[tip:timers/core] timekeeping: Cast raw_interval to u64 to avoid shift overflow

From: tip-bot for Dan Carpenter
Date: Tue Oct 09 2012 - 15:50:58 EST


Commit-ID: 5b3900cd409466c0070b234d941650685ad0c791
Gitweb: http://git.kernel.org/tip/5b3900cd409466c0070b234d941650685ad0c791
Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
AuthorDate: Tue, 9 Oct 2012 10:18:23 +0300
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 9 Oct 2012 21:27:14 +0200

timekeeping: Cast raw_interval to u64 to avoid shift overflow

We fixed a bunch of integer overflows in timekeeping code during the 3.6
cycle. I did an audit based on that and found this potential overflow.

Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Acked-by: John Stultz <johnstul@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20121009071823.GA19159@xxxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
kernel/time/timekeeping.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 16280ff..3eb3fc7c 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1045,7 +1045,7 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
accumulate_nsecs_to_secs(tk);

/* Accumulate raw time */
- raw_nsecs = tk->raw_interval << shift;
+ raw_nsecs = (u64)tk->raw_interval << shift;
raw_nsecs += tk->raw_time.tv_nsec;
if (raw_nsecs >= NSEC_PER_SEC) {
u64 raw_secs = raw_nsecs;
--
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