INFO: task syz-executor:4962 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:22112 pid: 4962 ppid: 4959 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:2376
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:2173 [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: 0033:0x7fb5578457ce
RSP: 002b:00007fffd8cfb9e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055555f287500 RCX: 00007fb5578457ce
RDX: 0000000000000001 RSI: 00007fffd8cfba70 RDI: 0000000000000003
RBP: 00007fffd8cfbfe0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fffd8cfba70 R14: 00007fffd8cfbfa0 R15: 00007fffd8cfbfe0
INFO: task syz-executor:4970 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:21168 pid: 4970 ppid: 4958 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:2173 [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: 0033:0x7f7971ab07ce
RSP: 002b:00007ffe04694338 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055557e519500 RCX: 00007f7971ab07ce
RDX: 0000000000000001 RSI: 00007ffe046943c0 RDI: 0000000000000003
RBP: 00007ffe04694930 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe046943c0 R14: 00007ffe046948f0 R15: 00007ffe04694930
INFO: task syz-executor:4971 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:18448 pid: 4971 ppid: 4961 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:2173 [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: 0033:0x7f8c0b54b7ce
RSP: 002b:00007fffb3a21418 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055555a859500 RCX: 00007f8c0b54b7ce
RDX: 0000000000000001 RSI: 00007fffb3a214a0 RDI: 0000000000000003
RBP: 00007fffb3a21a10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fffb3a214a0 R14: 00007fffb3a219d0 R15: 00007fffb3a21a10
Showing all locks held in the system:
3 locks held by kworker/u4:0/9:
1 lock held by khungtaskd/27:
#0: ffffffff8c31ef20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by klogd/3546:
#0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:475
2 locks held by getty/3941:
#0: ffff88802c207098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
1 lock held by syz-executor/4955:
#0: ffffffff8c3449b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x264/0x2110 kernel/exit.c:831
2 locks held by syz-executor/4957:
#0: ffffffff8c3a8ed0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:504 [inline]
#0: ffffffff8c3a8ed0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1467 [inline]
#0: ffffffff8c3a8ed0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x229/0x13d0 kernel/fork.c:1519
#1: ffff8880759ab928 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff8880759ab928 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:505 [inline]
#1: ffff8880759ab928 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1467 [inline]
#1: ffff8880759ab928 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x247/0x13d0 kernel/fork.c:1519
2 locks held by syz-executor/4960:
#0: ffffffff8c3a8ed0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:504 [inline]
#0: ffffffff8c3a8ed0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1467 [inline]
#0: ffffffff8c3a8ed0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x229/0x13d0 kernel/fork.c:1519
#1: ffff8880759aab28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff8880759aab28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:505 [inline]
#1: ffff8880759aab28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1467 [inline]
#1: ffff8880759aab28 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x247/0x13d0 kernel/fork.c:1519
7 locks held by syz-executor/4962:
#0: ffff88801f100460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
#1: ffff8880241d8488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x500 fs/kernfs/file.c:287
#2: ffffffff8c3447c8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xe5/0x220 kernel/cgroup/cgroup.c:1662
#3: ffffffff8c1bd6f0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2411 [inline]
#3: ffffffff8c1bd6f0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x196/0x5c0 kernel/cgroup/cgroup.c:2922
#4: ffffffff8c3449b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2413 [inline]
#4: ffffffff8c3449b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x1ac/0x5c0 kernel/cgroup/cgroup.c:2922
#5: ffffffff8c352308 (cpuset_mutex){+.+.}-{3:3}, at: cpuset_attach+0xad/0x610 kernel/cgroup/cpuset.c:2348
#6: ffff8880759aa428 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#6: ffff8880759aa428 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0x33/0x2c0 mm/mempolicy.c:381
3 locks held by syz-executor/4970:
#0: ffff88801dd50460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
#1: ffff88805a3dfc88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x500 fs/kernfs/file.c:287
#2: ffffffff8c3447c8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xe5/0x220 kernel/cgroup/cgroup.c:1662
3 locks held by syz-executor/4971:
#0: ffff88801dd50460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
#1: ffff888058cb2088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x500 fs/kernfs/file.c:287
#2: ffffffff8c3447c8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xe5/0x220 kernel/cgroup/cgroup.c:1662
1 lock held by udevd/5241:
#0: ffff88807799dc28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#0: ffff88807799dc28 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0xf8/0x240 mm/mmap.c:2949
1 lock held by sed/5261:
#0: ffff88807d9b8128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#0: ffff88807d9b8128 (&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 05/09/2026
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
CPU: 1 PID: 154 Comm: kworker/u4:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__this_cpu_preempt_check+0x0/0x10 lib/smp_processor_id.c:65
Code: 48 89 da e8 b2 4a f5 ff 48 8b 74 24 30 48 c7 c7 c0 2a 7a 8a e8 a1 4a f5 ff e8 fc 04 f8 ff eb a8 e8 d5 ee ff ff 0f 1f 44 00 00 <48> 89 fe 48 c7 c7 40 2a 7a 8a e9 e1 fe ff ff 00 eb 1e 0f 1f 00 48
RSP: 0018:ffffc900020579f8 EFLAGS: 00000086
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff815cf12c
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8a2b3e80
RBP: ffffc90002057b20 R08: dffffc0000000000 R09: 1ffffffff203d238
R10: dffffc0000000000 R11: fffffbfff203d239 R12: ffff888074115898
R13: 1ffff9200040af4c R14: 0000000000000246 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb557752d80 CR3: 000000007e239000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline]
lock_acquire+0x1ae/0x400 kernel/locking/lockdep.c:5625
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x32/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:369 [inline]
batadv_nc_purge_paths+0xe2/0x3a0 net/batman-adv/network-coding.c:446
batadv_nc_worker+0x321/0x5c0 net/batman-adv/network-coding.c:726
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287