[PATCH] futex: check and validate timevals

The futex timeval is not checked for correctness.  The change does not
break existing applications as the timeval is supplied by glibc (and glibc
always passes a correct value), but the glibc-internal tests for this
functionality fail.
Signed-off-by: NThomas Gleixner <tglx@tglx.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kernel/futex.c

@@ -1039,9 +1039,11 @@ asmlinkage long sys_futex(u32 __user *uaddr, int op, int val,
 	unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
 	int val2 = 0;
 
-	if ((op == FUTEX_WAIT) && utime) {
+	if (utime && (op == FUTEX_WAIT)) {
 		if (copy_from_user(&t, utime, sizeof(t)) != 0)
 			return -EFAULT;
+		if (!timespec_valid(&t))
+			return -EINVAL;
 		timeout = timespec_to_jiffies(&t) + 1;
 	}
 	/*

kernel/futex_compat.c

@@ -129,9 +129,11 @@ asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
 	unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
 	int val2 = 0;
 
-	if ((op == FUTEX_WAIT) && utime) {
+	if (utime && (op == FUTEX_WAIT)) {
 		if (get_compat_timespec(&t, utime))
 			return -EFAULT;
+		if (!timespec_valid(&t))
+			return -EINVAL;
 		timeout = timespec_to_jiffies(&t) + 1;
 	}
 	if (op >= FUTEX_REQUEUE)