[release-branch.go1.11] crypto/x509: fix value ownership in isSSLPolicy on macOS

CFDictionaryGetValueIfPresent does not take ownership of the value, so
releasing the properties dictionary before passing the value to CFEqual
can crash. Not really clear why this works most of the time.

See https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFMemoryMgmt/Concepts/Ownership.html

Fixes #32281
Updates #28092
Updates #30763

Change-Id: I5ee7ca276b753a48abc3aedfb78b8af68b448dd4
Reviewed-on: https://go-review.googlesource.com/c/go/+/178537
Reviewed-by: Adam Langley <agl@golang.org>
(cherry picked from commit a3d4655c2435e3777c45f09650539b943bab1c66)
Reviewed-on: https://go-review.googlesource.com/c/go/+/179340
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

diff --git a/src/crypto/x509/root_cgo_darwin.go b/src/crypto/x509/root_cgo_darwin.go
index e6332072d62a50d89398bd4d3677fb9f02efc4aa..1c20f26acb0c51efd35bfee8b28355adf5e844b0 100644 (file)
--- a/src/crypto/x509/root_cgo_darwin.go
+++ b/src/crypto/x509/root_cgo_darwin.go
@@ -16,7 +16,7 @@ package x509
 #include <CoreFoundation/CoreFoundation.h>
 #include <Security/Security.h>
 
-static bool isSSLPolicy(SecPolicyRef policyRef) {
+static Boolean isSSLPolicy(SecPolicyRef policyRef) {
        if (!policyRef) {
                return false;
        }
@@ -24,13 +24,13 @@ static bool isSSLPolicy(SecPolicyRef policyRef) {
        if (properties == NULL) {
                return false;
        }
+       Boolean isSSL = false;
        CFTypeRef value = NULL;
        if (CFDictionaryGetValueIfPresent(properties, kSecPolicyOid, (const void **)&value)) {
-               CFRelease(properties);
-               return CFEqual(value, kSecPolicyAppleSSL);
+               isSSL = CFEqual(value, kSecPolicyAppleSSL);
        }
        CFRelease(properties);
-       return false;
+       return isSSL;
 }
 
 // sslTrustSettingsResult obtains the final kSecTrustSettingsResult value