INFO: task syz-executor.0:14583 blocked for more than 143 seconds. Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27552 pid:14583 tgid:14581 ppid:9249 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5c70 kernel/sched/core.c:6736 __schedule_loop kernel/sched/core.c:6813 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6828 schedule_timeout+0x258/0x2a0 kernel/time/timer.c:2548 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x3de/0x5f0 kernel/sched/completion.c:116 __flush_workqueue+0x39e/0x1200 kernel/workqueue.c:3994 nbd_start_device_ioctl drivers/block/nbd.c:1463 [inline] __nbd_ioctl drivers/block/nbd.c:1524 [inline] nbd_ioctl+0x308/0xfd0 drivers/block/nbd.c:1564 blkdev_ioctl+0x2f7/0x770 block/ioctl.c:640 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7fa68e67dda9 RSP: 002b:00007fa68f4af0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa68e7abf80 RCX: 00007fa68e67dda9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007fa68e6ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fa68e7abf80 R15: 00007ffdd141feb8 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614 2 locks held by kworker/u9:0/52: #0: ffff888020393948 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work+0x1296/0x1a60 kernel/workqueue.c:3229 #1: ffffc90000bc7d80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x906/0x1a60 kernel/workqueue.c:3230 2 locks held by getty/4816: #0: ffff88802abe70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015f02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2201 2 locks held by kworker/u9:2/5100: #0: ffff888020847948 ((wq_completion)nbd3-recv){+.+.}-{0:0}, at: process_one_work+0x1296/0x1a60 kernel/workqueue.c:3229 #1: ffffc9000381fd80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x906/0x1a60 kernel/workqueue.c:3230 2 locks held by kworker/u9:3/5103: #0: ffff888020841948 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: process_one_work+0x1296/0x1a60 kernel/workqueue.c:3229 #1: ffffc9000385fd80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x906/0x1a60 kernel/workqueue.c:3230 2 locks held by kworker/u9:5/5106: #0: ffff888020375948 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x1296/0x1a60 kernel/workqueue.c:3229 #1: ffffc9000389fd80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x906/0x1a60 kernel/workqueue.c:3230 2 locks held by kworker/u9:8/5110: #0: ffff888020865948 ((wq_completion)nbd4-recv){+.+.}-{0:0}, at: process_one_work+0x1296/0x1a60 kernel/workqueue.c:3229 #1: ffffc900038ffd80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x906/0x1a60 kernel/workqueue.c:3230 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/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+0xf86/0x1210 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 1096 Comm: kworker/u8:6 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Workqueue: bat_events batadv_nc_worker RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:122 [inline] RIP: 0010:lock_acquire kernel/locking/lockdep.c:5730 [inline] RIP: 0010:lock_acquire+0x123/0x540 kernel/locking/lockdep.c:5719 Code: ab 50 33 0e 85 c9 0f 84 e3 00 00 00 65 8b 05 ac 38 97 7e 85 c0 0f 85 1d 01 00 00 65 48 8b 15 14 81 98 7e 48 8d ba d4 0a 00 00 <48> b8 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 0f b6 0c 01 48 RSP: 0018:ffffc90004887aa8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff92000910f57 RCX: 0000000000000001 RDX: ffff888022469e00 RSI: ffffffff8b6e8820 RDI: ffff88802246a8d4 RBP: 0000000000000001 R08: 0000000000000000 R09: fffffbfff1f3cdf2 R10: ffffffff8f9e6f97 R11: 0000000000000002 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8d7b08e0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f25c14d9053 CR3: 000000000d57a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] rcu_read_lock include/linux/rcupdate.h:750 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x16e/0x10f0 net/batman-adv/network-coding.c:719 process_one_work+0x9a9/0x1a60 kernel/workqueue.c:3254 process_scheduled_works kernel/workqueue.c:3335 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243