From: Sasha Levin <sasha.levin@oracle.com>
To: linux-kernel@vger.kernel.org
Cc: Sasha Levin <sasha.levin@oracle.com>,
John Stultz <john.stultz@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH] time: settimeofday: validate the values of tv fomr user
Date: Mon, 1 Dec 2014 23:04:09 -0500 [thread overview]
Message-ID: <1417493050-13594-5-git-send-email-sasha.levin@oracle.com> (raw)
In-Reply-To: <1417493050-13594-1-git-send-email-sasha.levin@oracle.com>
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 <sasha.levin@oracle.com>
---
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
next prev parent reply other threads:[~2014-12-02 4:04 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-02 4:04 [PATCH] time: do a safe overflow check in ktime_add_safe Sasha Levin
2014-12-02 4:04 ` [PATCH] time: make sure tz_minuteswest is set to a valid value when setting time Sasha Levin
2014-12-02 4:04 ` [PATCH] vfs: calculate seek offsets using unsigned variables Sasha Levin
2014-12-02 4:04 ` [PATCH] mm: fadvise: avoid signed integer overflow calculating offset Sasha Levin
2014-12-02 4:04 ` Sasha Levin [this message]
2014-12-02 11:16 ` [PATCH] time: settimeofday: validate the values of tv fomr user Thomas Gleixner
2014-12-02 4:04 ` [PATCH] fs: sync_file_range: avoid overflowing signed calculation Sasha Levin
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