x86/sysctl: Fix NULL pointer dereference in error path

This was introduced by c/s c38869e711 "x86/cpuid: Drop the temporary linear
feature bitmap from struct cpuid_policy", and caught by Coverity.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/arch/x86/sysctl.c b/xen/arch/x86/sysctl.c
index 87da5418413b499666478f1685ee63ed914d8e10..b8c30d4c04b702b8557e083b65b526b9eafa3f04 100644 (file)
--- a/xen/arch/x86/sysctl.c
+++ b/xen/arch/x86/sysctl.c
@@ -230,8 +230,8 @@ long arch_do_sysctl(
         /* Bad featureset index? */
         if ( !p )
             ret = -EINVAL;
-
-        cpuid_policy_to_featureset(p, featureset);
+        else
+            cpuid_policy_to_featureset(p, featureset);
 
         /* Copy the requested featureset into place. */
         if ( !ret && copy_to_guest(sysctl->u.cpu_featureset.features,