Patch "cputime: Prevent 32bit overflow in time[val|spec]_to_cputime()" has been added to the 3.14-stable tree

This is a note to let you know that I've just added the patch titled

cputime: Prevent 32bit overflow in time[val|spec]_to_cputime()

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:
cputime-prevent-32bit-overflow-in-time_to_cputime.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: zengtao <[email protected]>
Date: Tue, 2 Feb 2016 11:38:34 +0800
Subject: cputime: Prevent 32bit overflow in time[val|spec]_to_cputime()

From: zengtao <[email protected]>

commit 0f26922fe5dc5724b1adbbd54b21bad03590b4f3 upstream.

The datatype __kernel_time_t is u32 on 32bit platform, so its subject to overflows in the timeval/timespec to cputime conversion.

Currently the following functions are affected:
1. setitimer()
2. timer_create/timer_settime()
3. sys_clock_nanosleep

This can happen on MIPS32 and ARM32 with "Full dynticks CPU time accounting" enabled, which is required for CONFIG_NO_HZ_FULL.

Enforce u64 conversion to prevent the overflow.

---
 include/asm-generic/cputime_nsecs.h |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

@@ -70,7 +70,7 @@ typedef u64 __nocast cputime64_t;
  */
 static inline cputime_t timespec_to_cputime(const struct timespec *val)
 {
-	u64 ret = val->tv_sec * NSEC_PER_SEC + val->tv_nsec;
+	u64 ret = (u64)val->tv_sec * NSEC_PER_SEC + val->tv_nsec;
 	return (__force cputime_t) ret;
 }
 static inline void cputime_to_timespec(const cputime_t ct, struct timespec *val)

@@ -86,7 +86,8 @@ static inline void cputime_to_timespec(c
  */
 static inline cputime_t timeval_to_cputime(const struct timeval *val)
 {
-	u64 ret = val->tv_sec * NSEC_PER_SEC + val->tv_usec * NSEC_PER_USEC;
+	u64 ret = (u64)val->tv_sec * NSEC_PER_SEC +
+			val->tv_usec * NSEC_PER_USEC;
 	return (__force cputime_t) ret;
 }
 static inline void cputime_to_timeval(const cputime_t ct, struct timeval *val)

Patches currently in stable-queue which might be from [email protected] are

queue-3.14/cputime-prevent-32bit-overflow-in-time_to_cputime.patch