From: Peter Krempa <pkrempa@redhat.com>
Date: Mon, 1 Feb 2021 11:52:07 +0000 (+0100)
Subject: qemuDomainMasterKeyCreate: Don't use VIR_DISPOSE_N on failure
X-Git-Tag: v7.1.0-rc1~328
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ac4b55c99da546ccfa7b8d5aef723ecdb8593212;p=thirdparty%2Flibvirt.git

qemuDomainMasterKeyCreate: Don't use VIR_DISPOSE_N on failure

When virRandomBytes fails we don't get any random bytes and even if we
did they don't have to be treated as secret as they weren't used in any
way.

Add a temporary variable with automatic freeing for the secret buffer
and assign it only on success.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
---

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 0c078a9388..2c34307c82 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -562,18 +562,19 @@ int
 qemuDomainMasterKeyCreate(virDomainObjPtr vm)
 {
     qemuDomainObjPrivatePtr priv = vm->privateData;
+    g_autofree uint8_t *key = NULL;
 
     /* If we don't have the capability, then do nothing. */
     if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_OBJECT_SECRET))
         return 0;
 
-    priv->masterKey = g_new0(uint8_t, QEMU_DOMAIN_MASTER_KEY_LEN);
-    priv->masterKeyLen = QEMU_DOMAIN_MASTER_KEY_LEN;
+    key = g_new0(uint8_t, QEMU_DOMAIN_MASTER_KEY_LEN);
 
-    if (virRandomBytes(priv->masterKey, priv->masterKeyLen) < 0) {
-        VIR_DISPOSE_N(priv->masterKey, priv->masterKeyLen);
+    if (virRandomBytes(key, QEMU_DOMAIN_MASTER_KEY_LEN) < 0)
         return -1;
-    }
+
+    priv->masterKey = g_steal_pointer(&key);
+    priv->masterKeyLen = QEMU_DOMAIN_MASTER_KEY_LEN;
 
     return 0;
 }