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:21968 pid: 4970 ppid:  4968 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:5013
 cgroup_procs_write+0x23/0x40 kernel/cgroup/cgroup.c:5053
 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: 0033:0x7f4d1a4d7e0e
RSP: 002b:00007ffff22b7308 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055558f7d9500 RCX: 00007f4d1a4d7e0e
RDX: 0000000000000001 RSI: 00007ffff22b7390 RDI: 0000000000000003
RBP: 00007ffff22b7900 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffff22b7390 R14: 00007ffff22b78c0 R15: 00007ffff22b7900
 </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:21808 pid: 4973 ppid:  4969 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: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: 0033:0x7ff7d8a41e0e
RSP: 002b:00007fff60d2fa78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055555e81c500 RCX: 00007ff7d8a41e0e
RDX: 0000000000000001 RSI: 00007fff60d2fb00 RDI: 0000000000000003
RBP: 00007fff60d30070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff60d2fb00 R14: 00007fff60d30030 R15: 00007fff60d30070
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31f360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3951:
 #0: ffff88807f608098 (&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
3 locks held by syz-executor/4970:
 #0: ffff88801e440460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff888058a12488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffffffff8c344c48 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662
7 locks held by syz-executor/4973:
 #0: ffff8880767ea460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590
 #1: ffff888058a14888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
 #2: ffffffff8c344c48 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1662
 #3: ffffffff8c1bda90 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2411 [inline]
 #3: ffffffff8c1bda90 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x196/0x5c0 kernel/cgroup/cgroup.c:2922
 #4: ffffffff8c344e30 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2413 [inline]
 #4: ffffffff8c344e30 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x1ac/0x5c0 kernel/cgroup/cgroup.c:2922
 #5: ffffffff8c352788 (cpuset_mutex){+.+.}-{3:3}, at: cpuset_attach+0xad/0x620 kernel/cgroup/cpuset.c:2348
 #6: ffff888026180f28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
 #6: ffff888026180f28 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0x33/0x2c0 mm/mempolicy.c:381
1 lock held by syz-executor/4974:
 #0: ffffffff8c344e30 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
2 locks held by syz-executor/4976:
 #0: ffffffff8c3a9450 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline]
 #0: ffffffff8c3a9450 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline]
 #0: ffffffff8c3a9450 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x22c/0x13f0 kernel/fork.c:1518
 #1: ffff8880773e7128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff8880773e7128 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline]
 #1: ffff8880773e7128 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline]
 #1: ffff8880773e7128 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x249/0x13f0 kernel/fork.c:1518
2 locks held by syz-executor/4980:
 #0: ffffffff8c3a9450 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline]
 #0: ffffffff8c3a9450 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline]
 #0: ffffffff8c3a9450 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x22c/0x13f0 kernel/fork.c:1518
 #1: ffff8880773e3228 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff8880773e3228 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline]
 #1: ffff8880773e3228 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline]
 #1: ffff8880773e3228 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x249/0x13f0 kernel/fork.c:1518
2 locks held by syz-executor/4982:
 #0: ffffffff8c3a9450 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline]
 #0: ffffffff8c3a9450 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline]
 #0: ffffffff8c3a9450 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x22c/0x13f0 kernel/fork.c:1518
 #1: ffff888026180128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #1: ffff888026180128 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline]
 #1: ffff888026180128 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline]
 #1: ffff888026180128 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x249/0x13f0 kernel/fork.c:1518
1 lock held by udevd/5015:
 #0: ffffffff8c344e30 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
1 lock held by udevd/5016:
 #0: ffffffff8c344e30 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
1 lock held by udevd/5017:
 #0: ffffffff8c344e30 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
1 lock held by udevd/5076:
 #0: ffffffff8c344e30 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x25e/0x20c0 kernel/exit.c:831
1 lock held by sed/5261:
 #0: ffff88805a514728 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff88805a514728 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x16c/0x2d0 mm/util.c:549

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

NMI backtrace for cpu 1
CPU: 1 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+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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3549 Comm: klogd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:unix_dgram_sendmsg+0x11e4/0x18a0 net/unix/af_unix.c:1946
Code: 89 f7 4c 89 ee e8 3c ce ff ff 49 8d be b0 01 00 00 4c 89 ee e8 4d 1e 45 ff 48 8b 7c 24 50 e8 b3 ab 2d 01 49 8d be c8 04 00 00 <48> 89 f8 48 c1 e8 03 42 80 3c 38 00 74 05 e8 99 25 25 f9 4c 89 f7
RSP: 0018:ffffc90002d9fb40 EFLAGS: 00000286
RAX: 0000000080000000 RBX: ffffc90002d9fc50 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807e8624c8
RBP: ffffc90002d9fcf0 R08: ffff88807e86267b R09: 1ffff1100fd0c4cf
R10: dffffc0000000000 R11: ffffed100fd0c4d0 R12: 1ffff920005b3f84
R13: ffff88805a8e8000 R14: ffff88807e862000 R15: dffffc0000000000
FS:  00007fdb79ee2c80(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4e0e0df200 CR3: 000000002b47b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 __sys_sendto+0x46d/0x620 net/socket.c:2072
 __do_sys_sendto net/socket.c:2084 [inline]
 __se_sys_sendto net/socket.c:2080 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2080
 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: 0033:0x7fdb7a032407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffca1cb5cf0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fdb79ee2c80 RCX: 00007fdb7a032407
RDX: 0000000000000046 RSI: 00007ffca1cb5e30 RDI: 0000000000000003
RBP: 00007ffca1cb6260 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffca1cb6278
R13: 00007ffca1cb5e30 R14: 000000000000002b R15: 00007ffca1cb5e30
 </TASK>