INFO: task syz-executor1:9575 blocked for more than 140 seconds. Not tainted 5.0.0-rc1-next-20190110 #9 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D25480 9575 7926 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 wb_wait_for_completion+0x1e0/0x2d0 fs/fs-writeback.c:221 sync_inodes_sb+0x335/0x490 fs/fs-writeback.c:2417 sync_inodes_one_sb+0x57/0x70 fs/sync.c:74 iterate_supers+0x149/0x290 fs/super.c:723 ksys_sync+0xdf/0x1d0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 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:00007fb7650abc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 000000000073bfa8 RCX: 0000000000457ec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb7650ac6d4 R13: 00000000004c4272 R14: 00000000004db338 R15: 00000000ffffffff INFO: task syz-executor1:9596 blocked for more than 140 seconds. Not tainted 5.0.0-rc1-next-20190110 #9 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D27096 9596 7926 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 wb_wait_for_completion+0x1e0/0x2d0 fs/fs-writeback.c:221 sync_inodes_sb+0x335/0x490 fs/fs-writeback.c:2417 sync_inodes_one_sb+0x57/0x70 fs/sync.c:74 iterate_supers+0x149/0x290 fs/super.c:723 ksys_sync+0xdf/0x1d0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: 28 c3 e8 aa 20 00 00 eb a8 cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 2e 48 83 ec 18 48 89 6c 24 10 48 <8d> 6c 24 10 48 8b 42 08 48 8b 4a 10 48 89 04 24 48 89 4c 24 08 e8 RSP: 002b:00007fb765069c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 000000000073c0e8 RCX: 0000000000457ec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000000073c0e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb76506a6d4 R13: 00000000004c4272 R14: 00000000004db338 R15: 00000000ffffffff Showing all locks held in the system: 6 locks held by kworker/u4:2/32: 1 lock held by khungtaskd/1040: #0: 00000000ef603c79 (rcu_read_lock){....}, at: debug_show_all_locks+0xc6/0x41d kernel/locking/lockdep.c:4408 1 lock held by rsyslogd/7798: 2 locks held by getty/7889: #0: 00000000380478d4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000089ae792f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7890: #0: 00000000895d6160 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000036f969f1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7891: #0: 000000000555d357 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007bf7631a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7892: #0: 0000000013a9c02b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000000c37667b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7893: #0: 00000000be610b46 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005182abae (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7894: #0: 0000000069b85693 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006ba4bbd2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7895: #0: 00000000d8d23abe (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000de7df9aa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 1 lock held by syz-executor1/9575: #0: 0000000031e6eb9b (&type->s_umount_key#49){.+.+}, at: iterate_supers+0xe2/0x290 fs/super.c:721 1 lock held by syz-executor1/9596: #0: 0000000031e6eb9b (&type->s_umount_key#49){.+.+}, at: iterate_supers+0xe2/0x290 fs/super.c:721 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1040 Comm: khungtaskd Not tainted 5.0.0-rc1-next-20190110 #9 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 32 Comm: kworker/u4:2 Not tainted 5.0.0-rc1-next-20190110 #9 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:format_decode+0x883/0xb00 lib/vsprintf.c:2165 Code: ff e8 61 5b 91 f9 89 de bf 2a 00 00 00 e8 95 5c 91 f9 80 fb 2a 48 8b 85 68 ff ff ff 0f 84 25 01 00 00 49 89 c5 e9 61 fa ff ff 38 5b 91 f9 49 8d 7e c0 e8 9f d5 ff ff 4d 8b 6e c0 c1 e0 08 89 RSP: 0018:ffff8880a96b6320 EFLAGS: 00000097 RAX: 0000000000000000 RBX: ffffffff884c3301 RCX: ffffffff87f0cb47 RDX: 0000000000000005 RSI: 0000000000000005 RDI: 0000000000000005 RBP: ffff8880a96b63c8 R08: ffff8880a9686100 R09: ffffed10152d6cc6 R10: ffffed10152d6cc5 R11: ffff8880a96b6628 R12: ffff8880a96b6448 R13: ffffffff884c3302 R14: ffff8880a96b63a0 R15: 0000000000000035 FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f35280094a8 CR3: 00000000a4c32000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vsnprintf+0x197/0x1b10 lib/vsprintf.c:2348 sprintf+0xc0/0x100 lib/vsprintf.c:2598 print_time kernel/printk/printk.c:1264 [inline] print_prefix kernel/printk/printk.c:1290 [inline] msg_print_text+0x543/0x5d0 kernel/printk/printk.c:1309 console_unlock+0x41e/0x1040 kernel/printk/printk.c:2430 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:237 [inline] __find_get_block fs/buffer.c:1331 [inline] __find_get_block.cold+0xd4/0xfb 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_write_inode+0x33a/0xb70 fs/fat/inode.c:859 fat_write_inode+0x96/0x190 fs/fat/inode.c:908 write_inode fs/fs-writeback.c:1176 [inline] __writeback_single_inode+0xef1/0x1620 fs/fs-writeback.c:1375 writeback_sb_inodes+0x762/0x1260 fs/fs-writeback.c:1580 __writeback_inodes_wb+0x16d/0x3d0 fs/fs-writeback.c:1649 wb_writeback+0xa2d/0xf70 fs/fs-writeback.c:1758 wb_check_start_all fs/fs-writeback.c:1882 [inline] wb_do_writeback fs/fs-writeback.c:1908 [inline] wb_workfn+0xe52/0x16f0 fs/fs-writeback.c:1942 process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153 worker_thread+0x143/0x14a0 kernel/workqueue.c:2296 kthread+0x357/0x430 kernel/kthread.c:247 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352