INFO: task syz.2.310:7574 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.310       state:D stack:27656 pid:7574  tgid:7573  ppid:5858   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5401 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6790
 __schedule_loop kernel/sched/core.c:6868 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6883
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6940
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
 sync_bdevs+0x1ac/0x340 block/bdev.c:1288
 ksys_sync+0xb9/0x150 fs/sync.c:105
 __ia32_sys_sync+0xe/0x20 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe97298e929
RSP: 002b:00007fe9707f6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fe972bb5fa0 RCX: 00007fe97298e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fe972bb5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe972bb5fa0 R15: 00007fffe5ad84d8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5602:
 #0: ffff88814c51b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/6088:
 #0: ffff888142fbe358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
1 lock held by syz.2.310/7574:
 #0: ffff888142fbe358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5830 Comm: syz-executor Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline]
RIP: 0010:syscall_exit_to_user_mode_work include/linux/entry-common.h:400 [inline]
RIP: 0010:syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
RIP: 0010:do_syscall_64+0x11d/0x3b0 arch/x86/entry/syscall_64.c:100
Code: 89 f7 e8 d6 9e c4 f5 49 89 46 50 90 90 4d 8b 67 08 4c 89 f7 e8 94 c0 c4 f5 0f 1f 44 00 00 48 c7 43 08 00 00 00 00 9c 8f 43 08 <f7> 43 08 00 02 00 00 0f 84 53 01 00 00 41 f6 c4 76 0f 85 6e 01 00
RSP: 0018:ffffc900043cfef0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc900043cfef0 RCX: ffff888021305a00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc900043cff58
RBP: ffffc900043cff48 R08: ffffc900043cfd97 R09: 1ffff92000879fb2
R10: dffffc0000000000 R11: fffff52000879fb3 R12: 0000000000000000
R13: 0000000000000000 R14: ffffc900043cff58 R15: ffff888021305a00
FS:  000055557f769500(0000) GS:ffff888125d1d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffa84981ab8 CR3: 000000007b458000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0efdb8d2fd
Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb b5 e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d 41 92 1f 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec
RSP: 002b:00007ffc75992558 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f0efdb8d2fd
RDX: 0000000000000004 RSI: 00007ffc7599256c RDI: 0000000000000003
RBP: 0000000000000000 R08: 000000003466220f R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc75992980
R13: 0000000000000004 R14: 00007ffc7599256c R15: 00007ffc75992600
 </TASK>