An unvalidated user input is multiplied by a constant, which can result in an undefined behaviour for large values. While this is validated later, we should avoid triggering undefined behaviour.
Signed-off-by: Sasha Levin <[email protected]> --- kernel/time/time.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/time/time.c b/kernel/time/time.c index 9ec4fa5..6f53df7 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -200,6 +200,10 @@ SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv, if (tv) { if (copy_from_user(&user_tv, tv, sizeof(*tv))) return -EFAULT; + + if (user_tv.tv_usec > USEC_PER_SEC || user_tv.tv_usec < 0) + return -EINVAL; + new_ts.tv_sec = user_tv.tv_sec; new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
