This is a note to let you know that I've just added the patch titled
time: settimeofday: Validate the values of tv from user
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
time-settimeofday-validate-the-values-of-tv-from-user.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 6ada1fc0e1c4775de0e043e1bd3ae9d065491aa5 Mon Sep 17 00:00:00 2001
From: Sasha Levin <[email protected]>
Date: Wed, 3 Dec 2014 19:22:48 -0500
Subject: time: settimeofday: Validate the values of tv from user
From: Sasha Levin <[email protected]>
commit 6ada1fc0e1c4775de0e043e1bd3ae9d065491aa5 upstream.
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.
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
[jstultz: include trivial milisecond->microsecond correction noticed
by Andy]
Signed-off-by: John Stultz <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
include/linux/time.h | 13 +++++++++++++
kernel/time.c | 4 ++++
2 files changed, 17 insertions(+)
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -173,6 +173,19 @@ extern void getboottime(struct timespec
extern void monotonic_to_bootbased(struct timespec *ts);
extern void get_monotonic_boottime(struct timespec *ts);
+static inline bool timeval_valid(const struct timeval *tv)
+{
+ /* Dates before 1970 are bogus */
+ if (tv->tv_sec < 0)
+ return false;
+
+ /* Can't have more microseconds then a second */
+ if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
+ return false;
+
+ return true;
+}
+
extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
extern int timekeeping_valid_for_hres(void);
extern u64 timekeeping_max_deferment(void);
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -195,6 +195,10 @@ SYSCALL_DEFINE2(settimeofday, struct tim
if (tv) {
if (copy_from_user(&user_tv, tv, sizeof(*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;
}
Patches currently in stable-queue which might be from [email protected] are
queue-3.14/time-adjtimex-validate-the-adj_frequency-values.patch
queue-3.14/time-settimeofday-validate-the-values-of-tv-from-user.patch
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