block nbd0: shutting down sockets INFO: task syz-executor340:7970 blocked for more than 140 seconds. Not tainted 4.14.288-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor340 D28464 7970 7969 0x80000006 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 blkdev_put+0x27/0x4c0 fs/block_dev.c:1826 blkdev_close+0x86/0xb0 fs/block_dev.c:1875 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xa44/0x2850 kernel/exit.c:868 do_group_exit+0x100/0x2e0 kernel/exit.c:965 get_signal+0x38d/0x1ca0 kernel/signal.c:2412 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:792 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f542c2cd3e9 RSP: 002b:00007ffefaa122d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffe00 RBX: 0000000000000000 RCX: 00007f542c2cd3e9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007ffefaa12478 R09: 00007ffefaa12478 R10: 00007ffefaa12478 R11: 0000000000000246 R12: 00007f542c28c700 R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000 INFO: task systemd-udevd:7973 blocked for more than 140 seconds. Not tainted 4.14.288-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd-udevd D27464 7973 4626 0x00000304 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 io_schedule+0xb5/0x120 kernel/sched/core.c:5035 wait_on_page_bit_common mm/filemap.c:1025 [inline] wait_on_page_bit+0x241/0x320 mm/filemap.c:1058 wait_on_page_locked include/linux/pagemap.h:527 [inline] wait_on_page_read mm/filemap.c:2680 [inline] do_read_cache_page+0x55f/0xc10 mm/filemap.c:2719 read_mapping_page include/linux/pagemap.h:398 [inline] read_dev_sector+0xbd/0x3c0 block/partition-generic.c:659 read_part_sector block/partitions/check.h:38 [inline] adfspart_check_ICS+0xf6/0xc00 block/partitions/acorn.c:366 check_partition+0x330/0x610 block/partitions/check.c:167 rescan_partitions+0x192/0x800 block/partition-generic.c:523 __blkdev_get+0xd7f/0x1090 fs/block_dev.c:1541 blkdev_get+0x88/0x890 fs/block_dev.c:1611 blkdev_open+0x1cc/0x250 fs/block_dev.c:1772 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0x628/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fe307706840 RSP: 002b:00007ffdd87bb578 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000055bf57b20880 RCX: 00007fe307706840 RDX: 000055bf56e52fe3 RSI: 00000000000a0800 RDI: 000055bf57b22210 RBP: 00007ffdd87bb6f0 R08: 000055bf56e52670 R09: 0000000000000010 R10: 000055bf56e52d0c R11: 0000000000000246 R12: 00007ffdd87bb640 R13: 000055bf57b23070 R14: 0000000000000003 R15: 000000000000000e Showing all locks held in the system: 1 lock held by khungtaskd/1534: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by syz-executor340/7970: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1826 1 lock held by systemd-udevd/7973: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1534 Comm: khungtaskd Not tainted 4.14.288-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff8723e38e