x86, pat: Proper init of memtype subtree_max_end

subtree_max_end that was recently added to struct memtype was not getting
properly initialized resulting in

WARNING: kmemcheck: Caught 64-bit read from uninitialized memory
in memtype_rb_augment_cb()
reported here
https://bugzilla.kernel.org/show_bug.cgi?id=16092

This change fixes the problem.

Reported-by: Christian Casteyde <casteyde.christian@free.fr>
Tested-by: Christian Casteyde <casteyde.christian@free.fr>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
LKML-Reference: <1276217101-11515-1-git-send-email-venki@google.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>

2 files changed, 2 insertions, 1 deletions

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index acc15b23b743..64121a18b8cb 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -302,7 +302,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
                 return -EINVAL;
         }
 
-        new  = kmalloc(sizeof(struct memtype), GFP_KERNEL);
+        new  = kzalloc(sizeof(struct memtype), GFP_KERNEL);
         if (!new)
                 return -ENOMEM;
 
diff --git a/arch/x86/mm/pat_rbtree.c b/arch/x86/mm/pat_rbtree.c
index f537087bb740..f20eeec85a86 100644
--- a/arch/x86/mm/pat_rbtree.c
+++ b/arch/x86/mm/pat_rbtree.c
@@ -226,6 +226,7 @@ int rbt_memtype_check_insert(struct memtype *new, unsigned long *ret_type)
                 if (ret_type)
                         new->type = *ret_type;
 
+                new->subtree_max_end = new->end;
                 memtype_rb_insert(&memtype_rbroot, new);
         }
         return err;