This is a note to let you know that I've just added the patch titled
rtc: tps6594: Fix integer overflow on 32bit systems
to the 6.13-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:
rtc-tps6594-fix-integer-overflow-on-32bit-systems.patch
and it can be found in the queue-6.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 482a2e3fac14bea5cdc6b7d9a3a2ea00510a74fc
Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Wed Dec 11 12:32:34 2024 +0300
rtc: tps6594: Fix integer overflow on 32bit systems
[ Upstream commit 09c4a610153286cef54d4f0c85398f4e32fc227e ]
The problem is this multiply in tps6594_rtc_set_offset()
tmp = offset * TICKS_PER_HOUR;
The "tmp" variable is an s64 but "offset" is a long in the
(-277774)-277774 range. On 32bit systems a long can hold numbers up to
approximately two billion. The number of TICKS_PER_HOUR is really large,
(32768 * 3600) or roughly a hundred million. When you start multiplying
by a hundred million it doesn't take long to overflow the two billion
mark.
Probably the safest way to fix this is to change the type of
TICKS_PER_HOUR to long long because it's such a large number.
Fixes: 9f67c1e63976 ("rtc: tps6594: Add driver for TPS6594 RTC")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Link: https://lore.kernel.org/r/1074175e-5ecb-4e3d-b721-347d794caa90@stanley.mountain
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/rtc/rtc-tps6594.c b/drivers/rtc/rtc-tps6594.c
index e696676341378..7c6246e3f0292 100644
--- a/drivers/rtc/rtc-tps6594.c
+++ b/drivers/rtc/rtc-tps6594.c
@@ -37,7 +37,7 @@
#define MAX_OFFSET (277774)
// Number of ticks per hour
-#define TICKS_PER_HOUR (32768 * 3600)
+#define TICKS_PER_HOUR (32768 * 3600LL)
// Multiplier for ppb conversions
#define PPB_MULT NANO
