diff --git a/[refs] b/[refs]
index 58141b1ca390..e3fbbc5f54ee 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ab9c0bb8a8c1d71dd303abdaa61ec496128e2fbe
+refs/heads/master: cef53278682eb2604cbd99de64cdb59a8b35235a
diff --git a/trunk/arch/x86/kernel/tlb_uv.c b/trunk/arch/x86/kernel/tlb_uv.c
index b362913f0199..c503b7f04481 100644
--- a/trunk/arch/x86/kernel/tlb_uv.c
+++ b/trunk/arch/x86/kernel/tlb_uv.c
@@ -492,6 +492,8 @@ static ssize_t uv_ptc_proc_write(struct file *file, const char __user *user,
 	long newmode;
 	char optstr[64];
 
+	if (count > 64)
+		return -EINVAL;
 	if (copy_from_user(optstr, user, count))
 		return -EFAULT;
 	optstr[count - 1] = '\0';