INFO: task syz-executor.0:12810 blocked for more than 140 seconds. Not tainted 4.14.230-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29184 12810 7985 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 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 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: 0033:0x466217 RSP: 002b:00007fbda716bef8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fbda716bf40 RCX: 0000000000466217 RDX: 00007fbda716c050 RSI: 0000000000004c04 RDI: 0000000000000006 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007fbda716c050 R13: 00007ffe7ffd5b9f R14: 00007fbda716c300 R15: 0000000000022000 INFO: task syz-executor.3:12802 blocked for more than 140 seconds. Not tainted 4.14.230-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28536 12802 7989 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 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 loop_control_ioctl+0x181/0x3f0 drivers/block/loop.c:2007 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: 0033:0x466459 RSP: 002b:00007f4ba22ec188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffec7b9aeef R14: 00007f4ba22ec300 R15: 0000000000022000 INFO: task systemd-udevd:12807 blocked for more than 140 seconds. Not tainted 4.14.230-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd-udevd D28416 12807 4628 0x00000100 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 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1634 __blkdev_get+0xa8c/0x1090 fs/block_dev.c:1537 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: 0033:0x7f6ad319d840 RSP: 002b:00007ffe91c58268 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000055b293970c20 RCX: 00007f6ad319d840 RDX: 000055b291dbafe3 RSI: 0000000000080000 RDI: 000055b293972e90 RBP: 0000000000000001 R08: 000055b291dba670 R09: 0000000000000110 R10: 00000000000002fe R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 000055b293970e20 R15: 00000000ffffffff INFO: task syz-executor.1:12817 blocked for more than 140 seconds. Not tainted 4.14.230-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D30016 12817 7986 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 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 loop_control_ioctl+0x67/0x3f0 drivers/block/loop.c:1993 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: 0033:0x466459 RSP: 002b:00007f3a1ef28188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 000000000000000b RSI: 0000000000004c81 RDI: 0000000000000004 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffdc622a2df R14: 00007f3a1ef28300 R15: 0000000000022000 INFO: task syz-executor.1:12820 blocked for more than 140 seconds. Not tainted 4.14.230-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D30528 12820 7986 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 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 loop_control_ioctl+0x67/0x3f0 drivers/block/loop.c:1993 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: 0033:0x466459 RSP: 002b:00007f3a1ef07188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000466459 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000004 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008 R13: 00007ffdc622a2df R14: 00007f3a1ef07300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1533: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by syz-executor.0/12810: #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 locks held by syz-executor.3/12802: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x67/0x3f0 drivers/block/loop.c:1993 #1: (&lo->lo_ctl_mutex){+.+.}, at: [] loop_control_ioctl+0x181/0x3f0 drivers/block/loop.c:2007 2 locks held by systemd-udevd/12807: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1634 1 lock held by syz-executor.1/12817: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x67/0x3f0 drivers/block/loop.c:1993 1 lock held by syz-executor.1/12820: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x67/0x3f0 drivers/block/loop.c:1993 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.230-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+0x1b2/0x281 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 16863 Comm: kworker/u4:7 Not tainted 4.14.230-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff88807c5b86c0 task.stack: ffff88807ebc0000 RIP: 0010:__sanitizer_cov_trace_pc+0x9/0x50 kernel/kcov.c:65 RSP: 0018:ffff88807ebc7c10 EFLAGS: 00000202 RAX: ffff88807c5b86c0 RBX: ffff8880b2dc2bc0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff87cce9c0 RDI: ffffffff87ccea00 RBP: ffffffff87ccea00 R08: 0000000000000000 R09: 0000000000020012 R10: ffff88807c5b8f98 R11: ffff88807c5b86c0 R12: 0000000000000000 R13: ffffffff87cce9c0 R14: ffff8880a9a6d200 R15: 000000000000000a FS: 0000000000000000(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3677fbf028 CR3: 00000000b3456000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_preemption_disabled+0x30/0x240 lib/smp_processor_id.c:26 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:360 [inline] rcu_is_watching+0x11/0xb0 kernel/rcu/tree.c:1130 rcu_read_unlock include/linux/rcupdate.h:681 [inline] batadv_nc_process_nc_paths.part.0+0x2b1/0x350 net/batman-adv/network-coding.c:707 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:687 [inline] batadv_nc_worker+0x8b8/0xc50 net/batman-adv/network-coding.c:735 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 e9 9f fe ff ff 4c 89 e7 e8 a4 a4 29 00 e9 2c fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 80 df 01 00 <48> 85 c0 74 1a 65 8b 15 8b b9 ac 7e 81 e2 00 01 1f 00 75 0b 8b