syzbot

------------[ cut here ]------------
WARNING: CPU: 0 PID: 29265 at fs/ext4/inode.c:951 ext4_dio_get_block_overwrite fs/ext4/inode.c:951 [inline]
WARNING: CPU: 0 PID: 29265 at fs/ext4/inode.c:951 ext4_dio_get_block_overwrite+0x8d/0xc0 fs/ext4/inode.c:936
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 29265 Comm: syz-executor.5 Not tainted 4.14.150+ #0
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xca/0x134 lib/dump_stack.c:53
 panic+0x1f1/0x3da kernel/panic.c:183
 __warn.cold+0x2f/0x33 kernel/panic.c:547
 report_bug+0x20a/0x248 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x1bf/0x2d0 arch/x86/kernel/traps.c:295
 invalid_op+0x18/0x40 arch/x86/entry/entry_64.S:963
RIP: 0010:ext4_dio_get_block_overwrite fs/ext4/inode.c:951 [inline]
RIP: 0010:ext4_dio_get_block_overwrite+0x8d/0xc0 fs/ext4/inode.c:936
RSP: 0018:ffff8881af747068 EFLAGS: 00010246
RAX: 0000000000040000 RBX: ffff8881af747210 RCX: 0000000000040000
RDX: ffffffff8175ff5d RSI: ffffc90004b4c000 RDI: ffff8881d635d518
RBP: 0000000000000460 R08: 0000000000000001 R09: 0000000000000001
R10: fffffbfff7585ff5 R11: ffffffffbac2ffab R12: 0000000000000000
R13: ffff8881a132de00 R14: 0000000000000460 R15: ffff88816f443400
 get_more_blocks fs/direct-io.c:718 [inline]
 do_direct_IO fs/direct-io.c:1003 [inline]
 do_blockdev_direct_IO fs/direct-io.c:1336 [inline]
 __blockdev_direct_IO+0x30bd/0xe24e fs/direct-io.c:1422
 ext4_direct_IO_write fs/ext4/inode.c:3730 [inline]
 ext4_direct_IO+0xd32/0x2820 fs/ext4/inode.c:3885
 generic_file_direct_write+0x1e4/0x430 mm/filemap.c:3035
 __generic_file_write_iter+0x209/0x550 mm/filemap.c:3214
 ext4_file_write_iter+0x58f/0xdb0 fs/ext4/file.c:268
 call_write_iter include/linux/fs.h:1798 [inline]
 do_iter_readv_writev+0x379/0x580 fs/read_write.c:679
 do_iter_write fs/read_write.c:958 [inline]
 do_iter_write+0x152/0x550 fs/read_write.c:939
 vfs_iter_write+0x70/0xa0 fs/read_write.c:971
 iter_file_splice_write+0x560/0xa50 fs/splice.c:749
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x118/0x160 fs/splice.c:1018
 splice_direct_to_actor+0x292/0x760 fs/splice.c:973
 do_splice_direct+0x177/0x240 fs/splice.c:1061
 do_sendfile+0x493/0xb20 fs/read_write.c:1445
 SYSC_sendfile64 fs/read_write.c:1506 [inline]
 SyS_sendfile64+0x11f/0x140 fs/read_write.c:1492
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459ef9
RSP: 002b:00007f8c6fbe4c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459ef9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000006
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 00000ffffffff800 R11: 0000000000000246 R12: 00007f8c6fbe56d4
R13: 00000000004c7ab0 R14: 00000000004dd8f0 R15: 00000000ffffffff
Kernel Offset: 0x37400000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
Rebooting in 86400 seconds..