property: check return values from the property locking calls.

A failure to obtain a lock would have resulted in much badness, now it results
in a failure return.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/14773)

1 files changed, 19 insertions, 10 deletions

diff --git a/crypto/property/property.c b/crypto/property/property.c
index b6e295e5cd..c424e37bfb 100644
--- a/crypto/property/property.c
+++ b/crypto/property/property.c
@@ -117,17 +117,17 @@ static void ossl_method_free(METHOD *method)
     (*method->free)(method->method);
 }
 
-int ossl_property_read_lock(OSSL_METHOD_STORE *p)
+static __owur int ossl_property_read_lock(OSSL_METHOD_STORE *p)
 {
     return p != NULL ? CRYPTO_THREAD_read_lock(p->lock) : 0;
 }
 
-int ossl_property_write_lock(OSSL_METHOD_STORE *p)
+static __owur int ossl_property_write_lock(OSSL_METHOD_STORE *p)
 {
     return p != NULL ? CRYPTO_THREAD_write_lock(p->lock) : 0;
 }
 
-int ossl_property_unlock(OSSL_METHOD_STORE *p)
+static int ossl_property_unlock(OSSL_METHOD_STORE *p)
 {
     return p != 0 ? CRYPTO_THREAD_unlock(p->lock) : 0;
 }
@@ -246,7 +246,10 @@ int ossl_method_store_add(OSSL_METHOD_STORE *store, const OSSL_PROVIDER *prov,
      * A write lock is used unconditionally because we wend our way down to the
      * property string code which isn't locking friendly.
      */
-    ossl_property_write_lock(store);
+    if (!ossl_property_write_lock(store)) {
+        OPENSSL_free(impl);
+        return 0;
+    }
     ossl_method_cache_flush(store, nid);
     if ((impl->properties = ossl_prop_defn_get(store->ctx, properties)) == NULL) {
         impl->properties = ossl_parse_property(store->ctx, properties);
@@ -298,7 +301,8 @@ int ossl_method_store_remove(OSSL_METHOD_STORE *store, int nid,
     if (nid <= 0 || method == NULL || store == NULL)
         return 0;
 
-    ossl_property_write_lock(store);
+    if (!ossl_property_write_lock(store))
+        return 0;
     ossl_method_cache_flush(store, nid);
     alg = ossl_method_store_retrieve(store, nid);
     if (alg == NULL) {
@@ -349,7 +353,8 @@ int ossl_method_store_fetch(OSSL_METHOD_STORE *store, int nid,
      * This only needs to be a read lock, because queries never create property
      * names or value and thus don't modify any of the property string layer.
      */
-    ossl_property_read_lock(store);
+    if (!ossl_property_read_lock(store))
+        return 0;
     alg = ossl_method_store_retrieve(store, nid);
     if (alg == NULL) {
         ossl_property_unlock(store);
@@ -425,14 +430,16 @@ static void ossl_method_cache_flush(OSSL_METHOD_STORE *store, int nid)
     }
 }
 
-void ossl_method_store_flush_cache(OSSL_METHOD_STORE *store, int all)
+int ossl_method_store_flush_cache(OSSL_METHOD_STORE *store, int all)
 {
     void *arg = (all != 0 ? store->algs : NULL);
 
-    ossl_property_write_lock(store);
+    if (!ossl_property_write_lock(store))
+        return 0;
     ossl_sa_ALGORITHM_doall_arg(store->algs, &impl_cache_flush_alg, arg);
     store->nelem = 0;
     ossl_property_unlock(store);
+    return 1;
 }
 
 IMPLEMENT_LHASH_DOALL_ARG(QUERY, IMPL_CACHE_FLUSH);
@@ -508,7 +515,8 @@ int ossl_method_store_cache_get(OSSL_METHOD_STORE *store, int nid,
     if (nid <= 0 || store == NULL)
         return 0;
 
-    ossl_property_read_lock(store);
+    if (!ossl_property_read_lock(store))
+        return 0;
     alg = ossl_method_store_retrieve(store, nid);
     if (alg == NULL)
         goto err;
@@ -541,7 +549,8 @@ int ossl_method_store_cache_set(OSSL_METHOD_STORE *store, int nid,
     if (prop_query == NULL)
         return 1;
 
-    ossl_property_write_lock(store);
+    if (!ossl_property_write_lock(store))
+        return 0;
     if (store->need_flush)
         ossl_method_cache_flush_some(store);
     alg = ossl_method_store_retrieve(store, nid);