INFO: task syz-executor0:10710 blocked for more than 140 seconds. Not tainted 5.0.0-rc1-next-20190111 #10 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D27128 10710 7707 0x00000004 Call Trace: context_switch kernel/sched/core.c:2834 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3475 schedule+0xfe/0x350 kernel/sched/core.c:3519 d_wait_lookup fs/dcache.c:2408 [inline] d_alloc_parallel+0x143c/0x1f10 fs/dcache.c:2490 lookup_open+0x57c/0x1b80 fs/namei.c:3147 do_last fs/namei.c:3324 [inline] path_openat+0x25f6/0x5660 fs/namei.c:3534 do_filp_open+0x26f/0x370 fs/namei.c:3564 do_sys_open+0x59a/0x7c0 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+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007f9d82453c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457ec9 RDX: 0000000000000002 RSI: 0000000020000240 RDI: ffffffffffffff9c RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9d824546d4 R13: 00000000004c3f5f R14: 00000000004d7060 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1040: #0: 00000000fe134cc0 (rcu_read_lock){....}, at: debug_show_all_locks+0xc6/0x41d kernel/locking/lockdep.c:4408 1 lock held by rsyslogd/7559: 2 locks held by getty/7671: #0: 000000003727fb41 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000cb4d0913 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7672: #0: 00000000088b26a5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006bb8aefd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7673: #0: 00000000fdcc64c6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000910f9143 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7674: #0: 00000000162daa2a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000029f67df6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7675: #0: 000000006689a7dc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000048f9f5f0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7676: #0: 000000007551fdf3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b1e0664d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7677: #0: 0000000001f470ae (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000aa5beffd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by syz-executor0/7707: #0: 0000000023c1abd2 (&sb->s_type->i_mutex_key#24){++++}, at: inode_lock_shared include/linux/fs.h:776 [inline] #0: 0000000023c1abd2 (&sb->s_type->i_mutex_key#24){++++}, at: lookup_slow+0x4a/0x80 fs/namei.c:1687 #1: 00000000ec862e23 (&sbi->s_lock){+.+.}, at: vfat_lookup+0xed/0x6b0 fs/fat/namei_vfat.c:709 7 locks held by syz-executor0/10703: 2 locks held by syz-executor0/10710: #0: 000000003d4f1502 (sb_writers#16){.+.+}, at: sb_start_write include/linux/fs.h:1615 [inline] #0: 000000003d4f1502 (sb_writers#16){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:358 #1: 0000000023c1abd2 (&sb->s_type->i_mutex_key#24){++++}, at: inode_lock_shared include/linux/fs.h:776 [inline] #1: 0000000023c1abd2 (&sb->s_type->i_mutex_key#24){++++}, at: do_last fs/namei.c:3323 [inline] #1: 0000000023c1abd2 (&sb->s_type->i_mutex_key#24){++++}, at: path_openat+0x25da/0x5660 fs/namei.c:3534 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1040 Comm: khungtaskd Not tainted 5.0.0-rc1-next-20190111 #10 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+0x1db/0x2d0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0xbbb/0x1170 kernel/hung_task.c:287 kthread+0x357/0x430 kernel/kthread.c:247 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10703 Comm: syz-executor0 Not tainted 5.0.0-rc1-next-20190111 #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:io_serial_in+0x6b/0x90 drivers/tty/serial/8250/8250_port.c:450 Code: e9 00 00 00 49 8d 7c 24 38 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 d3 e3 80 3c 02 00 75 17 41 03 5c 24 38 89 da ec <5b> 0f b6 c0 41 5c 5d c3 e8 08 ea e2 fd eb c2 e8 61 ea e2 fd eb e2 RSP: 0018:ffff88804ea2e9f0 EFLAGS: 00000002 RAX: dffffc0000000060 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: ffffffff83e394d1 RDI: ffffffff8bf7cbf8 RBP: ffff88804ea2ea00 R08: ffff88809a5e6040 R09: ffffed1009d45d45 R10: ffffed1009d45d44 R11: 0000000000000003 R12: ffffffff8bf7cbc0 R13: 0000000000000020 R14: ffffffff8bf7cbc0 R15: fffffbfff17ef981 FS: 00007f9d82475700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f69c001a0d8 CR3: 0000000099767000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_in drivers/tty/serial/8250/8250.h:111 [inline] wait_for_xmitr+0xa7/0x250 drivers/tty/serial/8250/8250_port.c:2028 serial8250_console_putchar+0x20/0x60 drivers/tty/serial/8250/8250_port.c:3199 uart_console_write+0x57/0x120 drivers/tty/serial/serial_core.c:1907 serial8250_console_write+0x6d5/0xab0 drivers/tty/serial/8250/8250_port.c:3263 univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:586 call_console_drivers kernel/printk/printk.c:1784 [inline] console_unlock+0xc9a/0x1040 kernel/printk/printk.c:2455 vprintk_emit+0x370/0x960 kernel/printk/printk.c:1978 vprintk_default+0x28/0x30 kernel/printk/printk.c:2005 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2038 __find_get_block_slow fs/buffer.c:231 [inline] __find_get_block fs/buffer.c:1331 [inline] __find_get_block.cold+0x36/0xfb fs/buffer.c:1325 __getblk_slow fs/buffer.c:1058 [inline] __getblk_gfp+0x3c2/0x1140 fs/buffer.c:1357 __bread_gfp+0x2f/0x300 fs/buffer.c:1391 sb_bread include/linux/buffer_head.h:307 [inline] fat__get_entry+0x586/0xa40 fs/fat/dir.c:101 fat_get_entry fs/fat/dir.c:129 [inline] fat_search_long+0x345/0x17d0 fs/fat/dir.c:479 vfat_find+0x10e/0x140 fs/fat/namei_vfat.c:697 vfat_lookup+0x10a/0x6b0 fs/fat/namei_vfat.c:711 lookup_open+0x726/0x1b80 fs/namei.c:3213 do_last fs/namei.c:3324 [inline] path_openat+0x25f6/0x5660 fs/namei.c:3534 do_filp_open+0x26f/0x370 fs/namei.c:3564 do_sys_open+0x59a/0x7c0 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+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f9d82474c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457ec9 RDX: 0000000000000002 RSI: 0000000020000240 RDI: ffffffffffffff9c RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9d824756d4 R13: 00000000004c3f5f R14: 00000000004d7060 R15: 00000000ffffffff