INFO: task kworker/u4:12:9185 blocked for more than 144 seconds.
Not tainted 5.15.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:12 state:D stack:24880 pid: 9185 ppid: 2 flags:0x00004000
Workqueue: nbd-del nbd_dev_remove_work
Call Trace:
context_switch kernel/sched/core.c:4969 [inline]
__schedule+0xa9a/0x4940 kernel/sched/core.c:6250
schedule+0xd2/0x260 kernel/sched/core.c:6323
blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178
del_gendisk+0x598/0x860 block/genhd.c:623
nbd_dev_remove+0x3c/0xf0 drivers/block/nbd.c:252
process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8b983b60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458
5 locks held by kworker/u4:3/57:
1 lock held by in:imklog/6213:
2 locks held by agetty/6221:
#0: ffff888022811098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252
#1: ffffc90002a2c2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113
2 locks held by kworker/u4:12/9185:
#0: ffff88801a468938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff88801a468938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff88801a468938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
#0: ffff88801a468938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline]
#0: ffff88801a468938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline]
#0: ffff88801a468938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269
#1: ffffc9000ad0fdb0 ((work_completion)(&nbd->remove_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
watchdog+0xc1d/0xf50 kernel/hung_task.c:295
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 57 Comm: kworker/u4:3 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:200
Code: 46 00 5d be 03 00 00 00 e9 86 0c 63 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 09 89 8a 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 40 70 02 00 a9
RSP: 0018:ffffc90001a3fb78 EFLAGS: 00000287
RAX: 0000000080000000 RBX: 0000000000040000 RCX: 0000000000040000
RDX: 0000000000000000 RSI: ffff8880174d5700 RDI: 0000000000000003
RBP: dffffc0000000000 R08: 00000000000113ca R09: ffffffff8fd5da87
R10: ffffffff8764e40b R11: 0000000000000001 R12: 00000000000113ca
R13: 0000000000000001 R14: ffff88807b583480 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4e22b5e740 CR3: 0000000018e40000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
get_next_corpse net/netfilter/nf_conntrack_core.c:2269 [inline]
nf_ct_iterate_cleanup+0x99/0x350 net/netfilter/nf_conntrack_core.c:2317
nf_conntrack_cleanup_net_list+0x14c/0x4f0 net/netfilter/nf_conntrack_core.c:2507
ops_exit_list+0x10d/0x160 net/core/net_namespace.c:171
cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:593
process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
----------------
Code disassembly (best guess):
0: 46 00 5d be rex.RX add %r11b,-0x42(%rbp)
4: 03 00 add (%rax),%eax
6: 00 00 add %al,(%rax)
8: e9 86 0c 63 02 jmpq 0x2630c93
d: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1)
13: 48 8b be b0 01 00 00 mov 0x1b0(%rsi),%rdi
1a: e8 b4 ff ff ff callq 0xffffffd3
1f: 31 c0 xor %eax,%eax
21: c3 retq
22: 90 nop
23: 65 8b 05 09 89 8a 7e mov %gs:0x7e8a8909(%rip),%eax # 0x7e8a8933
* 2a: 89 c1 mov %eax,%ecx <-- trapping instruction
2c: 48 8b 34 24 mov (%rsp),%rsi
30: 81 e1 00 01 00 00 and $0x100,%ecx
36: 65 48 8b 14 25 40 70 mov %gs:0x27040,%rdx
3d: 02 00
3f: a9 .byte 0xa9