syzbot

INFO: task syz-executor.3:19132 blocked for more than 143 seconds.
      Not tainted 5.17.0-rc2-syzkaller-00398-gd8ad2ce873ab #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:28512 pid:19132 ppid:  3622 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4986 [inline]
 __schedule+0xab2/0x4db0 kernel/sched/core.c:6295
 schedule+0xd2/0x260 kernel/sched/core.c:6368
 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178
 nbd_add_socket+0x166/0x810 drivers/block/nbd.c:1109
 __nbd_ioctl drivers/block/nbd.c:1454 [inline]
 nbd_ioctl+0x38c/0xb10 drivers/block/nbd.c:1511
 blkdev_ioctl+0x37a/0x800 block/ioctl.c:588
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f3a2fd75059
RSP: 002b:00007f3a2e6a8168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f3a2fe88100 RCX: 00007f3a2fd75059
RDX: 0000000000000006 RSI: 000000000000ab00 RDI: 0000000000000003
RBP: 00007f3a2fdcf08d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff2b26772f R14: 00007f3a2e6a8300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8bb83c20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6460
2 locks held by kworker/u4:4/999:
 #0: ffff8880b9d39c58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:489
 #1: ffff8880b9d27948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3e7/0x4e0 kernel/sched/psi.c:891
2 locks held by getty/3276:
 #0: ffff88802303f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244
 #1: ffffc90002b632e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2077
1 lock held by syz-executor.3/19132:
 #0: ffff88801a753998 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x151/0xb10 drivers/block/nbd.c:1504

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.17.0-rc2-syzkaller-00398-gd8ad2ce873ab #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __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:111
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xc1d/0xf50 kernel/hung_task.c:369
 kthread+0x2e9/0x3a0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8389 Comm: kworker/u4:18 Not tainted 5.17.0-rc2-syzkaller-00398-gd8ad2ce873ab #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:lock_acquire+0x69/0x510 kernel/locking/lockdep.c:5607
Code: 03 48 c7 44 24 18 12 d6 39 8b 48 01 d8 48 c7 44 24 20 50 5a 5d 81 c7 00 f1 f1 f1 f1 c7 40 04 f1 f1 00 00 c7 40 08 00 00 00 f3 <c7> 40 0c f3 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 84 24 a8 00
RSP: 0018:ffffc9000499fab0 EFLAGS: 00000282
RAX: fffff52000933f58 RBX: 1ffff92000933f58 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8bb83c20
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff88e1b846 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: ffffffff8bb83c20 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c000041da8 CR3: 0000000071913000 CR4: 0000000000350ee0
Call Trace:
 <TASK>
 rcu_lock_acquire include/linux/rcupdate.h:268 [inline]
 rcu_read_lock include/linux/rcupdate.h:694 [inline]
 batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:755 [inline]
 batadv_iv_ogm_schedule_buff+0x5d2/0x1430 net/batman-adv/bat_iv_ogm.c:826
 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:869 [inline]
 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:862 [inline]
 batadv_iv_send_outstanding_bat_ogm_packet+0x740/0x910 net/batman-adv/bat_iv_ogm.c:1713
 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307
 worker_thread+0x657/0x1110 kernel/workqueue.c:2454
 kthread+0x2e9/0x3a0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
----------------
Code disassembly (best guess):
   0:	03 48 c7             	add    -0x39(%rax),%ecx
   3:	44 24 18             	rex.R and $0x18,%al
   6:	12 d6                	adc    %dh,%dl
   8:	39 8b 48 01 d8 48    	cmp    %ecx,0x48d80148(%rbx)
   e:	c7 44 24 20 50 5a 5d 	movl   $0x815d5a50,0x20(%rsp)
  15:	81
  16:	c7 00 f1 f1 f1 f1    	movl   $0xf1f1f1f1,(%rax)
  1c:	c7 40 04 f1 f1 00 00 	movl   $0xf1f1,0x4(%rax)
  23:	c7 40 08 00 00 00 f3 	movl   $0xf3000000,0x8(%rax)
* 2a:	c7 40 0c f3 f3 f3 f3 	movl   $0xf3f3f3f3,0xc(%rax) <-- trapping instruction
  31:	65 48 8b 04 25 28 00 	mov    %gs:0x28,%rax
  38:	00 00
  3a:	48                   	rex.W
  3b:	89                   	.byte 0x89
  3c:	84 24 a8             	test   %ah,(%rax,%rbp,4)