INFO: task syz-executor0:20989 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 D27576 20989 7824 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 __rwsem_down_write_failed_common+0xa4d/0x1620 kernel/locking/rwsem-xadd.c:577 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:606 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write_nested+0xa9/0x130 kernel/locking/rwsem.c:195 inode_lock_nested include/linux/fs.h:801 [inline] filename_create+0x1a8/0x5a0 fs/namei.c:3635 user_path_create fs/namei.c:3693 [inline] do_mkdirat+0xcf/0x2f0 fs/namei.c:3831 __do_sys_mkdir fs/namei.c:3855 [inline] __se_sys_mkdir fs/namei.c:3853 [inline] __x64_sys_mkdir+0x5c/0x80 fs/namei.c:3853 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:00007fb104bb7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457ec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020001540 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb104bb86d4 R13: 00000000004bd600 R14: 00000000004d6820 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1040: #0: 0000000085c0ae96 (rcu_read_lock){....}, at: debug_show_all_locks+0xc6/0x41d kernel/locking/lockdep.c:4408 1 lock held by rsyslogd/7698: #0: 000000001a849b60 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1b3/0x1f0 fs/file.c:796 2 locks held by getty/7789: #0: 000000001e0528f6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000003e91f8c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7790: #0: 000000001418c989 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000809e891c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7791: #0: 000000009df935d0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f8fe3687 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7792: #0: 00000000edfcebb4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000044d810cd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7793: #0: 0000000093e4e462 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000059ac39fc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7794: #0: 000000000b0d2bbf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000011d0e4d0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7795: #0: 00000000be4b1fee (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006b2635a2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by syz-executor0/20988: 2 locks held by syz-executor0/20989: #0: 00000000bdcfa8a7 (sb_writers#20){.+.+}, at: sb_start_write include/linux/fs.h:1615 [inline] #0: 00000000bdcfa8a7 (sb_writers#20){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:358 #1: 00000000431e1c6e (&sb->s_type->i_mutex_key#29/1){+.+.}, at: inode_lock_nested include/linux/fs.h:801 [inline] #1: 00000000431e1c6e (&sb->s_type->i_mutex_key#29/1){+.+.}, at: filename_create+0x1a8/0x5a0 fs/namei.c:3635 ============================================= 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: 20988 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:write_comp_data+0x1e/0x70 kernel/kcov.c:122 Code: 48 89 34 d1 48 89 11 5d c3 0f 1f 00 65 4c 8b 04 25 40 ee 01 00 65 8b 05 d0 c0 7f 7e a9 00 01 1f 00 75 51 41 8b 80 e0 12 00 00 <83> f8 03 75 45 49 8b 80 e8 12 00 00 45 8b 80 e4 12 00 00 4c 8b 08 RSP: 0018:ffff888012516768 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff888012516940 RCX: ffffffff87f2774e RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffff888012516770 R08: ffff88805191e700 R09: ffffed1015ce5b90 R10: ffffed1015ce5b8f R11: ffff8880ae72dc7b R12: 0000000000000001 R13: ffff88804d8281c0 R14: ffffea00021af5c0 R15: ffff888012516820 FS: 00007fb104bd9700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000047b97000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: xa_entry include/linux/xarray.h:1004 [inline] xas_descend+0x16e/0x500 lib/xarray.c:198 xas_load+0xef/0x150 lib/xarray.c:234 find_get_entry+0x353/0x1090 mm/filemap.c:1476 pagecache_get_page+0xe5/0x1070 mm/filemap.c:1582 find_get_page_flags include/linux/pagemap.h:279 [inline] __find_get_block_slow fs/buffer.c:205 [inline] __find_get_block fs/buffer.c:1331 [inline] __find_get_block+0x615/0xf20 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_slow+0x2cd/0x560 fs/namei.c:1671 lookup_slow+0x58/0x80 fs/namei.c:1688 walk_component+0x8e5/0x26a0 fs/namei.c:1810 lookup_last fs/namei.c:2273 [inline] path_lookupat.isra.0+0x1f5/0xba0 fs/namei.c:2318 do_o_path fs/namei.c:3508 [inline] path_openat+0x2da0/0x5660 fs/namei.c:3530 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:00007fb104bd8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457ec9 RDX: 0000000000200002 RSI: 00000000200003c0 RDI: ffffffffffffff9c RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb104bd96d4 R13: 00000000004c3e74 R14: 00000000004d6ee0 R15: 00000000ffffffff