INFO: task syz.1.1020:12056 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1020 state:D stack:27176 pid:12056 tgid:12044 ppid:10419 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5340 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
sync_bdevs+0x27e/0x470 block/bdev.c:1304
ksys_sync fs/sync.c:105 [inline]
__ia32_sys_sync+0xc5/0x120 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2d6d19bf79
RSP: 002b:00007f2d6afb2028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f2d6d416270 RCX: 00007f2d6d19bf79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f2d6d416270 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2d6d416308 R14: 00007f2d6d416270 R15: 00007fff535453e8
Showing all locks held in the system:
3 locks held by kworker/0:1/10:
#0: ffff88801b06b548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc900000f7c40 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#2: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
1 lock held by khungtaskd/31:
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5582:
#0: ffff8880368630a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:3/5913:
#0: ffff88802229d548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc90004867c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffff88802a6b5198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff88802a6b5198 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
1 lock held by udevd/7217:
#0: ffff88802734e358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by syz.1.1020/12056:
#0: ffff88802734e358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1304
1 lock held by syz.4.1071/12424:
#0: ffff88802734e358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1304
2 locks held by syz.6.1289/13655:
2 locks held by syz.6.1306/13736:
1 lock held by sed/13803:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 13780 Comm: syz.3.1317 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:unix_copy_addr net/unix/af_unix.c:2544 [inline]
RIP: 0010:__unix_dgram_recvmsg+0x50d/0xd50 net/unix/af_unix.c:2601
Code: be 78 05 00 00 4c 03 33 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 f7 e8 16 5f e4 f7 49 8b 1e <48> 85 db 0f 84 94 00 00 00 e8 55 37 7a f7 4c 8d 73 04 4c 89 f0 48
RSP: 0018:ffffc900106cf700 EFLAGS: 00000246
RAX: 1ffff110065dccb7 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffffc90010c1a000 RSI: 000000000007ffff RDI: ffffc900106cfce0
RBP: ffffc900106cf870 R08: ffffffff901195b7 R09: 1ffffffff20232b6
R10: dffffc0000000000 R11: fffffbfff20232b7 R12: ffff888032adc140
R13: 1ffff920020d9f9c R14: ffff888032ee65b8 R15: ffff888036455780
FS: 00007fcfb83b46c0(0000) GS:ffff888125460000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000388030 CR3: 0000000053332000 CR4: 00000000003526f0
DR0: 000000000000afe8 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
sock_recvmsg_nosec+0x186/0x1c0 net/socket.c:1093
____sys_recvmsg+0x245/0x510 net/socket.c:-1
___sys_recvmsg+0x215/0x590 net/socket.c:2872
do_recvmmsg+0x334/0x800 net/socket.c:2967
__sys_recvmmsg net/socket.c:3041 [inline]
__do_sys_recvmmsg net/socket.c:3064 [inline]
__se_sys_recvmmsg net/socket.c:3057 [inline]
__x64_sys_recvmmsg+0x198/0x250 net/socket.c:3057
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcfb759bf79
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcfb83b4028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fcfb7815fa0 RCX: 00007fcfb759bf79
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007fcfb76327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcfb7816038 R14: 00007fcfb7815fa0 R15: 00007fffd0182658