INFO: task syz-executor.2:7983 blocked for more than 140 seconds. Not tainted 4.14.262-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D24928 7983 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 fuse_lock_inode+0xb0/0xe0 fs/fuse/inode.c:365 fuse_lookup+0x74/0x390 fs/fuse/dir.c:367 lookup_slow+0x20a/0x400 fs/namei.c:1696 walk_component+0x6a1/0xbc0 fs/namei.c:1825 link_path_walk+0x823/0x10a0 fs/namei.c:2154 path_openat+0x15e/0x2970 fs/namei.c:3568 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: 0033:0x7f58ea40eb28 RSP: 002b:00007fff1c281cf0 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000708 RCX: 00007f58ea40eb28 RDX: 0000000000090800 RSI: 00007f58ea46828e RDI: 00000000ffffff9c RBP: 00007fff1c281dbc R08: 0000000000090800 R09: 00007f58ea46828e R10: 0000000000000000 R11: 0000000000000287 R12: 0000000000000000 R13: 000000000004ff1f R14: 000000000000000d R15: 00007fff1c281e20 INFO: task syz-executor.2:28506 blocked for more than 140 seconds. Not tainted 4.14.262-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D27680 28506 7983 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 request_wait_answer+0x30d/0x620 fs/fuse/dev.c:478 __fuse_request_send+0x108/0x1a0 fs/fuse/dev.c:498 fuse_request_send fs/fuse/dev.c:511 [inline] fuse_simple_request+0x2fa/0x790 fs/fuse/dev.c:569 fuse_lookup_name+0x228/0x550 fs/fuse/dir.c:330 fuse_lookup+0xcd/0x390 fs/fuse/dir.c:368 lookup_slow+0x20a/0x400 fs/namei.c:1696 walk_component+0x6a1/0xbc0 fs/namei.c:1825 link_path_walk+0x823/0x10a0 fs/namei.c:2154 path_openat+0x15e/0x2970 fs/namei.c:3568 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: 0033:0x7f58ea40efe9 RSP: 002b:00007f58e8d42168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f58ea522100 RCX: 00007f58ea40efe9 RDX: 0000000000000042 RSI: 0000000020002080 RDI: ffffffffffffff9c RBP: 00007f58ea46908d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff1c281aff R14: 00007f58e8d42300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1534: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by syz-executor.2/7983: #0: (&type->i_mutex_dir_key#8){++++}, at: [] inode_lock_shared include/linux/fs.h:729 [inline] #0: (&type->i_mutex_dir_key#8){++++}, at: [] lookup_slow+0x129/0x400 fs/namei.c:1674 #1: (&fi->mutex){+.+.}, at: [] fuse_lock_inode+0xb0/0xe0 fs/fuse/inode.c:365 2 locks held by syz-executor.2/28506: #0: (&type->i_mutex_dir_key#8){++++}, at: [] inode_lock_shared include/linux/fs.h:729 [inline] #0: (&type->i_mutex_dir_key#8){++++}, at: [] lookup_slow+0x129/0x400 fs/namei.c:1674 #1: (&fi->mutex){+.+.}, at: [] fuse_lock_inode+0xb0/0xe0 fs/fuse/inode.c:365 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1534 Comm: khungtaskd Not tainted 4.14.262-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 skipped: idling at pc 0xffffffff8723efbe