INFO: task syz-executor4:6582 blocked for more than 140 seconds. Not tainted 4.18.0-rc7+ #78 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D24056 6582 4408 0x20020004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603 __mutex_lock_common kernel/locking/mutex.c:834 [inline] __mutex_lock+0xede/0x1820 kernel/locking/mutex.c:894 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909 fuse_lock_inode+0xaf/0xe0 fs/fuse/inode.c:363 fuse_lookup+0x8f/0x4c0 fs/fuse/dir.c:359 __lookup_slow+0x2b5/0x540 fs/namei.c:1630 lookup_slow+0x57/0x80 fs/namei.c:1647 walk_component+0x94a/0x2630 fs/namei.c:1769 lookup_last fs/namei.c:2237 [inline] path_lookupat.isra.45+0x202/0xbf0 fs/namei.c:2287 filename_lookup+0x264/0x510 fs/namei.c:2321 kern_path+0x33/0x40 fs/namei.c:2410 bpf_obj_do_get kernel/bpf/inode.c:455 [inline] bpf_obj_get_user+0x174/0x610 kernel/bpf/inode.c:495 bpf_obj_get+0xbe/0x100 kernel/bpf/syscall.c:1409 __do_sys_bpf kernel/bpf/syscall.c:2313 [inline] __se_sys_bpf kernel/bpf/syscall.c:2269 [inline] __ia32_sys_bpf+0x396/0x510 kernel/bpf/syscall.c:2269 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f78cb9 Code: Bad RIP value. RSP: 002b:00000000f5f320cc EFLAGS: 00000296 ORIG_RAX: 0000000000000165 RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00000000200002c0 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor4:6585 blocked for more than 140 seconds. Not tainted 4.18.0-rc7+ #78 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D23480 6585 4408 0x20020004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 request_wait_answer+0x4c8/0x920 fs/fuse/dev.c:463 __fuse_request_send+0x12a/0x1d0 fs/fuse/dev.c:483 fuse_request_send+0x62/0xa0 fs/fuse/dev.c:496 fuse_simple_request+0x33d/0x730 fs/fuse/dev.c:554 fuse_lookup_name+0x3ee/0x830 fs/fuse/dir.c:323 fuse_lookup+0xf9/0x4c0 fs/fuse/dir.c:360 __lookup_slow+0x2b5/0x540 fs/namei.c:1630 lookup_slow+0x57/0x80 fs/namei.c:1647 mountpoint_last fs/namei.c:2641 [inline] path_mountpoint+0x6ca/0x21e0 fs/namei.c:2672 filename_mountpoint+0x242/0x460 fs/namei.c:2698 user_path_mountpoint_at+0x37/0x40 fs/namei.c:2728 ksys_umount+0x1c9/0x12e0 fs/namespace.c:1700 __do_sys_umount fs/namespace.c:1726 [inline] __se_sys_umount fs/namespace.c:1724 [inline] __ia32_sys_umount+0x53/0x80 fs/namespace.c:1724 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f78cb9 Code: Bad RIP value. RSP: 002b:00000000f5f110cc EFLAGS: 00000296 ORIG_RAX: 0000000000000034 RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/773: #0: 00000000d741169e (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 1 lock held by rsyslogd/4268: 2 locks held by getty/4358: #0: 00000000fecfe55c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000002baca2bf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4359: #0: 00000000fbc623ad (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000005dbe9845 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4360: #0: 000000007be283c5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000000118cf85 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4361: #0: 00000000af15a228 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000cecda9f9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4362: #0: 00000000388b035f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000005ac1217c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4363: #0: 000000004beabe48 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000fb83b9cb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4364: #0: 00000000948d5434 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000000ac937db (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor4/6582: #0: 000000003053349f (&type->i_mutex_dir_key#5){.+.+}, at: inode_lock_shared include/linux/fs.h:725 [inline] #0: 000000003053349f (&type->i_mutex_dir_key#5){.+.+}, at: lookup_slow+0x49/0x80 fs/namei.c:1646 #1: 00000000478cc5de (&fi->mutex){+.+.}, at: fuse_lock_inode+0xaf/0xe0 fs/fuse/inode.c:363 2 locks held by syz-executor4/6585: #0: 000000003053349f (&type->i_mutex_dir_key#5){.+.+}, at: inode_lock_shared include/linux/fs.h:725 [inline] #0: 000000003053349f (&type->i_mutex_dir_key#5){.+.+}, at: lookup_slow+0x49/0x80 fs/namei.c:1646 #1: 00000000478cc5de (&fi->mutex){+.+.}, at: fuse_lock_inode+0xaf/0xe0 fs/fuse/inode.c:363 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 773 Comm: khungtaskd Not tainted 4.18.0-rc7+ #78 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 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:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x9c4/0xf80 kernel/hung_task.c:252 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54