INFO: task syz.0.590:9006 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.590 state:D stack:26120 pid:9006 ppid:5779 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747 sync_bdevs+0x1a4/0x320 block/bdev.c:1076 ksys_sync+0xc6/0x170 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1ec919ce59 RSP: 002b:00007f1eca10e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f1ec9415fa0 RCX: 00007f1ec919ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f1ec9415fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1ec9416038 R14: 00007f1ec9415fa0 R15: 00007ffc0b8e5038 INFO: task syz.0.590:9017 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.590 state:D stack:28856 pid:9017 ppid:5779 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747 sync_bdevs+0x1a4/0x320 block/bdev.c:1076 ksys_sync+0xc6/0x170 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1ec919ce59 RSP: 002b:00007f1eca0cc028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f1ec9416180 RCX: 00007f1ec919ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f1ec9416180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1ec9416218 R14: 00007f1ec9416180 R15: 00007ffc0b8e5038 INFO: task syz.0.590:9019 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.590 state:D stack:27640 pid:9019 ppid:5779 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747 sync_bdevs+0x1a4/0x320 block/bdev.c:1076 ksys_sync+0xc6/0x170 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1ec919ce59 RSP: 002b:00007f1eca0ab028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f1ec9416270 RCX: 00007f1ec919ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f1ec9416270 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1ec9416308 R14: 00007f1ec9416270 R15: 00007ffc0b8e5038 INFO: task syz.0.590:9021 blocked for more than 146 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.590 state:D stack:28552 pid:9021 ppid:5779 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747 sync_bdevs+0x1a4/0x320 block/bdev.c:1076 ksys_sync+0xc6/0x170 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1ec919ce59 RSP: 002b:00007f1eca08a028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f1ec9416360 RCX: 00007f1ec919ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f1ec9416360 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1ec94163f8 R14: 00007f1ec9416360 R15: 00007ffc0b8e5038 INFO: task syz.0.590:9022 blocked for more than 146 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.590 state:D stack:27832 pid:9022 ppid:5779 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747 sync_bdevs+0x1a4/0x320 block/bdev.c:1076 ksys_sync+0xc6/0x170 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1ec919ce59 RSP: 002b:00007f1eca069028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f1ec9416450 RCX: 00007f1ec919ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f1ec9416450 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1ec94164e8 R14: 00007f1ec9416450 R15: 00007ffc0b8e5038 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5536: #0: ffff888031c7a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217 1 lock held by udevd/8605: #0: ffff888140f304c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:805 1 lock held by syz.0.590/9006: #0: ffff888140f304c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1a4/0x320 block/bdev.c:1076 1 lock held by syz.0.590/9017: #0: ffff888140f304c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1a4/0x320 block/bdev.c:1076 1 lock held by syz.0.590/9019: #0: ffff888140f304c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1a4/0x320 block/bdev.c:1076 1 lock held by syz.0.590/9021: #0: ffff888140f304c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1a4/0x320 block/bdev.c:1076 1 lock held by syz.0.590/9022: #0: ffff888140f304c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1a4/0x320 block/bdev.c:1076 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 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+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf59/0xfa0 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148 Code: dc 23 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 43 67 44 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2c 89 cb 80 f9 RSP: 0018:ffffc90000187de0 EFLAGS: 000002c6 RAX: f52c0f43eb4ee200 RBX: ffffffff81628c14 RCX: f52c0f43eb4ee200 RDX: 0000000000000001 RSI: ffffffff8acacb60 RDI: ffffffff8b1c7be0 RBP: ffffc90000187f20 R08: ffff8880b8f36bab R09: 1ffff110171e6d75 R10: dffffc0000000000 R11: ffffed10171e6d76 R12: 1ffff92000030fc8 R13: dffffc0000000000 R14: 1ffff110036cd780 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055556ed20a78 CR3: 000000007c79c000 CR4: 00000000003506e0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:178 [inline] do_idle+0x334/0x5c0 kernel/sched/idle.c:302 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401 start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323 secondary_startup_64_no_verify+0x179/0x17b vkms_vblank_simulate: vblank timer overrun