INFO: task syz-executor7:13936 blocked for more than 140 seconds. Not tainted 4.18.0-rc7+ #177 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D23800 13936 4342 0x00000004 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 __rwsem_down_write_failed_common+0x95d/0x1630 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write_nested+0xae/0x130 kernel/locking/rwsem.c:194 inode_lock_nested include/linux/fs.h:750 [inline] do_unlinkat+0x3d8/0xa30 fs/namei.c:4059 __do_sys_unlink fs/namei.c:4120 [inline] __se_sys_unlink fs/namei.c:4118 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4118 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456b29 Code: 42 08 84 00 48 83 c0 58 48 89 04 24 e8 00 8b fb ff 48 8b 6c 24 08 48 83 c4 10 c3 e8 91 33 00 00 eb bf cc cc cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 2b RSP: 002b:00007f3042e38c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007f3042e396d4 RCX: 0000000000456b29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000480 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d6110 R14: 00000000004c71c7 R15: 0000000000000000 INFO: task syz-executor7:13940 blocked for more than 140 seconds. Not tainted 4.18.0-rc7+ #177 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D24264 13940 4342 0x00000004 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 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] __x64_sys_bpf+0x396/0x510 kernel/bpf/syscall.c:2269 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456b29 Code: 42 08 84 00 48 83 c0 58 48 89 04 24 e8 00 8b fb ff 48 8b 6c 24 08 48 83 c4 10 c3 e8 91 33 00 00 eb bf cc cc cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 2b RSP: 002b:00007f3042e17c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f3042e186d4 RCX: 0000000000456b29 RDX: 0000000000000010 RSI: 00000000200002c0 RDI: 0000000000000007 RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004ca968 R14: 00000000004c28f0 R15: 0000000000000001 Showing all locks held in the system: 1 lock held by khungtaskd/773: #0: 0000000008827bcc (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 1 lock held by rsyslogd/4203: 2 locks held by getty/4293: #0: 00000000b9350295 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000047c31212 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4294: #0: 00000000b2add428 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000021dd402a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4295: #0: 00000000362a91a4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000178f84cd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4296: #0: 00000000b4fe25ad (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000006fa7c68b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4297: #0: 00000000ec3f7893 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000002fc79953 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4298: #0: 000000006055be29 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000009533741a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4299: #0: 00000000ab5b52be (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000c8172564 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor7/13936: #0: 00000000048dd94a (sb_writers#16){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000048dd94a (sb_writers#16){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000e34cc50b (&type->i_mutex_dir_key#5/1){+.+.}, at: inode_lock_nested include/linux/fs.h:750 [inline] #1: 00000000e34cc50b (&type->i_mutex_dir_key#5/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4059 2 locks held by syz-executor7/13940: #0: 00000000e34cc50b (&type->i_mutex_dir_key#5){++++}, at: inode_lock_shared include/linux/fs.h:725 [inline] #0: 00000000e34cc50b (&type->i_mutex_dir_key#5){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1646 #1: 00000000f91a0a51 (&fi->mutex){+.+.}, at: fuse_lock_inode+0xaf/0xe0 fs/fuse/inode.c:363 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 773 Comm: khungtaskd Not tainted 4.18.0-rc7+ #177 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2286 Comm: udevd Not tainted 4.18.0-rc7+ #177 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:69 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x26/0x50 kernel/kcov.c:101 Code: 5d c3 66 90 55 65 48 8b 04 25 40 ee 01 00 65 8b 15 8f d5 85 7e 48 89 e5 81 e2 00 01 1f 00 48 8b 75 08 75 2b 8b 90 90 12 00 00 <83> fa 02 75 20 48 8b 88 98 12 00 00 8b 80 94 12 00 00 48 8b 11 48 RSP: 0018:ffff8801ca47f100 EFLAGS: 00000246 RAX: ffff8801ca470600 RBX: ffff8801ccef2240 RCX: ffffffff850af1cf RDX: 0000000000000000 RSI: ffffffff850af1eb RDI: 0000000000000001 RBP: ffff8801ca47f100 R08: ffff8801ca470600 R09: 0000000000000006 R10: ffff8801ca470600 R11: 0000000000000000 R12: 0000000000000008 R13: 1ffff1003948fe25 R14: ffff8801ca47f1c8 R15: 0000000000000000 FS: 00007f4dde8587a0(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001ca987000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: datagram_poll+0x2ab/0x6c0 net/core/datagram.c:850 sock_poll+0x1b7/0x4b0 net/socket.c:1139 vfs_poll include/linux/poll.h:86 [inline] ep_item_poll.isra.14+0x15c/0x400 fs/eventpoll.c:887 ep_send_events_proc+0x347/0xf00 fs/eventpoll.c:1656 ep_scan_ready_list+0x3c5/0xf50 fs/eventpoll.c:699 ep_send_events fs/eventpoll.c:1706 [inline] ep_poll+0x3ef/0x1210 fs/eventpoll.c:1832 do_epoll_wait+0x1b0/0x200 fs/eventpoll.c:2190 __do_sys_epoll_wait fs/eventpoll.c:2200 [inline] __se_sys_epoll_wait fs/eventpoll.c:2197 [inline] __x64_sys_epoll_wait+0x97/0xf0 fs/eventpoll.c:2197 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f4dddf6c943 Code: 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 90 90 90 90 90 90 83 3d b5 dc 2a 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 3b c4 00 00 48 89 04 24 RSP: 002b:00007ffca87594b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007f4dddf6c943 RDX: 0000000000000008 RSI: 00007ffca87595b0 RDI: 000000000000000a RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000bb8 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 0000000002085b60 R15: 000000000207e250 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.290 msecs