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From:   zhengbin <zhengbin13@huawei.com>
To:     <john.stultz@linaro.org>, <tglx@linutronix.de>, <sboyd@kernel.org>,
        <linux-kernel@vger.kernel.org>
CC:     <yi.zhang@huawei.com>, <zhangxiaoxu5@huawei.com>
Subject: [PATCH v2] time: compat settimeofday: Validate the values of tv from user
Date:   Sun, 7 Jul 2019 08:51:41 +0800
Message-ID: <1562460701-113301-1-git-send-email-zhengbin13@huawei.com>
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Similar to commit 6ada1fc0e1c4
("time: settimeofday: Validate the values of tv from user"),
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 <zhengbin13@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 7f7d691..5c54ca6 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;
 	}
--
2.7.4