007ffc2363f630
Showing all locks held in the system:
5 locks held by kworker/0:1/13:
#0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:475
#1: ffff8880b9027888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x4c3/0x810 kernel/sched/psi.c:882
#2: ffff8880b90280d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:946
#3: ffff88806fa934e0 (&nsim_trap_data->trap_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:364 [inline]
#3: ffff88806fa934e0 (&nsim_trap_data->trap_lock){+.+.}-{2:2}, at: nsim_dev_trap_report drivers/net/netdevsim/dev.c:707 [inline]
#3: ffff88806fa934e0 (&nsim_trap_data->trap_lock){+.+.}-{2:2}, at: nsim_dev_trap_report_work+0x198/0xab0 drivers/net/netdevsim/dev.c:762
#4: ffff88807e1a7488 (&nsim_dev->fa_cookie_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:369 [inline]
#4: ffff88807e1a7488 (&nsim_dev->fa_cookie_lock){+...}-{2:2}, at: nsim_dev_trap_report drivers/net/netdevsim/dev.c:732 [inline]
#4: ffff88807e1a7488 (&nsim_dev->fa_cookie_lock){+...}-{2:2}, at: nsim_dev_trap_report_work+0x6d3/0xab0 drivers/net/netdevsim/dev.c:762
1 lock held by khungtaskd/27:
#0: ffffffff8c31efa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3949:
#0: ffff88802d332098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
1 lock held by udevd/4777:
#0: ffffffff8c344a70 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x264/0x2110 kernel/exit.c:837
1 lock held by udevd/4879:
#0: ffffffff8c344a70 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x264/0x2110 kernel/exit.c:837
1 lock held by udevd/4880:
#0: ffffffff8c344a70 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x264/0x2110 kernel/exit.c:837
1 lock held by syz-executor/4973:
#0: ffffffff8c344a70 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x264/0x2110 kernel/exit.c:837
3 locks held by syz-executor/4974:
#0: ffff888078ba8460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
#1: ffff888024ae5888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x500 fs/kernfs/file.c:287
#2: ffffffff8c344888 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xe5/0x220 kernel/cgroup/cgroup.c:1662
2 locks held by syz-executor/4977:
#0: ffffffff8c3a9110 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:504 [inline]
#0: ffffffff8c3a9110 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1472 [inline]
#0: ffffffff8c3a9110 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x229/0x13d0 kernel/fork.c:1524
#1: ffff88805586f128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff88805586f128 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:505 [inline]
#1: ffff88805586f128 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1472 [inline]
#1: ffff88805586f128 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x247/0x13d0 kernel/fork.c:1524
7 locks held by syz-executor/4978:
#0: ffff88807869e460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
#1: ffff888024a42888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x500 fs/kernfs/file.c:287
#2: ffffffff8c344888 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xe5/0x220 kernel/cgroup/cgroup.c:1662
#3: ffffffff8c1bd670 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2411 [inline]
#3: ffffffff8c1bd670 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x196/0x5c0 kernel/cgroup/cgroup.c:2922
#4: ffffffff8c344a70 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2413 [inline]
#4: ffffffff8c344a70 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x1ac/0x5c0 kernel/cgroup/cgroup.c:2922
#5: ffffffff8c3523c8 (cpuset_mutex){+.+.}-{3:3}, at: cpuset_attach+0xad/0x610 kernel/cgroup/cpuset.c:2353
#6: ffff88807b38b928 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#6: ffff88807b38b928 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0x33/0x2c0 mm/mempolicy.c:381
2 locks held by syz-executor/4979:
#0: ffffffff8c3a9110 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:504 [inline]
#0: ffffffff8c3a9110 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1472 [inline]
#0: ffffffff8c3a9110 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x229/0x13d0 kernel/fork.c:1524
#1: ffff888025191d28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff888025191d28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:505 [inline]
#1: ffff888025191d28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1472 [inline]
#1: ffff888025191d28 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x247/0x13d0 kernel/fork.c:1524
3 locks held by syz-executor/4986:
#0: ffff888078ba8460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
#1: ffff888072bc6c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x500 fs/kernfs/file.c:287
#2: ffffffff8c344888 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xe5/0x220 kernel/cgroup/cgroup.c:1662
1 lock held by sed/5118:
#0: ffff88805586a428 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#0: ffff88805586a428 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x16c/0x2d0 mm/util.c:549
=============================================
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 09/16/2026
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+0xe1b/0xe60 kernel/hung_task.c:369
kthread+0x42e/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 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