bio: check for valid socket when closing

Fixes coverity 271258 Improper use of negative value (NEGATIVE_RETURNS)

Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15943)

diff --git a/crypto/bio/bio_sock2.c b/crypto/bio/bio_sock2.c
index f13f20148bbebd2a83feb23a019686ab081b0d28..b6c95913ce6d050b2bf53acef933aed91d841e73 100644 (file)
--- a/crypto/bio/bio_sock2.c
+++ b/crypto/bio/bio_sock2.c
@@ -335,7 +335,7 @@ int BIO_accept_ex(int accept_sock, BIO_ADDR *addr_, int options)
  */
 int BIO_closesocket(int sock)
 {
-    if (closesocket(sock) < 0)
+    if (sock < 0 || closesocket(sock) < 0)
         return 0;
     return 1;
 }