[PATCH] Check and validate futex timeval

From: Thomas Gleixner
Date: Sat Mar 25 2006 - 07:54:05 EST


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@xxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>

----

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)


-
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