lib/copydir.c: copy_entry(): Use temporary stat buffer

There are no guarantees that fstatat() does not clobber the stat
buffer on errors.

Use a temporary buffer so that the following code sees correct
attributes of the source entry.

Link: <https://github.com/shadow-maint/shadow/issues/973>
Signed-off-by: Enrico Scholz <enrico.scholz@sigma-chemnitz.de>
Reviewed-by: Alejandro Colomar <alx@kernel.org>
Cherry-picked-from: 000619344ddb ("lib/copydir:copy_entry(): use temporary stat buffer")
Link: <https://github.com/shadow-maint/shadow/pull/974>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

diff --git a/lib/copydir.c b/lib/copydir.c
index cc1a30d29707563bf21f5c49cb7d75d9e41e7939..fb93437425840beabea587b7621f72f154198ca5 100644 (file)
--- a/lib/copydir.c
+++ b/lib/copydir.c
@@ -415,6 +415,7 @@ static int copy_entry (const struct path_info *src, const struct path_info *dst,
 {
        int err = 0;
        struct stat sb;
+       struct stat tmp_sb;
        struct link_name *lp;
        struct timespec mt[2];
 
@@ -436,7 +437,7 @@ static int copy_entry (const struct path_info *src, const struct path_info *dst,
                 * If the destination already exists do nothing.
                 * This is after the copy_dir above to still iterate into subdirectories.
                 */
-               if (fstatat(dst->dirfd, dst->name, &sb, AT_SYMLINK_NOFOLLOW) != -1) {
+               if (fstatat(dst->dirfd, dst->name, &tmp_sb, AT_SYMLINK_NOFOLLOW) != -1) {
                        return 0;
                }