WARNING in ext4_dio_get_block_overwrite (2)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 987732fc ANDROID: Add a tracepoint for mapping inode to fu..
git tree: android-4.14
console output: https://syzkaller.appspot.com/x/log.txt?x=1136ec46600000
kernel config: https://syzkaller.appspot.com/x/.config?x=db048054ce6f3d49
dashboard link: https://syzkaller.appspot.com/bug?extid=6eb04881553926e66fd7
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+6eb048...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 10582 at fs/ext4/inode.c:951
ext4_dio_get_block_overwrite fs/ext4/inode.c:951 [inline]
WARNING: CPU: 0 PID: 10582 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: 10582 Comm: syz-executor.0 Not tainted 4.14.140+ #39
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0xca/0x134 lib/dump_stack.c:53
panic+0x1ea/0x3d3 kernel/panic.c:182
__warn.cold+0x2f/0x3a kernel/panic.c:546
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:ffff88819ef47068 EFLAGS: 00010246
RAX: 0000000000040000 RBX: ffff88819ef47210 RCX: 0000000000040000
RDX: ffffffff8175dc6d RSI: ffffc9000bc2c000 RDI: ffff8881d591b318
RBP: 0000000000000050 R08: 0000000000000001 R09: 0000000000000001
R10: fffffbfff1545b05 R11: ffffffff8aa2d82b R12: 0000000000000000
R13: ffff88817781de00 R14: 0000000000000050 R15: ffff88819d58e700
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:3716 [inline]
ext4_direct_IO+0xd32/0x2820 fs/ext4/inode.c:3869
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:1788 [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: 0033:0x459879
RSP: 002b:00007f5b2fe63c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459879
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000006
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000008800000 R11: 0000000000000246 R12: 00007f5b2fe646d4
R13: 00000000004c7065 R14: 00000000004dc6d0 R15: 00000000ffffffff
Kernel Offset: 0x7200000 from 0xffffffff81000000 (relocation range:
0xffffffff80000000-0xffffffffbfffffff)
Rebooting in 86400 seconds..


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.