INFO: task syz-executor.0:6209 blocked for more than 143 seconds.
Not tainted 6.16.0-rc2-syzkaller-ge04c78d86a96 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:26864 pid:6209 tgid:6208 ppid:6149 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common kernel/sched/completion.c:127 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:148
__flush_workqueue+0x6f7/0x14b0 kernel/workqueue.c:4002
nbd_start_device_ioctl drivers/block/nbd.c:1541 [inline]
__nbd_ioctl drivers/block/nbd.c:1602 [inline]
nbd_ioctl+0xafe/0xeb0 drivers/block/nbd.c:1642
blkdev_ioctl+0x5a8/0x6d0 block/ioctl.c:704
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
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: 0033:0x7fe99c87cae9
RSP: 002b:00007fe99d59e0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe99c99bf80 RCX: 00007fe99c87cae9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007fe99c8c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fe99c99bf80 R15: 00007fffd4aaf618
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13ed60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13ed60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13ed60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by kworker/u9:1/5144:
#0: ffff88802523b148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88802523b148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc9000f5dfbc0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000f5dfbc0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
2 locks held by getty/5585:
#0: ffff888030f330a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by syz-executor.0/10008:
#0: ffff888025187a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x131/0xeb0 drivers/block/nbd.c:1635
#1: ffff888142f91e00 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline]
#1: ffff888142f91e00 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: nbd_add_socket+0x1f1/0x9a0 drivers/block/nbd.c:1251
#2: ffff888142f91e38 (&q->q_usage_counter(queue)){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline]
#2: ffff888142f91e38 (&q->q_usage_counter(queue)){+.+.}-{0:0}, at: nbd_add_socket+0x1f1/0x9a0 drivers/block/nbd.c:1251
1 lock held by syz-executor.0/10009:
#0: ffff888025187a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x131/0xeb0 drivers/block/nbd.c:1635
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-ge04c78d86a96 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
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+0x70e/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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 10007 Comm: syz-executor.0 Not tainted 6.16.0-rc2-syzkaller-ge04c78d86a96 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:restore_fpregs_from_fpstate+0x0/0x150 arch/x86/kernel/fpu/core.c:161
Code: 0f ae 40 40 e9 7b ff ff ff f3 0f 1e fa e8 38 33 58 00 e9 1e fe ff ff 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <66> 0f 1f 00 41 57 41 56 41 54 53 49 89 f6 48 89 fb e8 0a 33 58 00
RSP: 0018:ffffc900052d7ea0 EFLAGS: 00000046
RAX: 1ffff11005c84aaa RBX: ffff88802e423c00 RCX: ffff88802e423c00
RDX: 0000000000000000 RSI: 00000000000e0cff RDI: ffff88802e425580
RBP: 0000000000000000 R08: ffff88802e423c07 R09: 1ffff11005c84780
R10: dffffc0000000000 R11: ffffed1005c84781 R12: dffffc0000000000
R13: 1ffff11005c84785 R14: ffff88802e425540 R15: 0000000000000000
FS: 000055557524b480(0000) GS:ffff888125c85000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557524bda8 CR3: 000000003441c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
fpregs_restore_userregs arch/x86/kernel/fpu/context.h:74 [inline]
switch_fpu_return+0x109/0x1e0 arch/x86/kernel/fpu/core.c:830
arch_exit_to_user_mode_prepare+0x2c/0x50 arch/x86/include/asm/entry-common.h:66
exit_to_user_mode_prepare include/linux/entry-common.h:332 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x177/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1ad28a7ef5
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 b9 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f ba ff ff 48 8b 04 24 48 83 c4 28 f7 d8
RSP: 002b:00007fff86d75280 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: 0000000000000000 RBX: 00007f1ad299bf80 RCX: 00007f1ad28a7ef5
RDX: 00007fff86d752c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1ad299d980 R08: 0000000000000000 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000003e504
R13: ffffffffffffffff R14: 00007f1ad2400000 R15: 000000000003e1c3