syz-executor0(13859): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(13859): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(13859): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(13859): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(13859): getblk(): executed=9 bh_count=0 bh_state=0 INFO: task syz-executor0:8474 blocked for more than 140 seconds. Not tainted 4.18.0-next-20180824+ #47 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D21560 8474 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x87c/0x1df0 kernel/sched/core.c:3473 schedule+0xfb/0x450 kernel/sched/core.c:3517 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575 __mutex_lock_common kernel/locking/mutex.c:1003 [inline] __mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088 vfat_lookup+0xf1/0x640 fs/fat/namei_vfat.c:709 __lookup_slow+0x2b5/0x540 fs/namei.c:1671 lookup_slow+0x57/0x80 fs/namei.c:1688 walk_component+0x94a/0x2630 fs/namei.c:1810 link_path_walk.part.42+0xa6e/0x1540 fs/namei.c:2141 link_path_walk fs/namei.c:2072 [inline] path_openat+0x268/0x5300 fs/namei.c:3533 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x584/0x720 fs/open.c:1063 __do_sys_open fs/open.c:1081 [inline] __se_sys_open fs/open.c:1076 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1076 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455190 Code: Bad RIP value. RSP: 002b:00007ffe353921b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455190 RDX: 0000000000000000 RSI: 0000000000090800 RDI: 00000000004c1d68 RBP: 0000000000000223 R08: 0000000000000001 R09: 00000000013ae940 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000d R13: 0000000000054a31 R14: 0000000000000063 R15: badc0ffeebadface Showing all locks held in the system: 1 lock held by khungtaskd/775: #0: 00000000bdb1204a (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436 1 lock held by rsyslogd/4325: #0: 00000000458d9024 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4415: #0: 0000000074cf5ead (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000005cc1b78d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4416: #0: 0000000046ee65e5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000097c38fe3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4417: #0: 0000000079410935 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000f8389df5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4418: #0: 0000000043f761ad (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a8df7937 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4419: #0: 00000000f3f72641 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000001e919ea2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4420: #0: 000000001b9fd71c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000005e7a978c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4421: #0: 00000000f9e6d3b0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000642fee14 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor0/8474: #0: 00000000334f72de (&sb->s_type->i_mutex_key#19){++++}, at: inode_lock_shared include/linux/fs.h:780 [inline] #0: 00000000334f72de (&sb->s_type->i_mutex_key#19){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 #1: 00000000fba1745f (&sbi->s_lock){+.+.}, at: vfat_lookup+0xf1/0x640 fs/fat/namei_vfat.c:709 2 locks held by syz-executor0/13859: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 775 Comm: khungtaskd Not tainted 4.18.0-next-20180824+ #47 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.3+0x48/0x88 lib/nmi_backtrace.c:101 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb39/0x1040 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.520 msecs NMI backtrace for cpu 0 CPU: 0 PID: 13859 Comm: syz-executor0 Not tainted 4.18.0-next-20180824+ #47 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:write_comp_data+0x14/0x70 kernel/kcov.c:116 Code: 4c 89 ef e8 ce 41 3f 00 e9 76 fc ff ff e8 24 bf ca ff 90 90 90 90 55 65 4c 8b 04 25 40 ee 01 00 65 8b 05 5f 20 85 7e 48 89 e5 00 01 1f 00 75 51 41 8b 80 88 12 00 00 83 f8 03 75 45 49 8b 80 RSP: 0018:ffff88018d19e488 EFLAGS: 00000202 RAX: 0000000080000000 RBX: 1ffff10031a33c98 RCX: ffffffff81a19976 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000007 RBP: ffff88018d19e488 R08: ffff8801b5194640 R09: ffffed003b6046de R10: 0000000000000003 R11: 0000000000000002 R12: ffffea0006e8bfc0 R13: ffff88018d19e760 R14: ffffea0006e8bfc8 R15: 0000000000000001 FS: 00007f339f676700(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001ab8e5000 CR4: 00000000001406f0 DR0: 0001000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: __sanitizer_cov_trace_const_cmp8+0x18/0x20 kernel/kcov.c:195 mark_page_accessed+0x246/0xd30 mm/swap.c:380 pagecache_get_page+0x766/0xe40 mm/filemap.c:1529 find_or_create_page include/linux/pagemap.h:322 [inline] grow_dev_page fs/buffer.c:948 [inline] grow_buffers fs/buffer.c:1030 [inline] __getblk_slow fs/buffer.c:1063 [inline] __getblk_gfp+0x4d3/0xe00 fs/buffer.c:1352 __bread_gfp+0x2d/0x310 fs/buffer.c:1386 sb_bread include/linux/buffer_head.h:307 [inline] fat__get_entry+0x59c/0xa30 fs/fat/dir.c:101 fat_get_entry fs/fat/dir.c:129 [inline] fat_search_long+0x33b/0x15d0 fs/fat/dir.c:477 vfat_find+0x16d/0x1a0 fs/fat/namei_vfat.c:697 vfat_lookup+0x107/0x640 fs/fat/namei_vfat.c:711 __lookup_slow+0x2b5/0x540 fs/namei.c:1671 lookup_slow+0x57/0x80 fs/namei.c:1688 walk_component+0x94a/0x2630 fs/namei.c:1810 link_path_walk.part.42+0xa6e/0x1540 fs/namei.c:2141 link_path_walk fs/namei.c:2072 [inline] path_openat+0x268/0x5300 fs/namei.c:3533 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x584/0x720 fs/open.c:1063 __do_sys_open fs/open.c:1081 [inline] __se_sys_open fs/open.c:1076 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1076 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x410dc1 Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 b4 17 00 00 c3 48 83 ec 08 e8 8a fa ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 d3 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007f339f675c80 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000410dc1 RDX: 00000000004c8b2b RSI: 0000000000000002 RDI: 00000000004c2374 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00000000ffffffff R13: 00000000004d4158 R14: 00000000004c8b2b R15: 0000000000000000