Dev nbd3: unable to read RDB block 0 INFO: task syz-executor.3:27116 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 EXT4-fs (loop4): mounting with "discard" option, but the device does not support discard nbd3: unable to read partition table EXT4-fs (loop4): mounted filesystem without journal. Opts: ,errors=continue "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. ldm_validate_partition_table(): Disk read failed. Dev nbd3: unable to read RDB block 0 syz-executor.3 D28304 27116 8124 0x00000004 nbd3: unable to read partition table Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 ldm_validate_partition_table(): Disk read failed. Dev nbd3: unable to read RDB block 0 nbd3: unable to read partition table schedule+0x8d/0x1b0 kernel/sched/core.c:3561 ldm_validate_partition_table(): Disk read failed. schedule_timeout+0x92d/0xfe0 kernel/time/timer.c:1794 Dev nbd3: unable to read RDB block 0 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common+0x29c/0x470 kernel/sched/completion.c:115 nbd3: unable to read partition table ldm_validate_partition_table(): Disk read failed. flush_workqueue+0x40b/0x13e0 kernel/workqueue.c:2713 Dev nbd3: unable to read RDB block 0 nbd3: unable to read partition table ldm_validate_partition_table(): Disk read failed. Dev nbd3: unable to read RDB block 0 nbd3: unable to read partition table ldm_validate_partition_table(): Disk read failed. nbd_start_device_ioctl drivers/block/nbd.c:1276 [inline] __nbd_ioctl drivers/block/nbd.c:1347 [inline] nbd_ioctl+0x75b/0xbe0 drivers/block/nbd.c:1387 Dev nbd3: unable to read RDB block 0 nbd3: unable to read partition table ldm_validate_partition_table(): Disk read failed. __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x5cb/0x1a80 block/ioctl.c:601 Dev nbd3: unable to read RDB block 0 block_ioctl+0xe9/0x130 fs/block_dev.c:1906 nbd3: unable to read partition table vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ldm_validate_partition_table(): Disk read failed. Dev nbd3: unable to read RDB block 0 nbd3: unable to read partition table ldm_validate_partition_table(): Disk read failed. ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 Dev nbd3: unable to read RDB block 0 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f38285b70f9 nbd3: unable to read partition table Code: Bad RIP value. ldm_validate_partition_table(): Disk read failed. RSP: 002b:00007f3826ae7168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 Dev nbd3: unable to read RDB block 0 RAX: ffffffffffffffda RBX: 00007f38286d7120 RCX: 00007f38285b70f9 nbd3: unable to read partition table RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 ldm_validate_partition_table(): Disk read failed. RBP: 00007f3828612ae9 R08: 0000000000000000 R09: 0000000000000000 Dev nbd3: unable to read RDB block 0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 nbd3: unable to read partition table R13: 00007ffd30582aef R14: 00007f3826ae7300 R15: 0000000000022000 ldm_validate_partition_table(): Disk read failed. Showing all locks held in the system: Dev nbd3: unable to read RDB block 0 1 lock held by khungtaskd/1570: #0: 00000000446442a6 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 nbd3: unable to read partition table 1 lock held by in:imklog/7796: ldm_validate_partition_table(): Disk read failed. #0: 00000000212f6dee (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 Dev nbd3: unable to read RDB block 0 2 locks held by syz-executor.4/8134: nbd3: unable to read partition table #0: 000000003012fe9d (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0xfc/0x870 fs/block_dev.c:1806 ldm_validate_partition_table(): Disk read failed. Dev nbd3: unable to read RDB block 0 #1: 00000000fad42682 (loop_ctl_mutex){+.+.}, at: __loop_clr_fd+0x88/0xe50 drivers/block/loop.c:1080 nbd3: unable to read partition table 2 locks held by kworker/u5:0/25686: #0: 00000000ba780d8c ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000002e3d6184 ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 2 locks held by syz-executor.0/4202: #0: 000000005e780aae (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1826 [inline] #0: 000000005e780aae (&rq->lock){-.-.}, at: __schedule+0x1f9/0x2040 kernel/sched/core.c:3455 #1: 00000000446442a6 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:428 [inline] #1: 00000000446442a6 (rcu_read_lock){....}, at: update_curr+0x2c3/0x870 kernel/sched/fair.c:857 1 lock held by syz-executor.3/4216: ldm_validate_partition_table(): Disk read failed. 1 lock held by syz-executor.3/4225: Dev nbd3: unable to read RDB block 0 #0: 00000000b6a74d0f (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x1d0/0x1480 fs/block_dev.c:1478 nbd3: unable to read partition table ============================================= ldm_validate_partition_table(): Disk read failed. Dev nbd3: unable to read RDB block 0 NMI backtrace for cpu 0 CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 nbd3: unable to read partition table Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4241 Comm: syz-executor.3 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 RIP: 0010:memory_is_nonzero mm/kasan/kasan.c:196 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/kasan.c:210 [inline] RIP: 0010:memory_is_poisoned mm/kasan/kasan.c:241 [inline] RIP: 0010:check_memory_region_inline mm/kasan/kasan.c:257 [inline] RIP: 0010:check_memory_region+0x91/0x170 mm/kasan/kasan.c:267 Code: 48 85 d2 4c 0f 49 da 49 c1 fb 03 45 85 db 0f 84 93 00 00 00 45 89 db 4a 8d 14 d8 eb 09 48 83 c0 08 48 39 d0 74 7b 48 83 38 00 <74> f1 48 8d 50 08 eb 09 48 83 c0 01 48 39 d0 74 0e 80 38 00 74 f2 RSP: 0018:ffff88805d677dc0 EFLAGS: 00000246 RAX: ffffed100a7a3248 RBX: ffffed100a7a3348 RCX: ffffffff83888121 RDX: ffffed100a7a3348 RSI: 0000000000000fe0 RDI: ffff888053d18a60 RBP: ffffed100a7a314c R08: 0000000000000001 R09: ffffed100a7a3347 R10: ffff888053d19a3f R11: 000000000000003f R12: 0000000000000004 R13: 00007f1002560b95 R14: ffff888053d18a60 R15: ffffffff8b270eb8 FS: 0000555556f0f400(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1002587263 CR3: 00000000960de000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: strncpy_from_user+0x91/0x350 lib/strncpy_from_user.c:116 getname_flags+0x113/0x590 fs/namei.c:151 getname fs/namei.c:211 [inline] user_path_create fs/namei.c:3696 [inline] do_symlinkat+0xce/0x2c0 fs/namei.c:4149 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f1002504a37 Code: 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0a 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff822fb638 EFLAGS: 00000202 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1002504a37 RDX: 00007f1002560b95 RSI: 00000000ffffff9c RDI: 00007fff822fb700 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007fff822fb4d0 R10: 00007fff822fb387 R11: 0000000000000202 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007fff822fb700