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:20336 pid: 4971 ppid:  4961 flags:0x00004000
Call Trace:
 <TASK>
 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: 0033:0x7f84988ea7ce
RSP: 002b:00007ffdbdb049f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055555c37b500 RCX: 00007f84988ea7ce
RDX: 0000000000000001 RSI: 00007ffdbdb04a80 RDI: 0000000000000003
RBP: 00007ffdbdb04ff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffdbdb04a80 R14: 00007ffdbdb04fb0 R15: 00007ffdbdb04ff0
 </TASK>
INFO: task syz-executor:4973 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:22192 pid: 4973 ppid:  4963 flags:0x00004000
Call Trace:
 <TASK>
 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: 0033:0x7fc8abfb77ce
RSP: 002b:00007ffffa726068 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00005555636dd500 RCX: 00007fc8abfb77ce
RDX: 0000000000000001 RSI: 00007ffffa7260f0 RDI: 0000000000000003
RBP: 00007ffffa726660 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffffa7260f0 R14: 00007ffffa726620 R15: 00007ffffa726660
 </TASK>
INFO: task syz.0.23:5227 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.23        state:D stack:25136 pid: 5227 ppid:  4962 flags:0x00004004
Call Trace:
 <TASK>
 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:2992
 do_exit+0x264/0x2110 kernel/exit.c:831
 do_group_exit+0x12c/0x2f0 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: 0033:0x7f5560906ef9
RSP: 002b:00007ffc9d3a4968 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5560906ef9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc9d3a49cc R08: 0000000000000000 R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 0000000000020419 R15: 00007ffc9d3a4a20
 </TASK>
INFO: task syz.0.23:5228 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.23        state:D stack:24496 pid: 5228 ppid:  4962 flags:0x00004000
Call Trace:
 <TASK>
 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:2992
 do_exit+0x264/0x2110 kernel/exit.c:831
 do_group_exit+0x12c/0x2f0 kernel/exit.c:998
 get_signal+0x7eb/0x12e0 kernel/signal.c:2901
 arch_do_signal_or_restart+0xe6/0x12a0 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: 0033:0x7f5560906ef9
RSP: 002b:00007f555ff6a0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f5560b71fa8 RCX: 00007f5560906ef9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f5560b71fa8
RBP: 00007f5560b71fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5560b72038 R14: 00007ffc9d3a4540 R15: 00007ffc9d3a4628
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31ef20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3956:
 #0: ffff88802c22f098 (&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+0x594/0x1a50 drivers/tty/n_tty.c:2158
1 lock held by syz-executor/4959:
 #0: ffffffff8c3449b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x264/0x2110 kernel/exit.c:831
2 locks held by syz-executor/4964:
 #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: ffff888076dadc28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff888076dadc28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:505 [inline]
 #1: ffff888076dadc28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1467 [inline]
 #1: ffff888076dadc28 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x247/0x13d0 kernel/fork.c:1519
2 locks held by syz-executor/4965:
 #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: ffff88805d79e328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff88805d79e328 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:505 [inline]
 #1: ffff88805d79e328 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1467 [inline]
 #1: ffff88805d79e328 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x247/0x13d0 kernel/fork.c:1519
3 locks held by syz-executor/4971:
 #0: ffff88801d7c8460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #1: ffff88805d533c88 (&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
7 locks held by syz-executor/4973:
 #0: ffff888074944460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #1: ffff88805c4dcc88 (&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: ffff888076dae328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
 #6: ffff888076dae328 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0x33/0x2c0 mm/mempolicy.c:381
2 locks held by kworker/1:10/5136:
1 lock held by udevd/5192:
 #0: ffff88802355a428 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff88802355a428 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0xf8/0x240 mm/mmap.c:2949
2 locks held by dhcpcd-run-hook/5224:
 #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: ffff88807c03ea28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff88807c03ea28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:505 [inline]
 #1: ffff88807c03ea28 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1467 [inline]
 #1: ffff88807c03ea28 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x247/0x13d0 kernel/fork.c:1519
1 lock held by syz.0.23/5227:
 #0: ffffffff8c3449b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x264/0x2110 kernel/exit.c:831
1 lock held by syz.0.23/5228:
 #0: ffffffff8c3449b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x264/0x2110 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 05/09/2026
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+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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 9 Comm: kworker/u4:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: bat_events batadv_mcast_mla_update
RIP: 0010:in_irqentry_text kernel/stacktrace.c:382 [inline]
RIP: 0010:filter_irq_stacks+0x5b/0x90 kernel/stacktrace.c:398
Code: 89 ff e8 88 9a 56 00 49 8b 04 de 48 3d e0 01 e0 89 0f 93 c1 48 3d d0 0e e0 89 0f 92 c2 84 d1 75 27 48 3d 00 00 00 8a 0f 92 c1 <48> 3d 07 00 00 8a 0f 93 c0 08 c8 74 11 48 ff c3 49 83 c7 08 49 39
RSP: 0018:ffffc90000ce7860 EFLAGS: 00000283
RAX: ffffffff815058ae RBX: 0000000000000004 RCX: 31be401c493f6701
RDX: ffffffff8dffcb01 RSI: 0000000000000006 RDI: ffffc90000ce7890
RBP: ffffc90000ce7ab0 R08: 000000000000001c R09: 0000000000000005
R10: dffffc0000000000 R11: fffff5200019cef5 R12: 0000000000000006
R13: dffffc0000000000 R14: ffffc90000ce7890 R15: ffffc90000ce78b0
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f41e8b01000 CR3: 000000001d60a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kasan_save_stack mm/kasan/common.c:39 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xb9/0xe0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:607 [inline]
 batadv_mcast_mla_softif_get_ipv6 net/batman-adv/multicast.c:446 [inline]
 batadv_mcast_mla_softif_get net/batman-adv/multicast.c:504 [inline]
 __batadv_mcast_mla_update net/batman-adv/multicast.c:878 [inline]
 batadv_mcast_mla_update+0x13c5/0x3150 net/batman-adv/multicast.c:915
 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
 </TASK>