Fix memory leak when rejecting bogus DH parameters.

While back-patching e0e569e1d, I noted that there were some other
places where we ought to be applying DH_free(); namely, where we
load some DH parameters from a file and then reject them as not
being sufficiently secure.  While it seems really unlikely that
anybody would hit these code paths in production, let alone do
so repeatedly, let's fix it for consistency.

Back-patch to v10 where this code was introduced.

Discussion: https://postgr.es/m/16160-18367e56e9a28264@postgresql.org

diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index cdd8021bc8a9411cb4195040aa55ef24583b221e..bf95836eced1bb2d6e1d21d4d893ad8d4cff9b31 100644 (file)
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -814,6 +814,7 @@ load_dh_file(char *filename, bool isServerStart)
                                (errcode(ERRCODE_CONFIG_FILE_ERROR),
                                 errmsg("invalid DH parameters: %s",
                                                SSLerrmessage(ERR_get_error()))));
+               DH_free(dh);
                return NULL;
        }
        if (codes & DH_CHECK_P_NOT_PRIME)
@@ -821,6 +822,7 @@ load_dh_file(char *filename, bool isServerStart)
                ereport(isServerStart ? FATAL : LOG,
                                (errcode(ERRCODE_CONFIG_FILE_ERROR),
                                 errmsg("invalid DH parameters: p is not prime")));
+               DH_free(dh);
                return NULL;
        }
        if ((codes & DH_NOT_SUITABLE_GENERATOR) &&
@@ -829,6 +831,7 @@ load_dh_file(char *filename, bool isServerStart)
                ereport(isServerStart ? FATAL : LOG,
                                (errcode(ERRCODE_CONFIG_FILE_ERROR),
                                 errmsg("invalid DH parameters: neither suitable generator or safe prime")));
+               DH_free(dh);
                return NULL;
        }