EXT4-fs error (device loop0): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs (loop3): mount failed EXT4-fs (loop0): get root inode failed EXT4-fs (loop0): mount failed EXT4-fs error (device loop4): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated INFO: task syz-executor.2:5844 blocked for more than 140 seconds. Not tainted 4.18.0-syzkaller #0 EXT4-fs (loop4): get root inode failed "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. EXT4-fs (loop4): mount failed syz-executor.2 D27480 5844 8572 0x00080004 EXT4-fs error (device loop1): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs (loop1): get root inode failed Call Trace: EXT4-fs (loop1): mount failed context_switch kernel/sched/core.c:2853 [inline] __schedule+0x80c/0x1fc0 kernel/sched/core.c:3501 schedule+0x7f/0x1b0 kernel/sched/core.c:3545 EXT4-fs error (device loop0): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated schedule_timeout+0x70e/0xd20 kernel/time/timer.c:1777 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common+0x3fb/0x5d0 kernel/sched/completion.c:115 EXT4-fs (loop0): get root inode failed EXT4-fs (loop0): mount failed wait_for_completion+0x18/0x20 kernel/sched/completion.c:136 kthread_stop+0xc9/0x550 kernel/kthread.c:548 ext4_fill_super+0x71af/0xaf00 fs/ext4/super.c:4497 EXT4-fs error (device loop5): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs error (device loop3): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs error (device loop4): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs (loop3): get root inode failed EXT4-fs (loop5): get root inode failed EXT4-fs (loop4): get root inode failed EXT4-fs (loop5): mount failed EXT4-fs (loop3): mount failed EXT4-fs (loop4): mount failed EXT4-fs error (device loop1): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs (loop1): get root inode failed mount_bdev+0x26f/0x330 fs/super.c:1174 EXT4-fs (loop1): mount failed ext4_mount+0x10/0x20 fs/ext4/super.c:5839 mount_fs+0x7f/0x2a9 fs/super.c:1277 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2542 [inline] do_mount+0x376/0x2710 fs/namespace.c:2872 EXT4-fs error (device loop0): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs (loop0): get root inode failed EXT4-fs (loop0): mount failed ksys_mount+0xb1/0xd0 fs/namespace.c:3088 __do_sys_mount fs/namespace.c:3102 [inline] __se_sys_mount fs/namespace.c:3099 [inline] __x64_sys_mount+0xb9/0x150 fs/namespace.c:3099 do_syscall_64+0xda/0x540 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f49519f3f6a Code: Bad RIP value. RSP: 002b:00007f4951146fa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007f49519f3f6a EXT4-fs error (device loop4): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f4951147000 EXT4-fs (loop4): get root inode failed RBP: 00007f4951147040 R08: 00007f4951147040 R09: 0000000020000000 EXT4-fs (loop4): mount failed R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000 R13: 0000000020000100 R14: 00007f4951147000 R15: 0000000020000340 Showing all locks held in the system: EXT4-fs error (device loop3): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs error (device loop5): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs error (device loop1): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs (loop5): get root inode failed EXT4-fs (loop3): get root inode failed 1 lock held by khungtaskd/1509: EXT4-fs (loop3): mount failed #0: 00000000b6b11035 (rcu_read_lock){....}, at: debug_show_all_locks+0x5b/0x27a kernel/locking/lockdep.c:4461 EXT4-fs (loop1): get root inode failed 1 lock held by in:imklog/7886: EXT4-fs error (device loop0): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs (loop5): mount failed #0: 0000000000cdfad3 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xa7/0xd0 fs/file.c:766 EXT4-fs (loop1): mount failed EXT4-fs (loop0): get root inode failed EXT4-fs (loop0): mount failed 1 lock held by syz-executor.2/5844: #0: 0000000064b86184 (&type->s_umount_key#25/1){+.+.}, at: alloc_super fs/super.c:223 [inline] #0: 0000000064b86184 (&type->s_umount_key#25/1){+.+.}, at: sget_userns+0x1a1/0xb60 fs/super.c:516 EXT4-fs error (device loop4): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs (loop4): get root inode failed 1 lock held by systemd-udevd/6155: EXT4-fs (loop4): mount failed 1 lock held by syz-executor241/11351: #0: 00000000aaada9eb (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x86/0x1a80 drivers/block/loop.c:1405 1 lock held by syz-executor241/11370: #0: 000000002f6611bd (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x86/0x1a80 drivers/block/loop.c:1405 1 lock held by syz-executor241/11381: EXT4-fs error (device loop3): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated #0: 00000000128d37e7 (&bdev->bd_mutex){+.+.}, at: blkdev_put+0x25/0x470 fs/block_dev.c:1814 EXT4-fs (loop3): get root inode failed 4 locks held by syz-executor241/11408: EXT4-fs (loop3): mount failed EXT4-fs error (device loop4): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs (loop4): get root inode failed EXT4-fs (loop4): mount failed #0: EXT4-fs error (device loop0): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated 00000000b2639435 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1812 [inline] 00000000b2639435 (&rq->lock){-.-.}, at: __schedule+0x1f6/0x1fc0 kernel/sched/core.c:3439 EXT4-fs (loop0): get root inode failed #1: 00000000b6b11035 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:413 [inline] #1: 00000000b6b11035 (rcu_read_lock){....}, at: update_curr+0x2d1/0x8b0 kernel/sched/fair.c:831 EXT4-fs error (device loop5): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated #2: EXT4-fs error (device loop1): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs (loop0): mount failed 000000003e00b823 EXT4-fs (loop5): get root inode failed ( EXT4-fs (loop5): mount failed &sig->wait_chldexit){....}, at: __wake_up_common_lock+0xba/0x180 kernel/sched/wait.c:118 EXT4-fs (loop1): get root inode failed EXT4-fs (loop1): mount failed #3: 0000000054d56fd5 (&(&sig->stats_lock)->seqcount){....}, at: release_task kernel/exit.c:184 [inline] #3: 0000000054d56fd5 (&(&sig->stats_lock)->seqcount){....}, at: exit_notify kernel/exit.c:735 [inline] #3: 0000000054d56fd5 (&(&sig->stats_lock)->seqcount){....}, at: do_exit+0x173a/0x2aa0 kernel/exit.c:885 EXT4-fs error (device loop3): ext4_iget:4777: inode #2: comm syz-executor241: root inode unallocated EXT4-fs (loop3): get root inode failed 2 locks held by syz-executor241/11416: EXT4-fs (loop3): mount failed 1 lock held by syz-executor241/11425: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1509 Comm: khungtaskd Not tainted 4.18.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x15a/0x20d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.0+0x13/0xb6 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0xf6/0x11a lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x512/0x940 kernel/hung_task.c:252 kthread+0x316/0x3d0 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54