syz-executor1(19347): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor1(19347): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor1(19347): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor1(19347): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor1(19347): getblk(): executed=9 bh_count=0 bh_state=0 INFO: task syz-executor1:5573 blocked for more than 140 seconds. Not tainted 4.19.0-rc8-next-20181019+ #98 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D18128 5573 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3480 schedule+0xfe/0x460 kernel/sched/core.c:3524 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3582 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xaff/0x16f0 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 vfat_lookup+0xf1/0x640 fs/fat/namei_vfat.c:709 syz-executor1(19347): getblk(): executed=9 bh_count=0 bh_state=0 __lookup_slow+0x2b5/0x540 fs/namei.c:1671 lookup_slow+0x57/0x80 fs/namei.c:1688 walk_component+0x92b/0x2590 fs/namei.c:1810 link_path_walk.part.40+0xa61/0x1530 fs/namei.c:2141 link_path_walk fs/namei.c:2072 [inline] path_openat+0x270/0x5150 fs/namei.c:3533 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 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: 0033:0x455570 Code: Bad RIP value. RSP: 002b:00007ffefebc8d50 EFLAGS: 00000206 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455570 RDX: 0000000000000000 RSI: 0000000000090800 RDI: 00000000004bc2ae RBP: 00000000000006f4 R08: 0000000000000001 R09: 0000000000fc2940 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000004 R13: 000000000007826a R14: 00000000000001b5 R15: 0000000000000001 Showing all locks held in the system: 1 lock held by khungtaskd/982: #0: 000000009fc6f265 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5436: #0: 00000000b3a896d4 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5526: #0: 00000000e3c042fd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000765ecd62 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5527: #0: 00000000e47557c6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000004644dfd5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5528: #0: 00000000ed683419 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000041dae008 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5529: #0: 0000000047c7d303 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c6d921c0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5530: #0: 00000000d9a74e84 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000001a81d5ad (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5531: #0: 00000000b8fb69e6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000006c1fe33e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5532: #0: 00000000aeca5714 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000002390a0df (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by syz-executor1/5573: #0: 000000009dd88769 (&sb->s_type->i_mutex_key#26){++++}, at: inode_lock_shared include/linux/fs.h:779 [inline] #0: 000000009dd88769 (&sb->s_type->i_mutex_key#26){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 #1: 0000000025cb4820 (&sbi->s_lock){+.+.}, at: vfat_lookup+0xf1/0x640 fs/fat/namei_vfat.c:709 3 locks held by syz-executor1/19347: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 982 Comm: khungtaskd Not tainted 4.19.0-rc8-next-20181019+ #98 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+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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+0xb39/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.028 msecs NMI backtrace for cpu 0 CPU: 0 PID: 19347 Comm: syz-executor1 Not tainted 4.19.0-rc8-next-20181019+ #98 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:find_held_lock+0x175/0x1c0 kernel/locking/lockdep.c:3469 Code: 00 00 fc ff df 48 8b 55 d0 48 c1 ea 03 0f b6 04 02 84 c0 74 04 3c 03 7e 28 48 8b 45 d0 44 89 38 48 83 c4 10 4c 89 e0 5b 41 5c <41> 5d 41 5e 41 5f 5d c3 45 31 e4 eb c4 e8 69 13 62 00 e9 f5 fe ff RSP: 0018:ffff8801be6ce598 EFLAGS: 00000086 RAX: ffff8801b8422a90 RBX: 1ffff10037cd9cbd RCX: ffff8801be6ce608 RDX: 1ffff10037cd9cc1 RSI: 0000000000000000 RDI: ffff8801b8422aa0 RBP: ffff8801be6ce5b0 R08: 0000000000000000 R09: ffffed003b5c5b4f R10: 0000000000000003 R11: ffff8801dae2da7b R12: ffffffff8aebc520 R13: ffff8801be6ce6c8 R14: ffffffff8939ad40 R15: 0000000000000002 FS: 00007f0735bb7700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb4252c3698 CR3: 00000001cb589000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_release kernel/locking/lockdep.c:3602 [inline] lock_release+0x2a7/0xa10 kernel/locking/lockdep.c:3863 rcu_lock_release include/linux/rcupdate.h:228 [inline] rcu_read_unlock include/linux/rcupdate.h:661 [inline] find_get_entry+0xaae/0x1120 mm/filemap.c:1445 pagecache_get_page+0x12f/0xf00 mm/filemap.c:1518 find_or_create_page include/linux/pagemap.h:322 [inline] grow_dev_page fs/buffer.c:947 [inline] grow_buffers fs/buffer.c:1029 [inline] __getblk_slow fs/buffer.c:1062 [inline] __getblk_gfp+0x4ca/0x1030 fs/buffer.c:1351 __bread_gfp+0x2d/0x310 fs/buffer.c:1385 sb_bread include/linux/buffer_head.h:307 [inline] fat__get_entry+0x5a6/0xa40 fs/fat/dir.c:101 fat_get_entry fs/fat/dir.c:129 [inline] fat_search_long+0x33b/0x1570 fs/fat/dir.c:479 vfat_find+0x16d/0x1a0 fs/fat/namei_vfat.c:697 vfat_lookup+0x107/0x640 fs/fat/namei_vfat.c:711 lookup_open+0x72e/0x1b90 fs/namei.c:3213 do_last fs/namei.c:3324 [inline] path_openat+0x2464/0x5150 fs/namei.c:3534 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0735bb6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000020000040 RDI: ffffffffffffff9c RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0735bb76d4 R13: 00000000004c2eb3 R14: 00000000004d46b0 R15: 00000000ffffffff