XFS (loop3): Invalid superblock magic number INFO: task syz-executor.4:1606 blocked for more than 140 seconds. Not tainted 4.14.212-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28968 1606 7996 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x1e6/0x350 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:66 [inline] down_read+0x44/0x80 kernel/locking/rwsem.c:26 __get_super.part.0+0x271/0x390 fs/super.c:678 __get_super include/linux/spinlock.h:317 [inline] get_super+0x2b/0x50 fs/super.c:707 fsync_bdev+0x14/0xc0 fs/block_dev.c:495 invalidate_partition+0x74/0xb0 block/genhd.c:1506 drop_partitions.isra.0+0x83/0x150 block/partition-generic.c:442 rescan_partitions+0xa9/0x800 block/partition-generic.c:515 __blkdev_reread_part+0x140/0x1d0 block/ioctl.c:173 blkdev_reread_part+0x23/0x40 block/ioctl.c:193 loop_reread_partitions drivers/block/loop.c:624 [inline] loop_set_status+0xeeb/0x12b0 drivers/block/loop.c:1193 loop_set_status64+0x92/0xe0 drivers/block/loop.c:1311 lo_ioctl+0x587/0x1cd0 drivers/block/loop.c:1441 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x540/0x1830 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1893 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45dfb7 RSP: 002b:00007f39799fe9e8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045dfb7 RDX: 00007f39799feab0 RSI: 0000000000004c04 RDI: 0000000000000004 RBP: 000000000119c068 R08: 00007f39799fea18 R09: 0000000000000000 R10: 00007f39799fea1c R11: 0000000000000202 R12: 000000000119c034 R13: 00007ffde7247abf R14: 00007f39799ff9c0 R15: 000000000119c034 Showing all locks held in the system: 1 lock held by khungtaskd/1532: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 3 locks held by syz-executor.4/1606: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1cd0 drivers/block/loop.c:1414 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 #2: (&type->s_umount_key#91){.+.+}, at: [] __get_super.part.0+0x271/0x390 fs/super.c:678 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1532 Comm: khungtaskd Not tainted 4.14.212-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x17f 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 CPU: 1 PID: 162 Comm: kworker/u4:3 Not tainted 4.14.212-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff8880b5110600 task.stack: ffff8880b52e8000 RIP: 0010:in_lock_functions+0xd/0x20 kernel/locking/spinlock.c:398 RSP: 0018:ffff8880b52efc30 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff87209b13 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: 0000000000000201 RDI: ffffffff87209b13 RBP: ffff8880b5110600 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8708449e R13: ffffffff87085fd0 R14: ffff88805fefa5f8 R15: ffff88805fee67c0 FS: 0000000000000000(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faff0398008 CR3: 00000000a59cc000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: get_lock_parent_ip include/linux/ftrace.h:730 [inline] __local_bh_disable_ip+0x108/0x190 kernel/softirq.c:134 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:134 [inline] _raw_spin_lock_bh+0x13/0x40 kernel/locking/spinlock.c:176 spin_lock_bh include/linux/spinlock.h:322 [inline] batadv_nc_purge_paths+0xce/0x300 net/batman-adv/network-coding.c:450 batadv_nc_worker+0x660/0xc50 net/batman-adv/network-coding.c:729 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 00 08 38 8b e8 75 c1 3d 00 eb 88 0f 1f 00 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 31 c0 48 81 ff 38 9a 20 87 72 0c 31 c0 <48> 81 ff 1f a8 20 87 0f 92 c0 c3 90 90 90 90 90 90 90 90 41 57