tls1_set_groups_list: freeing *pext before overwriting

calling SSL_CTX_set1_groups_list() twice on one SSL_CTX* caused a memory
leak visible in valgrind:
  4 bytes in 1 blocks are definitely lost in loss record 1 of 1
     at 0x4841888: malloc (vg_replace_malloc.c:381)
     by 0x4B1EE96: CRYPTO_memdup (in libcrypto.so.3)
     by 0x48993A0: tls1_set_groups_list (in libssl.so.3)
     by 0x487AA7E: ssl3_ctx_ctrl (in libssl.so.3)
     by 0x1091EA: main (mem_leak.c:10)

  LEAK SUMMARY:
     definitely lost: 4 bytes in 1 blocks

Freeing *pext to fix it.

CLA: trivial

Signed-off-by: Peter Kaestle <peter.kaestle@nokia.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20317)

(cherry picked from commit fcf3a9f7c6a10acb2d92f03aec5e45df7dd712d5)

diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 51c2283db915d792fa3020a2d7cbdc0d91fc9dca..0928a30c2d37b81f8d2ae2a1d00be5de56ea2e69 100644 (file)
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -765,6 +765,7 @@ int tls1_set_groups_list(SSL_CTX *ctx, uint16_t **pext, size_t *pextlen,
     tmparr = OPENSSL_memdup(gcb.gid_arr, gcb.gidcnt * sizeof(*tmparr));
     if (tmparr == NULL)
         goto end;
+    OPENSSL_free(*pext);
     *pext = tmparr;
     *pextlen = gcb.gidcnt;
     ret = 1;