loop0: rw=0, want=18442984958116442982, limit=264192 attempt to access beyond end of device loop0: rw=0, want=18442984958116442984, limit=264192 attempt to access beyond end of device loop0: rw=0, want=18442984958116442986, limit=264192 INFO: task syz-executor0:25928 blocked for more than 140 seconds. Not tainted 4.9.123-g8dd3fc2 #27 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D27864 25928 1 0x00000004 ffff880191b5b000 ffff8801b2624540 ffff8801ccd0a4c0 ffff8801c442b000 ffff8801db321c18 ffff8801ba4af4c8 ffffffff839f0dbd ffff880191b5b8c8 ffffed003236b718 ffff880191b5b000 00fffc0000000000 ffff8801db3224e8 Call Trace: [] schedule+0x7f/0x1b0 kernel/sched/core.c:3553 [] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3586 [] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [] mutex_lock_nested+0x326/0x870 kernel/locking/mutex.c:621 [] vfat_lookup+0xd1/0x530 fs/fat/namei_vfat.c:729 [] lookup_slow+0x23e/0x470 fs/namei.c:1668 [] walk_component+0x716/0x1bb0 fs/namei.c:1784 [] link_path_walk+0x889/0x1200 fs/namei.c:2120 [] path_openat+0x1ad/0x3590 fs/namei.c:3533 [] do_filp_open+0x197/0x270 fs/namei.c:3568 [] do_sys_open+0x30d/0x5c0 fs/open.c:1072 [] SYSC_open fs/open.c:1090 [inline] [] SyS_open+0x2d/0x40 fs/open.c:1085 [] 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 getty/3660: #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-executor0/25928: #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: (&sbi->s_lock){+.+.+.}, at: [] vfat_lookup+0xd1/0x530 fs/fat/namei_vfat.c:729 1 lock held by syz-executor0/956: #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 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.123-g8dd3fc2 #27 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801d842fd08 ffffffff81eb9689 0000000000000000 0000000000000000 0000000000000000 0000000000000001 ffffffff810b9fa0 ffff8801d842fd40 ffffffff81ec49c7 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 CPU: 1 PID: 945 Comm: syz-executor0 Not tainted 4.9.123-g8dd3fc2 #27 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801a01e3000 task.stack: ffff8801cf8e8000 RIP: 0010:[] c [] __write_once_size include/linux/compiler.h:272 [inline] RIP: 0010:[] c [] __sanitizer_cov_trace_pc+0x4b/0x50 kernel/kcov.c:108 RSP: 0018:ffff8801cf8eef28 EFLAGS: 00000246 RAX: 0000000000040000 RBX: ffff8801d618df88 RCX: ffffc9000011f000 RDX: 0000000000040000 RSI: ffffffff8143b1ca RDI: ffffffff84434408 RBP: ffff8801cf8eef28 R08: ffff8801a01e3938 R09: 0000000000000001 R10: ffff8801a01e3000 R11: 1ffff1003403c722 R12: 0000000000000001 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8801d618df88 FS: 00007f1314235700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c4288efec0 CR3: 000000018a766000 CR4: 00000000001606f0 DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Stack: ffff8801cf8eef90c ffffffff8143b1cac ffffffff8143b160c ffffed003403c718c ffff8801a01e38c8c 0000000000000041c 0000000000000001c ffff8801cf8eefa0c ffff8801d618df88c 0000000000000001c dffffc0000000000c 0000000000000000c Call Trace: [] rcu_read_lock include/linux/rcupdate.h:876 [inline] [] find_get_entry+0x6a/0x540 mm/filemap.c:1090 [] pagecache_get_page+0x4b/0x720 mm/filemap.c:1201 [] find_get_page_flags include/linux/pagemap.h:264 [inline] [] __find_get_block_slow+0xc2/0x330 fs/buffer.c:212 [] __find_get_block+0x23e/0x4c0 fs/buffer.c:1360 [] __getblk_slow fs/buffer.c:1101 [inline] [] __getblk_gfp+0x189/0x710 fs/buffer.c:1386 [] __bread_gfp+0x2d/0x270 fs/buffer.c:1420 [] sb_bread include/linux/buffer_head.h:300 [inline] [] fat__get_entry+0x4c8/0x8f0 fs/fat/dir.c:100 [] fat_get_entry fs/fat/dir.c:128 [inline] [] fat_search_long+0x277/0x1180 fs/fat/dir.c:477 [] vfat_find+0x134/0x180 fs/fat/namei_vfat.c:708 [] vfat_lookup+0xe1/0x530 fs/fat/namei_vfat.c:731 [] lookup_slow+0x23e/0x470 fs/namei.c:1668 [] walk_component+0x716/0x1bb0 fs/namei.c:1784 [] link_path_walk+0x889/0x1200 fs/namei.c:2120 [] path_openat+0x1ad/0x3590 fs/namei.c:3533 [] do_filp_open+0x197/0x270 fs/namei.c:3568 [] do_sys_open+0x30d/0x5c0 fs/open.c:1072 [] SYSC_openat fs/open.c:1099 [inline] [] SyS_openat+0x30/0x40 fs/open.c:1093 [] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Code: c8b c90 c80 c12 c00 c00 c83 cfa c02 c75 c20 c48 c8b c88 c88 c12 c00 c00 c8b c80 c84 c12 c00 c00 c48 c8b c11 c48 c83 cc2 c01 c48 c39 cd0 c76 c07 c48 c89 c34 cd1 c48 c89 c11 c<5d> cc3 c0f c1f c00 c55 c48 c89 ce5 c41 c57 c41 c56 c41 c55 c41 c54 c53 c48 c89 cf3 c