kvm: vcpu 0: requested 16 ns lapic timer period limited to 200000 ns INFO: task syz-executor0:7718 blocked for more than 120 seconds. Not tainted 4.17.0-rc6+ #65 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D26392 7718 4592 0x00000004 Call Trace: context_switch kernel/sched/core.c:2859 [inline] __schedule+0x801/0x1e30 kernel/sched/core.c:3501 schedule+0xef/0x430 kernel/sched/core.c:3545 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0xe38/0x17f0 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __fdget_pos+0x1a9/0x1e0 fs/file.c:766 fdget_pos include/linux/file.h:67 [inline] ksys_write+0x77/0x250 fs/read_write.c:593 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455a09 RSP: 002b:00007fda800aac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fda800ab6d4 RCX: 0000000000455a09 RDX: 00000000ffffff43 RSI: 0000000020000180 RDI: 0000000000000013 RBP: 000000000072c000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000784 R14: 00000000006ff500 R15: 0000000000000002 Showing all locks held in the system: 2 locks held by khungtaskd/892: #0: 00000000b3c2bbfa (rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: 00000000b3c2bbfa (rcu_read_lock){....}, at: watchdog+0x1ff/0xf60 kernel/hung_task.c:249 #1: 00000000dd24a14f (tasklist_lock){.+.+}, at: debug_show_all_locks+0xde/0x34a kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/4425: #0: 000000009a990149 (&f->f_pos_lock){+.+.}, at: try_to_wake_up+0xca/0x1190 kernel/sched/core.c:1966 2 locks held by getty/4515: #0: 00000000f62e279c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000073c3b01d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4516: #0: 000000004bc9b7ec (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000486542b9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4517: #0: 00000000972c5447 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000005e001277 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4518: #0: 00000000a0a95df8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000000093aeb3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4519: #0: 00000000a70e94c3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000aea69aab (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4520: #0: 000000004c33d742 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000c111faba (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4521: #0: 00000000d6510f1e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000f18b0be4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 1 lock held by syz-executor0/7718: #0: 00000000d44510c6 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1a9/0x1e0 fs/file.c:766 2 locks held by syz-executor0/7719: #0: 00000000aa405ee7 (sb_writers#15){.+.+}, at: sb_start_write include/linux/fs.h:1550 [inline] #0: 00000000aa405ee7 (sb_writers#15){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000fcd57498 (&sb->s_type->i_mutex_key#17){+.+.}, at: inode_lock include/linux/fs.h:713 [inline] #1: 00000000fcd57498 (&sb->s_type->i_mutex_key#17){+.+.}, at: do_last fs/namei.c:3274 [inline] #1: 00000000fcd57498 (&sb->s_type->i_mutex_key#17){+.+.}, at: path_openat+0x123b/0x4e20 fs/namei.c:3501 2 locks held by syz-executor0/7721: #0: 00000000aa405ee7 (sb_writers#15){.+.+}, at: sb_start_write include/linux/fs.h:1550 [inline] #0: 00000000aa405ee7 (sb_writers#15){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000fcd57498 (&sb->s_type->i_mutex_key#17/1){+.+.}, at: inode_lock_nested include/linux/fs.h:748 [inline] #1: 00000000fcd57498 (&sb->s_type->i_mutex_key#17/1){+.+.}, at: filename_create+0x1aa/0x5a0 fs/namei.c:3606 1 lock held by syz-executor0/7722: #0: 00000000d44510c6 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1a9/0x1e0 fs/file.c:766 1 lock held by syz-executor0/7723: #0: 00000000d44510c6 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1a9/0x1e0 fs/file.c:766 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 892 Comm: khungtaskd Not tainted 4.17.0-rc6+ #65 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+0x1b9/0x294 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 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:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0xc10/0xf60 kernel/hung_task.c:249 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7717 Comm: syz-executor0 Not tainted 4.17.0-rc6+ #65 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:match_held_lock+0x89/0x8b0 kernel/locking/lockdep.c:3492 RSP: 0018:ffff8801c8236720 EFLAGS: 00000046 RAX: 1ffff10036640d70 RBX: ffff8801b3206b70 RCX: ffffc900020b1000 RDX: dffffc0000000000 RSI: ffffffff88d8e560 RDI: ffff8801b3206b80 RBP: ffff8801c8236810 R08: ffff8801b32062c0 R09: ffffed003b5c46d2 R10: 0000000000000003 R11: 0000000000000004 R12: 1ffff10039046ce9 R13: ffff8801b3206b70 R14: ffff8801c82367e8 R15: 0000000000000003 FS: 00007fda800cc700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000189a7c000 CR4: 00000000001406f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: __lock_is_held+0xb5/0x140 kernel/locking/lockdep.c:3740 lock_is_held_type+0x121/0x210 kernel/locking/lockdep.c:3958 lock_is_held include/linux/lockdep.h:344 [inline] ___might_sleep+0x2c0/0x320 kernel/sched/core.c:6149 __might_sleep+0x95/0x190 kernel/sched/core.c:6137 lock_page include/linux/pagemap.h:481 [inline] pagecache_get_page+0x76c/0xe20 mm/filemap.c:1554 find_or_create_page include/linux/pagemap.h:322 [inline] grow_dev_page fs/buffer.c:940 [inline] grow_buffers fs/buffer.c:1009 [inline] __getblk_slow fs/buffer.c:1036 [inline] __getblk_gfp+0x39e/0xaf0 fs/buffer.c:1313 __bread_gfp+0x2d/0x310 fs/buffer.c:1347 sb_bread include/linux/buffer_head.h:309 [inline] fat12_ent_bread+0x14e/0x3d0 fs/fat/fatent.c:75 fat_ent_read_block fs/fat/fatent.c:441 [inline] fat_alloc_clusters+0x8bf/0x16b0 fs/fat/fatent.c:489 fat_add_cluster+0x72/0x140 fs/fat/inode.c:101 __fat_get_block fs/fat/inode.c:148 [inline] fat_get_block+0x373/0xaf0 fs/fat/inode.c:177 __block_write_begin_int+0x505/0x1ad0 fs/buffer.c:1958 __block_write_begin fs/buffer.c:2008 [inline] block_write_begin+0xd2/0x350 fs/buffer.c:2067 cont_write_begin+0x531/0x820 fs/buffer.c:2417 fat_write_begin+0x8d/0x120 fs/fat/inode.c:223 generic_perform_write+0x39a/0x6a0 mm/filemap.c:3139 __generic_file_write_iter+0x4b9/0x630 mm/filemap.c:3232 generic_file_write_iter+0x430/0x850 mm/filemap.c:3292 call_write_iter include/linux/fs.h:1784 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x64d/0x960 fs/read_write.c:487 vfs_write+0x1f8/0x560 fs/read_write.c:549 ksys_write+0xf9/0x250 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455a09 RSP: 002b:00007fda800cbc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fda800cc6d4 RCX: 0000000000455a09 RDX: 0000000000000801 RSI: 0000000020000280 RDI: 0000000000000013 RBP: 000000000072bf50 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000780 R14: 00000000006ff4a0 R15: 0000000000000001 Code: f1 f1 f1 f1 c7 40 04 00 f2 f2 f2 c7 40 08 f2 f2 f2 f2 c7 40 0c 00 f2 f2 f2 c7 40 10 f3 f3 f3 f3 48 89 f8 48 c1 e8 03 80 3c 10 00 <0f> 85 08 05 00 00 49 39 75 10 0f 84 6b 02 00 00 48 b8 00 00 00 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.347 msecs