e2fsck: fix e2fsck -D for encrypted directories

If the directory entry is encrypted there may be embedded NUL
characters; hence, we should use memcmp instead of strncmp when
comparing strings.  Otherwise, e2fsck can erroneously report that a
directory have duplicant entries when doing an e2fsck -D check.

Reported-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/e2fsck/rehash.c b/e2fsck/rehash.c
index 22a58f3..77129e5 100644 (file)
--- a/e2fsck/rehash.c
+++ b/e2fsck/rehash.c
@@ -219,7 +219,7 @@ static EXT2_QSORT_TYPE name_cmp(const void *a, const void *b)
        if (min_len > he_b_len)
                min_len = he_b_len;
 
-       ret = strncmp(he_a->dir->name, he_b->dir->name, min_len);
+       ret = memcmp(he_a->dir->name, he_b->dir->name, min_len);
        if (ret == 0) {
                if (he_a_len > he_b_len)
                        ret = 1;
@@ -386,7 +386,7 @@ static int duplicate_search_and_fix(e2fsck_t ctx, ext2_filsys fs,
                if (!ent->dir->inode ||
                    (ext2fs_dirent_name_len(ent->dir) !=
                     ext2fs_dirent_name_len(prev->dir)) ||
-                   strncmp(ent->dir->name, prev->dir->name,
+                   memcmp(ent->dir->name, prev->dir->name,
                             ext2fs_dirent_name_len(ent->dir)))
                        continue;
                pctx.dirent = ent->dir;
@@ -404,7 +404,7 @@ static int duplicate_search_and_fix(e2fsck_t ctx, ext2_filsys fs,
                        if ((i==j) ||
                            (new_len !=
                             (unsigned) ext2fs_dirent_name_len(fd->harray[j].dir)) ||
-                           strncmp(new_name, fd->harray[j].dir->name, new_len))
+                           memcmp(new_name, fd->harray[j].dir->name, new_len))
                                continue;
                        mutate_name(new_name, &new_len);