BUG/MEDIUM: server: fix potential null-deref after previous fix

A valid build warning was reported in the CI with latest commit b40ce97ecc
("BUG/MEDIUM: server: fix crash after duplicate GUID insertion"). Indeed,
if the first test in the function fails, we branch to the err label
with guid==NULL and will crash there. Let's just test guid before
dereferencing it for freeing.

This needs to be backported to 3.0 as well since the commit above was
meant to go there.

diff --git a/src/guid.c b/src/guid.c
index f2bc99cf6da130d43d5a6cc973645ca74ba12021..01f52c16958d7b13141fb8ecb927237e7da79b73 100644 (file)
--- a/src/guid.c
+++ b/src/guid.c
@@ -75,7 +75,8 @@ int guid_insert(enum obj_type *objt, const char *uid, char **errmsg)
        return 0;
 
  err:
-       ha_free(&guid->node.key);
+       if (guid)
+               ha_free(&guid->node.key);
        ha_free(&dup_name);
        return 1;
 }