This is a note to let you know that I've just added the patch titled
rtc: pcf85063: fix potential OOB write in PCF85063 NVMEM read
to the 5.10-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-pcf85063-fix-potential-oob-write-in-pcf85063-nvm.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit bde7c944d212055d666c6c52f6684bb7587298f0
Author: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Date: Wed Dec 18 20:34:58 2024 +0100
rtc: pcf85063: fix potential OOB write in PCF85063 NVMEM read
[ Upstream commit 3ab8c5ed4f84fa20cd16794fe8dc31f633fbc70c ]
The nvmem interface supports variable buffer sizes, while the regmap
interface operates with fixed-size storage. If an nvmem client uses a
buffer size less than 4 bytes, regmap_read will write out of bounds
as it expects the buffer to point at an unsigned int.
Fix this by using an intermediary unsigned int to hold the value.
Fixes: fadfd092ee91 ("rtc: pcf85063: add nvram support")
Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20241218-rtc-pcf85063-stack-corruption-v1-1-12fd0ee0f046@xxxxxxxxxxxxxx
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c
index 449204d84c61d..dd3336cbb7921 100644
--- a/drivers/rtc/rtc-pcf85063.c
+++ b/drivers/rtc/rtc-pcf85063.c
@@ -328,7 +328,16 @@ static const struct rtc_class_ops pcf85063_rtc_ops_alarm = {
static int pcf85063_nvmem_read(void *priv, unsigned int offset,
void *val, size_t bytes)
{
- return regmap_read(priv, PCF85063_REG_RAM, val);
+ unsigned int tmp;
+ int ret;
+
+ ret = regmap_read(priv, PCF85063_REG_RAM, &tmp);
+ if (ret < 0)
+ return ret;
+
+ *(u8 *)val = tmp;
+
+ return 0;
}
static int pcf85063_nvmem_write(void *priv, unsigned int offset,
