kworker/u4:1(21): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(24388): getblk(): executed=9 bh_count=0 bh_state=0 kworker/u4:1(21): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(24388): getblk(): executed=9 bh_count=0 bh_state=0 kworker/u4:1(21): getblk(): executed=9 bh_count=0 bh_state=0 INFO: task syz-executor0:5587 blocked for more than 140 seconds. Not tainted 4.19.0-rc7-next-20181015+ #94 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D13832 5587 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 __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 syz-executor0(24388): getblk(): executed=9 bh_count=0 bh_state=0 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:00007ffdf29f6100 EFLAGS: 00000206 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455570 RDX: 0000000000000000 RSI: 0000000000090800 RDI: 00000000004bc2ae RBP: 00000000000006f3 R08: 0000000000000001 R09: 0000000001f84940 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 000000000008ad37 R14: 00000000000001ce R15: 0000000000000000 Showing all locks held in the system: 4 locks held by kworker/u4:1/21: 1 lock held by khungtaskd/983: #0: 0000000070e1c7cd (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4380 1 lock held by rsyslogd/5455: #0: 0000000035d6b82e (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5544: #0: 000000006d678142 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e80d108e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5545: #0: 0000000053c7112a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000001c4f352 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5546: #0: 000000002fa44e79 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000bc3ed78f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5547: #0: 0000000061acf22d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000f77efb96 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5548: #0: 000000003022602d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d889d908 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5549: #0: 000000006bdbc5a6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e7be2982 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5550: #0: 000000006ca8555b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e571f98a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by syz-executor0/5587: #0: 00000000a4938e38 (&sb->s_type->i_mutex_key#24){++++}, at: inode_lock_shared include/linux/fs.h:779 [inline] #0: 00000000a4938e38 (&sb->s_type->i_mutex_key#24){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 #1: 00000000dd0abd6e (&sbi->s_lock){+.+.}, at: vfat_lookup+0xf1/0x640 fs/fat/namei_vfat.c:709 3 locks held by syz-executor0/24388: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 983 Comm: khungtaskd Not tainted 4.19.0-rc7-next-20181015+ #94 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: 1.733 msecs NMI backtrace for cpu 0 CPU: 0 PID: 24388 Comm: syz-executor0 Not tainted 4.19.0-rc7-next-20181015+ #94 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0xd/0x20 kernel/kcov.c:187 Code: d6 0f b7 f7 bf 03 00 00 00 48 89 e5 48 8b 4d 08 e8 88 fe ff ff 5d c3 66 0f 1f 44 00 00 55 89 f2 89 fe bf 05 00 00 00 48 89 e5 <48> 8b 4d 08 e8 6a fe ff ff 5d c3 0f 1f 84 00 00 00 00 00 55 48 89 RSP: 0018:ffff8801c711e7d0 EFLAGS: 00000046 RAX: ffff8801c79360c0 RBX: 0000000000000000 RCX: ffffffff81e19c25 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffff8801c711e7d0 R08: ffff8801c79360c0 R09: fffff94000d628de R10: fffff94000d628de R11: ffffea0006b146f7 R12: 0000000000000000 R13: ffffffff8840fa80 R14: ffffffff8815c5a0 R15: 000000000005d027 FS: 0000000001f84940(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fada1733000 CR3: 00000001cd903000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_preemption_disabled+0x3a/0x280 lib/smp_processor_id.c:15 __this_cpu_preempt_check+0x1c/0x20 lib/smp_processor_id.c:62 lookup_bh_lru fs/buffer.c:1292 [inline] __find_get_block+0x183/0xf10 fs/buffer.c:1321 __getblk_slow fs/buffer.c:1058 [inline] __getblk_gfp+0x3d3/0x1030 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_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: 0033:0x411180 Code: 01 f0 ff ff 0f 83 e0 17 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 2d 4e 63 00 00 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 RSP: 002b:00007ffdf29f5c98 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ffdf29f5cc4 RCX: 0000000000411180 RDX: 00007ffdf29f5cca RSI: 0000000000080001 RDI: 00000000004bcfb9 RBP: 00007ffdf29f5cc0 R08: 0000000000000000 R09: 0000000000000004 R10: 0000000000000075 R11: 0000000000000246 R12: 00000000004bcfb9 R13: 0000000000000000 R14: 00000000000001ce R15: 0000000000000000