diff --git a/[refs] b/[refs]
index 2c2c3ee65f56..699bbf06e90c 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ed680c4ad478d0fee9740f7d029087f181346564
+refs/heads/master: 0083fc2c50e6c5127c2802ad323adf8143ab7856
diff --git a/trunk/kernel/signal.c b/trunk/kernel/signal.c
index ccf1ceedaebe..f268372c0cc0 100644
--- a/trunk/kernel/signal.c
+++ b/trunk/kernel/signal.c
@@ -2454,11 +2454,9 @@ do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long s
 	stack_t oss;
 	int error;
 
-	if (uoss) {
-		oss.ss_sp = (void __user *) current->sas_ss_sp;
-		oss.ss_size = current->sas_ss_size;
-		oss.ss_flags = sas_ss_flags(sp);
-	}
+	oss.ss_sp = (void __user *) current->sas_ss_sp;
+	oss.ss_size = current->sas_ss_size;
+	oss.ss_flags = sas_ss_flags(sp);
 
 	if (uss) {
 		void __user *ss_sp;
@@ -2501,13 +2499,16 @@ do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long s
 		current->sas_ss_size = ss_size;
 	}
 
+	error = 0;
 	if (uoss) {
 		error = -EFAULT;
-		if (copy_to_user(uoss, &oss, sizeof(oss)))
+		if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss)))
 			goto out;
+		error = __put_user(oss.ss_sp, &uoss->ss_sp) |
+			__put_user(oss.ss_size, &uoss->ss_size) |
+			__put_user(oss.ss_flags, &uoss->ss_flags);
 	}
 
-	error = 0;
 out:
 	return error;
 }