libselinux: do not dereference a NULL pointer when calloc() fails
selabel_is_digest_set() contains the following code:
digest = calloc(1, sizeof(*digest));
if (!digest)
goto err;
/* ... */
err:
free(digest->digest);
If calloc() failed, digest is NULL but is dereferenced when the
execution jumps to label err.
Check that digest is not NULL before freeing its fields.
This issue has been found using clang's static analyzer.
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
diff --git a/libselinux/src/label.c b/libselinux/src/label.c
index 60639cf..3300ddc 100644
--- a/libselinux/src/label.c
+++ b/libselinux/src/label.c
@@ -191,9 +191,11 @@
return NULL;
err:
- free(digest->digest);
- free(digest->specfile_list);
- free(digest);
+ if (digest) {
+ free(digest->digest);
+ free(digest->specfile_list);
+ free(digest);
+ }
return NULL;
}
