syzbot

INFO: task syz-executor.0:28692 blocked for more than 143 seconds.
      Not tainted 6.6.0-rc2-syzkaller-00018-g2cf0f7156238 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:27808 pid:28692 ppid:5077   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0xee1/0x5a10 kernel/sched/core.c:6695
 schedule+0xe7/0x1b0 kernel/sched/core.c:6771
 schedule_timeout+0x278/0x2c0 kernel/time/timer.c:2143
 ___down_common kernel/locking/semaphore.c:225 [inline]
 __down_common+0x327/0x6c0 kernel/locking/semaphore.c:246
 down+0x74/0xa0 kernel/locking/semaphore.c:63
 console_lock+0x96/0x150 kernel/printk/printk.c:2652
 vt_ioctl+0x144d/0x2ff0 drivers/tty/vt/vt_ioctl.c:815
 tty_ioctl+0x663/0x1580 drivers/tty/tty_io.c:2776
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl fs/ioctl.c:857 [inline]
 __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa56827cae9
RSP: 002b:00007fa568fea0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fa56839bf80 RCX: 00007fa56827cae9
RDX: 0000000020000280 RSI: 0000000000005603 RDI: 0000000000000005
RBP: 00007fa5682c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fa56839bf80 R15: 00007fa5684bfa48
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8cbab2e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:303 [inline]
 #0: ffffffff8cbab2e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:749 [inline]
 #0: ffffffff8cbab2e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613
2 locks held by getty/4797:
 #0: ffff88802602c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002efe2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc5/0x1480 drivers/tty/n_tty.c:2206
2 locks held by kworker/0:2/23325:
 #0: ffff888012c70d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605
 #1: ffffc900035d7d80 (console_work){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606
2 locks held by kworker/u4:15/7173:
2 locks held by kworker/u4:29/8905:
2 locks held by syz-executor.0/28717:
3 locks held by syz-executor.0/28882:

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

NMI backtrace for cpu 0
CPU: 0 PID: 30 Comm: khungtaskd Not tainted 6.6.0-rc2-syzkaller-00018-g2cf0f7156238 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x277/0x380 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x299/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf87/0x1210 kernel/hung_task.c:379
 kthread+0x33c/0x440 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8905 Comm: kworker/u4:29 Not tainted 6.6.0-rc2-syzkaller-00018-g2cf0f7156238 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Workqueue: bat_events batadv_dat_purge
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:67 [inline]
RIP: 0010:lockdep_hardirqs_on+0x51/0x100 kernel/locking/lockdep.c:4408
Code: 00 00 f0 00 48 89 fd 75 41 65 8b 05 09 4d c4 75 85 c0 75 69 65 8b 05 1a 4a c4 75 85 c0 75 5e 8b 35 14 99 ef 07 85 f6 75 21 9c <58> f6 c4 02 75 7a 8b 15 03 99 ef 07 85 d2 75 10 48 8b 83 b8 0a 00
RSP: 0018:ffffc9000a227c40 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88802ed7d940 RCX: 1ffffffff234ae60
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff814fcb64
RBP: ffffffff814fcb64 R08: 0000000000000001 R09: fffffbfff233ddf0
R10: ffffffff919eef87 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff88802ed25b90 R14: ffffffff8a057c20 R15: 0000000000000372
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f31c4f77978 CR3: 000000000c976000 CR4: 00000000003506e0
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __local_bh_enable_ip+0xa4/0x120 kernel/softirq.c:386
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 __batadv_dat_purge.part.0+0x27d/0x3b0 net/batman-adv/distributed-arp-table.c:186
 __batadv_dat_purge net/batman-adv/distributed-arp-table.c:167 [inline]
 batadv_dat_purge+0x4b/0xa0 net/batman-adv/distributed-arp-table.c:205
 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784
 kthread+0x33c/0x440 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
 </TASK>