attempt to access beyond end of device loop0: rw=0, want=18442984958116442986, limit=1036 INFO: task syz-executor6:13959 blocked for more than 140 seconds. Not tainted 4.9.119-g92e8704 #22 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D28656 13959 30246 0x00000004 ffff8801d00d1800 ffff8801ba9a4540 ffff8801be753480 ffff8801ac188000 ffff8801db321c18 ffff8801aa6ff680 ffffffff839ebdcd ffffffff81235627 0000000000000000 ffff8801d00d20c0 0000000600000007 ffff8801db3224e8 Call Trace: [] schedule+0x7f/0x1b0 kernel/sched/core.c:3553 [] rwsem_down_read_failed+0x1e4/0x320 kernel/locking/rwsem-xadd.c:260 [] call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 [] __down_read arch/x86/include/asm/rwsem.h:65 [inline] [] down_read+0x52/0xb0 kernel/locking/rwsem.c:24 [] inode_lock_shared include/linux/fs.h:776 [inline] [] lookup_slow+0x141/0x470 fs/namei.c:1645 [] walk_component+0x716/0x1bb0 fs/namei.c:1784 [] lookup_last fs/namei.c:2266 [inline] [] path_lookupat.isra.41+0x186/0x410 fs/namei.c:2283 [] filename_lookup.part.55+0x177/0x370 fs/namei.c:2317 [] filename_lookup fs/namei.c:2310 [inline] [] user_path_at_empty+0x53/0x70 fs/namei.c:2578 [] user_path_at include/linux/namei.h:55 [inline] [] vfs_fstatat+0xc6/0x170 fs/stat.c:106 [] vfs_stat fs/stat.c:123 [inline] [] SYSC_newstat+0x86/0xf0 fs/stat.c:270 [] SyS_newstat+0x1d/0x30 fs/stat.c:266 [] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Showing all locks held in the system: 2 locks held by khungtaskd/519: #0: (rcu_read_lock){......}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline] #0: (rcu_read_lock){......}, at: [] watchdog+0x11c/0xa20 kernel/hung_task.c:239 #1: (tasklist_lock){.+.?..}, at: [] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336 2 locks held by rs:main Q:Reg/3662: #0: (&f->f_pos_lock){+.+.+.}, at: [] __fdget_pos+0xac/0xd0 fs/file.c:781 #1: (sb_writers#3){.+.+.+}, at: [] file_start_write include/linux/fs.h:2640 [inline] #1: (sb_writers#3){.+.+.+}, at: [] vfs_write+0x3ae/0x530 fs/read_write.c:556 1 lock held by rsyslogd/3664: #0: (&f->f_pos_lock){+.+.+.}, at: [] __fdget_pos+0xac/0xd0 fs/file.c:781 2 locks held by getty/3760: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.+.}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor6/13955: #0: (sb_writers#15){.+.+.+}, at: [] sb_start_write include/linux/fs.h:1573 [inline] #0: (sb_writers#15){.+.+.+}, at: [] mnt_want_write+0x3f/0xb0 fs/namespace.c:391 #1: (&sb->s_type->i_mutex_key#22/1){+.+.+.}, at: [] inode_lock_nested include/linux/fs.h:801 [inline] #1: (&sb->s_type->i_mutex_key#22/1){+.+.+.}, at: [] lock_rename+0x236/0x290 fs/namei.c:2857 1 lock held by syz-executor6/13959: #0: (&sb->s_type->i_mutex_key#22){++++++}, at: [] inode_lock_shared include/linux/fs.h:776 [inline] #0: (&sb->s_type->i_mutex_key#22){++++++}, at: [] lookup_slow+0x141/0x470 fs/namei.c:1645 1 lock held by syz-executor6/13961: #0: (&sb->s_type->i_mutex_key#22){++++++}, at: [] inode_lock_shared include/linux/fs.h:776 [inline] #0: (&sb->s_type->i_mutex_key#22){++++++}, at: [] lookup_slow+0x141/0x470 fs/namei.c:1645 1 lock held by syz-executor6/13962: #0: (&sb->s_type->i_mutex_key#22){++++++}, at: [] inode_lock_shared include/linux/fs.h:776 [inline] #0: (&sb->s_type->i_mutex_key#22){++++++}, at: [] lookup_slow+0x141/0x470 fs/namei.c:1645 1 lock held by syz-executor6/13963: #0: (&sb->s_type->i_mutex_key#22){++++++}, at: [] inode_lock_shared include/linux/fs.h:776 [inline] #0: (&sb->s_type->i_mutex_key#22){++++++}, at: [] do_last fs/namei.c:3314 [inline] #0: (&sb->s_type->i_mutex_key#22){++++++}, at: [] path_openat+0x17dc/0x3590 fs/namei.c:3534 1 lock held by syz-executor6/13966: #0: (&sb->s_type->i_mutex_key#22){++++++}, at: [] inode_lock include/linux/fs.h:766 [inline] #0: (&sb->s_type->i_mutex_key#22){++++++}, at: [] lock_mount+0x8c/0x2c0 fs/namespace.c:2077 2 locks held by syz-executor6/13967: #0: (sb_writers#15){.+.+.+}, at: [] sb_start_write include/linux/fs.h:1573 [inline] #0: (sb_writers#15){.+.+.+}, at: [] mnt_want_write+0x3f/0xb0 fs/namespace.c:391 #1: (&sb->s_type->i_mutex_key#22/1){+.+.+.}, at: [] inode_lock_nested include/linux/fs.h:801 [inline] #1: (&sb->s_type->i_mutex_key#22/1){+.+.+.}, at: [] lock_rename+0x236/0x290 fs/namei.c:2857 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.119-g92e8704 #22 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801d85f7d08 ffffffff81eb4be9 0000000000000000 0000000000000000 0000000000000000 0000000000000001 ffffffff810b9bd0 ffff8801d85f7d40 ffffffff81ebfee7 0000000000000000 0000000000000000 0000000000000003 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99 [] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60 [] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x6b4/0xa20 kernel/hung_task.c:239 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff839fb8d6