[PATCH] Check and validate futex timeval

[Thomas Gleixner <tglx@linutronix.de>]

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: Thomas Gleixner <tglx@tglx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

----

 kernel/futex.c        |    4 +++-
 kernel/futex_compat.c |    4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

Index: linux/kernel/futex.c
===================================================================
--- linux.orig/kernel/futex.c
+++ linux/kernel/futex.c
@@ -1039,9 +1039,11 @@ asmlinkage long sys_futex(u32 __user *ua
 	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;
 	}
 	/*
Index: linux/kernel/futex_compat.c
===================================================================
--- linux.orig/kernel/futex_compat.c
+++ linux/kernel/futex_compat.c
@@ -129,9 +129,11 @@ asmlinkage long compat_sys_futex(u32 __u
 	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)