Fix a possible memory leak in ct_move_scts

Instead of trying to move the doomed sct back
to the src stack, which may fail as well, simply
free the sct object, as the src list will be
deleted anyway.

Reviewed-by: Paul Yang <kaishen.yy@antfin.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/22762)

(cherry picked from commit a435d786046fabc85acdb89cbf47f154a09796e1)

diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index a0185cce07fc93e1c4a9c2b813d000c9c6caaaf2..e5603b9130e36ced816af593719a744182db114c 100644 (file)
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -4981,6 +4981,8 @@ IMPLEMENT_OBJ_BSEARCH_GLOBAL_CMP_FN(SSL_CIPHER, SSL_CIPHER, ssl_cipher_id);
  * If |dst| points to a NULL pointer, a new stack will be created and owned by
  * the caller.
  * Returns the number of SCTs moved, or a negative integer if an error occurs.
+ * The |dst| stack is created and possibly partially populated even in case
+ * of error, likewise the |src| stack may be left in an intermediate state.
  */
 static int ct_move_scts(STACK_OF(SCT) **dst, STACK_OF(SCT) *src,
                         sct_source_t origin)
@@ -5000,15 +5002,14 @@ static int ct_move_scts(STACK_OF(SCT) **dst, STACK_OF(SCT) *src,
         if (SCT_set_source(sct, origin) != 1)
             goto err;
 
-        if (sk_SCT_push(*dst, sct) <= 0)
+        if (!sk_SCT_push(*dst, sct))
             goto err;
         scts_moved += 1;
     }
 
     return scts_moved;
  err:
-    if (sct != NULL)
-        sk_SCT_push(src, sct);  /* Put the SCT back */
+    SCT_free(sct);
     return -1;
 }