INFO: task syz-executor.0:4558 blocked for more than 143 seconds. Not tainted 5.15.178-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27672 pid: 4558 ppid: 4469 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 schedule_timeout+0xac/0x300 kernel/time/timer.c:1890 do_wait_for_common+0x2d9/0x480 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x48/0x60 kernel/sched/completion.c:138 flush_workqueue+0x737/0x1610 kernel/workqueue.c:2882 nbd_start_device_ioctl drivers/block/nbd.c:1365 [inline] __nbd_ioctl drivers/block/nbd.c:1427 [inline] nbd_ioctl+0xab8/0xe10 drivers/block/nbd.c:1467 blkdev_ioctl+0x333/0x6b0 block/ioctl.c:604 block_ioctl+0xb1/0xf0 block/fops.c:493 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f93d6d2fae9 RSP: 002b:00007f93d60900c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f93d6e4f050 RCX: 00007f93d6d2fae9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f93d6d7b47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f93d6e4f050 R15: 00007ffd803a9d58 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8cb1fce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3919: #0: ffff88802c79b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025c62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 2 locks held by kworker/u5:1/4175: #0: ffff88802163a938 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90002eefd20 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 1 lock held by syz-executor.0/8475: #0: ffff88802162ea08 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x146/0xe10 drivers/block/nbd.c:1460 1 lock held by syz-executor.0/8476: #0: ffff88802162ea08 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x146/0xe10 drivers/block/nbd.c:1460 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.178-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 144 Comm: kworker/u4:1 Not tainted 5.15.178-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:kasan_check_range+0x3/0x290 mm/kasan/generic.c:188 Code: 48 89 c7 e8 0f 84 75 08 31 c0 c3 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 cc cc cc cc cc cc cc cc cc cc cc cc 55 41 57 <41> 56 53 b0 01 48 85 f6 0f 84 9a 01 00 00 48 89 fd 48 01 f5 0f 82 RSP: 0018:ffffc9000171f988 EFLAGS: 00000046 RAX: 000000000000001d RBX: 000000000000077e RCX: ffffffff8162e2ff RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff9098c1e8 RBP: fdf3d8d65b8a314e R08: dffffc0000000000 R09: fffffbfff2131821 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000002 R13: ffff88801c48a8a8 R14: ffff88801c489dc0 R15: ffff88801c48a920 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f118da160c0 CR3: 0000000025dbf000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] hlock_class kernel/locking/lockdep.c:197 [inline] __lock_acquire+0xfaf/0x1ff0 kernel/locking/lockdep.c:5008 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0xc1/0x5b0 net/batman-adv/network-coding.c:723 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287