* [patch] time: cast ->raw_interval to u64 to avoid shift overflow
@ 2012-10-09 7:18 Dan Carpenter
2012-10-09 19:14 ` John Stultz
2012-10-09 19:50 ` [tip:timers/core] timekeeping: Cast raw_interval " tip-bot for Dan Carpenter
0 siblings, 2 replies; 3+ messages in thread
From: Dan Carpenter @ 2012-10-09 7:18 UTC (permalink / raw)
To: John Stultz; +Cc: Thomas Gleixner, linux-kernel, kernel-janitors
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@oracle.com>
---
I'm not super familiar with this code so please review my work
carefully.
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 5ce06a3..1d1ee67 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1113,7 +1113,7 @@ 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;
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [patch] time: cast ->raw_interval to u64 to avoid shift overflow
2012-10-09 7:18 [patch] time: cast ->raw_interval to u64 to avoid shift overflow Dan Carpenter
@ 2012-10-09 19:14 ` John Stultz
2012-10-09 19:50 ` [tip:timers/core] timekeeping: Cast raw_interval " tip-bot for Dan Carpenter
1 sibling, 0 replies; 3+ messages in thread
From: John Stultz @ 2012-10-09 19:14 UTC (permalink / raw)
To: Dan Carpenter; +Cc: Thomas Gleixner, linux-kernel, kernel-janitors
On 10/09/2012 12:18 AM, Dan Carpenter wrote:
> 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@oracle.com>
Yep. Looks like this would trigger if you had NOZ idle for more then 4
seconds.
Thanks for the audit, and sending this in!
Thomas: Mind queuing this? Probably should be marked for stable too.
Acked-by: John Stultz <johnstul@us.ibm.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* [tip:timers/core] timekeeping: Cast raw_interval to u64 to avoid shift overflow
2012-10-09 7:18 [patch] time: cast ->raw_interval to u64 to avoid shift overflow Dan Carpenter
2012-10-09 19:14 ` John Stultz
@ 2012-10-09 19:50 ` tip-bot for Dan Carpenter
1 sibling, 0 replies; 3+ messages in thread
From: tip-bot for Dan Carpenter @ 2012-10-09 19:50 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, johnstul, tglx, dan.carpenter
Commit-ID: 5b3900cd409466c0070b234d941650685ad0c791
Gitweb: http://git.kernel.org/tip/5b3900cd409466c0070b234d941650685ad0c791
Author: Dan Carpenter <dan.carpenter@oracle.com>
AuthorDate: Tue, 9 Oct 2012 10:18:23 +0300
Committer: Thomas Gleixner <tglx@linutronix.de>
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@oracle.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Link: http://lkml.kernel.org/r/20121009071823.GA19159@elgon.mountain
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
---
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;
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2012-10-09 7:18 [patch] time: cast ->raw_interval to u64 to avoid shift overflow Dan Carpenter
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