From 1db0bbdc76cfd715b60a155220328c15409cf1aa Mon Sep 17 00:00:00 2001 From: "Dr. Stephen Henson" Date: Wed, 4 Jan 2012 19:00:28 +0000 Subject: [PATCH] Fix double free in policy check code (CVE-2011-4109) --- CHANGES | 3 +++ crypto/x509v3/pcy_map.c | 10 ++++++---- crypto/x509v3/pcy_tree.c | 5 ++++- 3 files changed, 13 insertions(+), 5 deletions(-) diff --git a/CHANGES b/CHANGES index ae0b41c843..cf32f605eb 100644 --- a/CHANGES +++ b/CHANGES @@ -4,6 +4,9 @@ Changes between 0.9.8r and 0.9.8s [xx XXX xxxx] + *) Stop policy check failure freeing same buffer twice. (CVE-2011-4109) + [Ben Laurie, Kasper ] + *) Clear bytes used for block padding of SSL 3.0 records. (CVE-2011-4576) [Adam Langley (Google)] diff --git a/crypto/x509v3/pcy_map.c b/crypto/x509v3/pcy_map.c index f28796e6d4..acd2ede6f3 100644 --- a/crypto/x509v3/pcy_map.c +++ b/crypto/x509v3/pcy_map.c @@ -70,8 +70,6 @@ static int ref_cmp(const X509_POLICY_REF * const *a, static void policy_map_free(X509_POLICY_REF *map) { - if (map->subjectDomainPolicy) - ASN1_OBJECT_free(map->subjectDomainPolicy); OPENSSL_free(map); } @@ -95,6 +93,7 @@ int policy_cache_set_mapping(X509 *x, POLICY_MAPPINGS *maps) { POLICY_MAPPING *map; X509_POLICY_REF *ref = NULL; + ASN1_OBJECT *subjectDomainPolicyRef; X509_POLICY_DATA *data; X509_POLICY_CACHE *cache = x->policy_cache; int i; @@ -153,13 +152,16 @@ int policy_cache_set_mapping(X509 *x, POLICY_MAPPINGS *maps) if (!sk_ASN1_OBJECT_push(data->expected_policy_set, map->subjectDomainPolicy)) goto bad_mapping; + /* map->subjectDomainPolicy will be freed when + * cache->data is freed. Set it to NULL to avoid double-free. */ + subjectDomainPolicyRef = map->subjectDomainPolicy; + map->subjectDomainPolicy = NULL; ref = OPENSSL_malloc(sizeof(X509_POLICY_REF)); if (!ref) goto bad_mapping; - ref->subjectDomainPolicy = map->subjectDomainPolicy; - map->subjectDomainPolicy = NULL; + ref->subjectDomainPolicy = subjectDomainPolicyRef; ref->data = data; if (!sk_X509_POLICY_REF_push(cache->maps, ref)) diff --git a/crypto/x509v3/pcy_tree.c b/crypto/x509v3/pcy_tree.c index 89f84bfa18..92ad0a2b39 100644 --- a/crypto/x509v3/pcy_tree.c +++ b/crypto/x509v3/pcy_tree.c @@ -612,6 +612,10 @@ int X509_policy_check(X509_POLICY_TREE **ptree, int *pexplicit_policy, case 2: return 1; + /* Some internal error */ + case -1: + return -1; + /* Some internal error */ case 0: return 0; @@ -691,4 +695,3 @@ int X509_policy_check(X509_POLICY_TREE **ptree, int *pexplicit_policy, return 0; } - -- 2.25.1