INFO: task syz-executor:19295 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:19295 ppid: 19291 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:5012
 cgroup_procs_write+0x23/0x40 kernel/cgroup/cgroup.c:5052
 cgroup_file_write+0x2c3/0x660 kernel/cgroup/cgroup.c:3966
 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: 0033:0x7f0c0657658e
RSP: 002b:00007fff66061048 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00005555943a7500 RCX: 00007f0c0657658e
RDX: 0000000000000001 RSI: 00007fff660610d0 RDI: 0000000000000003
RBP: 00007fff66061640 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff660610d0 R14: 00007fff66061600 R15: 00007fff66061640
 </TASK>
INFO: task syz-executor:19297 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:21680 pid:19297 ppid: 19290 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:5012
 cgroup_procs_write+0x23/0x40 kernel/cgroup/cgroup.c:5052
 cgroup_file_write+0x2c3/0x660 kernel/cgroup/cgroup.c:3966
 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: 0033:0x7fb1873bc58e
RSP: 002b:00007ffe07471708 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00005555791e6500 RCX: 00007fb1873bc58e
RDX: 0000000000000001 RSI: 00007ffe07471790 RDI: 0000000000000003
RBP: 00007ffe07471d00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe07471790 R14: 00007ffe07471cc0 R15: 00007ffe07471d00
 </TASK>
INFO: task syz-executor:19311 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:19311 ppid: 19305 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:2597
 cgroup_attach_task+0x53e/0x7b0 kernel/cgroup/cgroup.c:2892
 __cgroup1_procs_write+0x2ee/0x3f0 kernel/cgroup/cgroup-v1.c:527
 cgroup_file_write+0x2c3/0x660 kernel/cgroup/cgroup.c:3966
 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: 0033:0x7f430bb7c58e
RSP: 002b:00007ffc161e7dd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000555569035500 RCX: 00007f430bb7c58e
RDX: 0000000000000001 RSI: 00007ffc161e7e60 RDI: 0000000000000003
RBP: 00007ffc161e83d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc161e7e60 R14: 00007ffc161e8390 R15: 00007ffc161e83d0
 </TASK>

Showing all locks held in the system:
1 lock held by kthreadd/2:
 #0: ffffffff8c3421b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: copy_process+0x22b5/0x3e20 kernel/fork.c:2382
4 locks held by kworker/u4:0/9:
 #0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc90000ce7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffffffff8d429850 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589
 #3: ffff8880434e53e8 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_destruct+0x112/0x300 drivers/net/wireguard/device.c:233
1 lock held by khungtaskd/27:
 #0: ffffffff8c31c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by klogd/3551:
2 locks held by udevd/3562:
 #0: ffffffff8c3a6810 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline]
 #0: ffffffff8c3a6810 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline]
 #0: ffffffff8c3a6810 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x22c/0x13f0 kernel/fork.c:1518
 #1: ffff88807d562428 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff88807d562428 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline]
 #1: ffff88807d562428 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline]
 #1: ffff88807d562428 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x249/0x13f0 kernel/fork.c:1518
2 locks held by getty/3949:
 #0: ffff88807f001098 (&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+0x5df/0x1a70 drivers/tty/n_tty.c:2158
1 lock held by kworker/dying/4192:
 #0: ffffffff8c3421b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:830
3 locks held by kworker/u4:7/7475:
1 lock held by napi/wg2-0/17240:
 #0: ffffffff8c3421b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:830
1 lock held by udevd/19215:
 #0: ffff88807e9f9628 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff88807e9f9628 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0xfa/0x240 mm/mmap.c:2949
2 locks held by syz-executor/19293:
 #0: ffffffff8c3a6810 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline]
 #0: ffffffff8c3a6810 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline]
 #0: ffffffff8c3a6810 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x22c/0x13f0 kernel/fork.c:1518
 #1: ffff888016c69d28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff888016c69d28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline]
 #1: ffff888016c69d28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline]
 #1: ffff888016c69d28 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x249/0x13f0 kernel/fork.c:1518
3 locks held by syz-executor/19295:
 #0: ffff88807eb62460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff88806080e888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffffffff8c341fc8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662
3 locks held by syz-executor/19297:
 #0: ffff88807eb62460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff888044c5cc88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffffffff8c341fc8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662
1 lock held by syz-executor/19302:
 #0: ffffffff8c3421b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:830
7 locks held by syz-executor/19311:
 #0: ffff88807b494460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff888044c5c888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffffffff8c341fc8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662
 #3: ffffffff8c1bae50 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2411 [inline]
 #3: ffffffff8c1bae50 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x196/0x5c0 kernel/cgroup/cgroup.c:2921
 #4: ffffffff8c3421b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2413 [inline]
 #4: ffffffff8c3421b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x1ac/0x5c0 kernel/cgroup/cgroup.c:2921
 #5: ffffffff8c34fb08 (cpuset_mutex){+.+.}-{3:3}, at: cpuset_attach+0xad/0x620 kernel/cgroup/cpuset.c:2348
 #6: ffff888016c6ab28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
 #6: ffff888016c6ab28 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0x33/0x2c0 mm/mempolicy.c:381
1 lock held by syz.3.5764/19428:
 #0: ffffffff8c3421b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:830

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

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 10/25/2025
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
CPU: 1 PID: 7475 Comm: kworker/u4:7 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
RIP: 0010:_raw_spin_lock_bh+0x2d/0x50 kernel/locking/spinlock.c:178
Code: 48 89 fb 4c 8b 74 24 10 4c 89 f7 be 01 02 00 00 e8 c8 48 85 f7 48 8d 7b 18 31 f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 41 56 <e8> be 0f 99 f7 48 83 c4 08 48 89 df 5b 41 5e e9 bf 65 9a f7 66 2e
RSP: 0018:ffffc90003fafb28 EFLAGS: 00000246
RAX: d6c6131849fafd00 RBX: ffff8880416d9880 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880416d9898
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff2037237 R12: ffff88807b210310
R13: dffffc0000000000 R14: ffffffff898f77b7 R15: ffff8880205b4050
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32e1bff8 CR3: 000000007ddb9000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 spin_lock_bh include/linux/spinlock.h:369 [inline]
 batadv_nc_purge_paths+0xe7/0x3b0 net/batman-adv/network-coding.c:446
 batadv_nc_worker+0x2e7/0x5c0 net/batman-adv/network-coding.c:724
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 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
 </TASK>