INFO: task syz.0.5299:26778 blocked for more than 144 seconds.
Not tainted 6.14.0-rc4-syzkaller-00199-g76544811c850 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.5299 state:D stack:27232 pid:26778 tgid:26771 ppid:16467 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5378 [inline]
__schedule+0x18bc/0x4c40 kernel/sched/core.c:6765
__schedule_loop kernel/sched/core.c:6842 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6857
schedule_timeout+0xb0/0x290 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+0x355/0x620 kernel/sched/completion.c:148
__flush_workqueue+0x575/0x1280 kernel/workqueue.c:4000
nbd_start_device_ioctl drivers/block/nbd.c:1541 [inline]
__nbd_ioctl drivers/block/nbd.c:1602 [inline]
nbd_ioctl+0xbd1/0xf40 drivers/block/nbd.c:1642
blkdev_ioctl+0x5d0/0x6f0 block/ioctl.c:693
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9abd58d169
RSP: 002b:00007f9abb3f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f9abd7a6080 RCX: 00007f9abd58d169
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004
RBP: 00007f9abd60e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f9abd7a6080 R15: 00007ffc9c5abea8
Showing all locks held in the system:
1 lock held by rcu_exp_gp_kthr/19:
1 lock held by khungtaskd/30:
#0: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#0: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
2 locks held by getty/5582:
#0: ffff888035a790a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211
2 locks held by kworker/u9:3/5823:
#0: ffff888025f03148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff888025f03148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
#1: ffffc900042cfc60 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc900042cfc60 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
1 lock held by syz-executor/10076:
#0: ffffffff8eb3e478 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline]
#0: ffffffff8eb3e478 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:996
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc4-syzkaller-00199-g76544811c850 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
watchdog+0x1058/0x10a0 kernel/hung_task.c:399
kthread+0x7a9/0x920 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5807 Comm: syz-executor Not tainted 6.14.0-rc4-syzkaller-00199-g76544811c850 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:tcp_recvmsg_locked+0x30/0x3a80 net/ipv4/tcp.c:2573
Code: 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 03 00 00 4c 89 8c 24 a8 01 00 00 4c 89 84 24 68 01 00 00 89 4c 24 44 <48> 89 94 24 a8 00 00 00 48 89 b4 24 a0 00 00 00 48 89 fb 65 48 8b
RSP: 0018:ffffc9000411f520 EFLAGS: 00000282
RAX: 4500023686446000 RBX: ffffc9000411f9d0 RCX: 0000000000000040
RDX: 0000000000000004 RSI: ffffc9000411fbc0 RDI: ffff88807b1b9980
RBP: ffffc9000411f930 R08: ffffc9000411f9d0 R09: ffffc9000411f9c0
R10: dffffc0000000000 R11: fffffbfff28a2722 R12: dffffc0000000000
R13: ffff88807b1b9980 R14: ffffc9000411f9c0 R15: ffffc9000411fbc0
FS: 0000555576806500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f65d8778ab8 CR3: 0000000078b6a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
tcp_recvmsg+0x25d/0x920 net/ipv4/tcp.c:2865
inet_recvmsg+0x150/0x2d0 net/ipv4/af_inet.c:883
sock_recvmsg_nosec net/socket.c:1023 [inline]
sock_recvmsg+0x1ae/0x280 net/socket.c:1045
sock_read_iter+0x2c4/0x3d0 net/socket.c:1115
new_sync_read fs/read_write.c:484 [inline]
vfs_read+0x975/0xb40 fs/read_write.c:565
ksys_read+0x18f/0x2b0 fs/read_write.c:708
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd4d258bb3d
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 01 1a 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:00007fff0906fee8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd4d258bb3d
RDX: 0000000000000004 RSI: 00007fff0906fefc RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000030fddcc8 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff09070310
R13: 0000000000000004 R14: 00007fff0906fefc R15: 00007fff0906ff90