a295aef603
The following reproducer
mkdir lower upper work merge
touch lower/old
touch lower/new
mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merge
rm merge/new
mv merge/old merge/new & unlink upper/new
may result in this race:
PROCESS A:
rename("merge/old", "merge/new");
overwrite=true,ovl_lower_positive(old)=true,
ovl_dentry_is_whiteout(new)=true -> flags |= RENAME_EXCHANGE
PROCESS B:
unlink("upper/new");
PROCESS A:
lookup newdentry in new_upperdir
call vfs_rename() with negative newdentry and RENAME_EXCHANGE
Fix by adding the missing check for negative newdentry.
Signed-off-by: Zheng Liang <zhengliang6@huawei.com>
Fixes:
|
||
|---|---|---|
| .. | ||
| copy_up.c | ||
| dir.c | ||
| export.c | ||
| file.c | ||
| inode.c | ||
| Kconfig | ||
| Makefile | ||
| namei.c | ||
| overlayfs.h | ||
| ovl_entry.h | ||
| readdir.c | ||
| super.c | ||
| util.c | ||