INFO: task syz-executor.0:5417 blocked for more than 143 seconds. Not tainted 6.12.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:25912 pid:5417 tgid:5416 ppid:5338 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ac0 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2591 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 __flush_workqueue+0x702/0x15f0 kernel/workqueue.c:3973 nbd_start_device_ioctl drivers/block/nbd.c:1478 [inline] __nbd_ioctl drivers/block/nbd.c:1539 [inline] nbd_ioctl+0xbd1/0xf40 drivers/block/nbd.c:1579 blkdev_ioctl+0x57d/0x6a0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x82/0x160 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f714027cae9 RSP: 002b:00007f7140fe80c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f714039bf80 RCX: 00007f714027cae9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f71402c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f714039bf80 R15: 00007fff3a18a178 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8df352a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8df352a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8df352a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 2 locks held by kworker/u9:1/4438: #0: ffff88801eeb4148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801eeb4148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc9000cb9fd20 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000cb9fd20 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 2 locks held by getty/4790: #0: ffff88814b61f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by syz-executor.0/9548: #0: ffff88801eeb0198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x13c/0xf40 drivers/block/nbd.c:1572 1 lock held by syz-executor.0/9549: #0: ffff88801eeb0198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x13c/0xf40 drivers/block/nbd.c:1572 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xfec/0x1030 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2853 Comm: kworker/u8:9 Not tainted 6.12.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: bat_events batadv_nc_worker RIP: 0010:lock_acquire+0x37/0x540 kernel/locking/lockdep.c:5793 Code: 55 41 54 53 48 83 e4 e0 48 81 ec 20 01 00 00 4c 89 4c 24 28 4c 89 44 24 38 48 89 4c 24 30 89 54 24 1c 41 89 f6 48 89 7c 24 20 <65> 48 8b 04 25 28 00 00 00 48 89 84 24 00 01 00 00 49 bd 00 00 00 RSP: 0018:ffffc90009267a00 EFLAGS: 00000286 RAX: ffffffff8b0d91fb RBX: ffff88802914c580 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8df352a0 RBP: ffffc90009267b60 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1ed53ee R12: ffff888021d48c00 R13: 00000000000003e3 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1897ec56be CR3: 000000007a32e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xec/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1840 kernel/workqueue.c:3310 worker_thread+0xa2b/0xf70 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244