loop5: unable to read partition table loop5: partition table beyond EOD, truncated loop_reread_partitions: partition scan of loop5 () failed (rc=-5) Dev loop0: unable to read RDB block 1 loop0: unable to read partition table INFO: task kworker/u4:2:25 blocked for more than 140 seconds. Not tainted 4.14.171-syzkaller #0 loop0: partition table beyond EOD, truncated "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. loop_reread_partitions: partition scan of loop0 () failed (rc=-5) kworker/u4:2 D26176 25 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3384 schedule+0x92/0x1c0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 Dev loop4: unable to read RDB block 1 loop4: unable to read partition table loop4: partition table beyond EOD, truncated loop_reread_partitions: partition scan of loop4 () failed (rc=-5) mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 cleanup_net+0x11c/0x870 net/core/net_namespace.c:450 process_one_work+0x863/0x1600 kernel/workqueue.c:2114 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Showing all locks held in the system: 3 locks held by kworker/u4:2/25: #0: ("%s""netns"){+.+.}, at: [] work_static include/linux/workqueue.h:199 [inline] #0: ("%s""netns"){+.+.}, at: [] set_work_data kernel/workqueue.c:619 [inline] #0: ("%s""netns"){+.+.}, at: [] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ("%s""netns"){+.+.}, at: [] process_one_work+0x76e/0x1600 kernel/workqueue.c:2085 #1: (net_cleanup_work){+.+.}, at: [] process_one_work+0x7ab/0x1600 kernel/workqueue.c:2089 #2: (net_mutex){+.+.}, at: [] cleanup_net+0x11c/0x870 net/core/net_namespace.c:450 1 lock held by khungtaskd/1046: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4544 4 locks held by udevd/3717: #0: (sb_writers#8){.+.+}, at: [] file_start_write include/linux/fs.h:2707 [inline] #0: (sb_writers#8){.+.+}, at: [] vfs_write+0x3af/0x500 fs/read_write.c:543 #1: (&of->mutex){+.+.}, at: [] kernfs_fop_write+0x1dd/0x450 fs/kernfs/file.c:307 #2: (kn->count#7){++++}, at: [] kernfs_fop_write+0x200/0x450 fs/kernfs/file.c:308 #3: (uevent_sock_mutex){+.+.}, at: [] kobject_uevent_env+0x5b3/0xc80 lib/kobject_uevent.c:459 2 locks held by getty/7442: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7443: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7444: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7445: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7446: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7447: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7448: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.2/18193: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 #1: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 #2: (uevent_sock_mutex){+.+.}, at: [] kobject_uevent_env+0x5b3/0xc80 lib/kobject_uevent.c:459 1 lock held by syz-executor.2/18349: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/18389: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18398: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/18408: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18422: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18438: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18457: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18475: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18493: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18504: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18524: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18596: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18613: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18628: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18640: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18660: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18679: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.2/18695: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/18941: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/18959: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/18980: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19030: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19054: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19088: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19104: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19122: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19213: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19239: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19257: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19284: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19316: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19417: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19433: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19454: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/19464: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 2 locks held by syz-executor.4/29725: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8f/0x1cd0 drivers/block/loop.c:1414 #1: (uevent_sock_mutex){+.+.}, at: [] kobject_uevent_env+0x5b3/0xc80 lib/kobject_uevent.c:459 2 locks held by syz-executor.0/29749: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8f/0x1cd0 drivers/block/loop.c:1414 #1: (uevent_sock_mutex){+.+.}, at: [] kobject_uevent_env+0x5b3/0xc80 lib/kobject_uevent.c:459 1 lock held by blkid/29747: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8f/0x1cd0 drivers/block/loop.c:1414 1 lock held by syz-executor.2/29752: #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock_nested fs/pipe.c:67 [inline] #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock fs/pipe.c:75 [inline] #0: (&pipe->mutex/1){+.+.}, at: [] pipe_wait+0x181/0x1a0 fs/pipe.c:123 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1046 Comm: khungtaskd Not tainted 4.14.171-syzkaller #0 Dev loop5: unable to read RDB block 1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: loop5: unable to read partition table __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x142/0x197 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x141/0x189 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:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e7/0xb90 kernel/hung_task.c:274 kthread+0x319/0x430 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: 29758 Comm: syz-executor.2 Not tainted 4.14.171-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88820c7c83c0 task.stack: ffff888203088000 RIP: 0010:page_fault+0x0/0x50 arch/x86/entry/entry_64.S:1121 RSP: 0018:ffff88820308fb00 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 0000000000001000 RCX: 0000000000000500 RDX: 0000000000001000 RSI: ffff888023168b00 RDI: 00000000200bc000 RBP: ffff88820308fb60 R08: ffffed100462d200 R09: 0000000000000000 R10: ffffed100462d1ff R11: ffff888023168fff R12: 00000000200bb500 R13: ffff888023168000 R14: 00007ffffffff000 R15: 00000000200bc500 FS: 00007f4ec17d1700(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200bc000 CR3: 000000003ec98000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: copy_page_to_iter_iovec lib/iov_iter.c:206 [inline] copy_page_to_iter+0x31b/0xc40 lib/iov_iter.c:723 pipe_to_user+0xb0/0x160 fs/splice.c:1237 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x348/0x780 fs/splice.c:626 vmsplice_to_user+0x197/0x1c0 fs/splice.c:1272 SYSC_vmsplice fs/splice.c:1353 [inline] SyS_vmsplice+0x131/0x160 fs/splice.c:1334 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c449 RSP: 002b:00007f4ec17d0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000116 RAX: ffffffffffffffda RBX: 00007f4ec17d16d4 RCX: 000000000045c449 RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000006 RBP: 000000000076c060 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000c45 R14: 00000000004ce24e R15: 000000000076c06c Code: e9 96 02 00 00 e8 b1 01 00 00 48 89 e7 48 8b 74 24 78 48 c7 44 24 78 ff ff ff ff e8 8b 5b a0 fa e9 76 02 00 00 66 0f 1f 44 00 00 <0f> 1f 00 f6 44 24 10 03 75 20 e8 81 01 00 00 48 89 e7 48 8b 74 loop5: partition table beyond EOD,