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| author | Oleksij Rempel <o.rempel@pengutronix.de> | 2024-12-18 20:34:58 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-02-08 09:58:01 +0100 |
| commit | e5e06455760f2995b16a176033909347929d1128 (patch) | |
| tree | 9bcd1e9dd69a339f9caafb3cfd0e2a0e364717b0 /drivers/rtc | |
| parent | 5127f3cbfc78a7b301b86328247230bec47e0bb3 (diff) | |
| download | linux-e5e06455760f2995b16a176033909347929d1128.tar.gz linux-e5e06455760f2995b16a176033909347929d1128.tar.bz2 linux-e5e06455760f2995b16a176033909347929d1128.zip | |
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@pengutronix.de>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.kernel.org/r/20241218-rtc-pcf85063-stack-corruption-v1-1-12fd0ee0f046@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-pcf85063.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c index fdbc07f14036..905986c61655 100644 --- a/drivers/rtc/rtc-pcf85063.c +++ b/drivers/rtc/rtc-pcf85063.c @@ -322,7 +322,16 @@ static const struct rtc_class_ops pcf85063_rtc_ops = { 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, |