Commit-ID: 9176ab1b848059a0cd9caf39f0cebaa1b7ec5ec2 Gitweb: https://git.kernel.org/tip/9176ab1b848059a0cd9caf39f0cebaa1b7ec5ec2 Author: zhengbin <zhengbi...@huawei.com> AuthorDate: Sun, 7 Jul 2019 08:51:41 +0800 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Sun, 7 Jul 2019 12:05:40 +0200
time: Validate user input in compat_settimeofday() The user value is validated after converting the timeval to a timespec, but for a wide range of negative tv_usec values the multiplication overflow turns them in positive numbers. So the 'validated later' is not catching the invalid input. Signed-off-by: zhengbin <zhengbi...@huawei.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Link: https://lkml.kernel.org/r/1562460701-113301-1-git-send-email-zhengbi...@huawei.com --- kernel/time/time.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/time/time.c b/kernel/time/time.c index 7f7d6914ddd5..5c54ca632d08 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -251,6 +251,10 @@ COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv, if (tv) { if (compat_get_timeval(&user_tv, tv)) return -EFAULT; + + if (!timeval_valid(&user_tv)) + return -EINVAL; + new_ts.tv_sec = user_tv.tv_sec; new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; }
