e2fsck: Fix bug which can cause e2fsck -fD to corrupt non-indexed directories

E2fsprogs 1.41.10 introduced a regression (in commit b71e018) where
e2fsck -fD can corrupt non-indexed directories when are exists one or
more file names which alphabetically sort before ".".  This can happen
with ext2 filesystems or for small directories (take less than a
block) which contain filenames that begin with a space or some other
punctuation mark.

Fix this by making sure we never reorder the '.' or '..' entry in the
directory, since they must be first.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/e2fsck/rehash.c b/e2fsck/rehash.c
index 780742e..ceb8543 100644 (file)
--- a/e2fsck/rehash.c
+++ b/e2fsck/rehash.c
@@ -763,7 +763,12 @@ retry_nohash:
 
        /* Sort the list */
 resort:
-       qsort(fd.harray, fd.num_array, sizeof(struct hash_entry), hash_cmp);
+       if (fd.compress)
+               qsort(fd.harray+2, fd.num_array-2, sizeof(struct hash_entry),
+                     hash_cmp);
+       else
+               qsort(fd.harray, fd.num_array, sizeof(struct hash_entry),
+                     hash_cmp);
 
        /*
         * Look for duplicates