print_req_error: I/O error, dev loop4, sector 56
Buffer I/O error on dev loop4, logical block 6, lost async page write
Buffer I/O error on dev loop4, logical block 7, lost async page write
Buffer I/O error on dev loop4, logical block 8, lost async page write
Buffer I/O error on dev loop4, logical block 9, lost async page write
WARNING: CPU: 0 PID: 9554 at fs/buffer.c:1079 mark_buffer_dirty+0x25c/0x680 fs/buffer.c:1079
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 9554 Comm: syz-executor6 Not tainted 4.17.0-rc5+ #98
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+0x185/0x1d0 lib/dump_stack.c:113
 panic+0x39d/0x940 kernel/panic.c:184
 __warn+0x40f/0x580 kernel/panic.c:536
 report_bug+0x72a/0x880 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap+0x1cc/0x620 arch/x86/kernel/traps.c:298
 do_invalid_op+0x46/0x50 arch/x86/kernel/traps.c:317
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
RIP: 0010:mark_buffer_dirty+0x25c/0x680 fs/buffer.c:1079
RSP: 0018:ffff880145e0f180 EFLAGS: 00010246
RAX: ffffffff81e0e1bc RBX: 0000000000000000 RCX: 0000000000040000
RDX: ffffc900063be000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffff880145e0f1d8 R08: 0000000001080020 R09: 0000000000000002
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8801d6356068
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8801423008d8
 __block_commit_write fs/buffer.c:2036 [inline]
 block_write_end+0x365/0x700 fs/buffer.c:2114
 blkdev_write_end+0x152/0x2c0 fs/block_dev.c:593
 generic_perform_write+0x5eb/0x990 mm/filemap.c:3150
 __generic_file_write_iter+0x43b/0xa10 mm/filemap.c:3264
 blkdev_write_iter+0x3a8/0x5f0 fs/block_dev.c:1910
 do_iter_readv_writev+0x84d/0xa00 include/linux/fs.h:1778
 do_iter_write+0x30d/0xd40 fs/read_write.c:959
 vfs_iter_write+0x118/0x180 fs/read_write.c:972
 iter_file_splice_write+0xbc3/0x1710 fs/splice.c:749
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x19b/0x200 fs/splice.c:1018
 splice_direct_to_actor+0x764/0x1040 fs/splice.c:973
 do_splice_direct+0x335/0x540 fs/splice.c:1061
 do_sendfile+0x1067/0x1e40 fs/read_write.c:1440
 __do_sys_sendfile64 fs/read_write.c:1495 [inline]
 __se_sys_sendfile64 fs/read_write.c:1487 [inline]
 __x64_sys_sendfile64+0x218/0x390 fs/read_write.c:1487
 do_syscall_64+0x154/0x220 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x455a09
RSP: 002b:00007f2af74bcc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f2af74bd6d4 RCX: 0000000000455a09
RDX: 0000000020000000 RSI: 0000000000000013 RDI: 0000000000000013
RBP: 000000000072c0b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000002000005 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000579 R14: 00000000006fc3f8 R15: 0000000000000003
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..