* [PATCH 6.6 144/341] hwmon: (pc87360) Bounds check data->innr usage
[not found] <20240827143843.399359062@linuxfoundation.org>
@ 2024-08-27 14:36 ` Greg Kroah-Hartman
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From: Greg Kroah-Hartman @ 2024-08-27 14:36 UTC (permalink / raw)
To: stable
Cc: Greg Kroah-Hartman, patches, Jim Cromie, Jean Delvare,
Guenter Roeck, linux-hwmon, Kees Cook, Gustavo A. R. Silva,
Sasha Levin
6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kees Cook <keescook@chromium.org>
[ Upstream commit 4265eb062a7303e537ab3792ade31f424c3c5189 ]
Without visibility into the initializers for data->innr, GCC suspects
using it as an index could walk off the end of the various 14-element
arrays in data. Perform an explicit clamp to the array size. Silences
the following warning with GCC 12+:
../drivers/hwmon/pc87360.c: In function 'pc87360_update_device':
../drivers/hwmon/pc87360.c:341:49: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
341 | data->in_max[i] = pc87360_read_value(data,
| ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
342 | LD_IN, i,
| ~~~~~~~~~
343 | PC87365_REG_IN_MAX);
| ~~~~~~~~~~~~~~~~~~~
../drivers/hwmon/pc87360.c:209:12: note: at offset 255 into destination object 'in_max' of size 14
209 | u8 in_max[14]; /* Register value */
| ^~~~~~
Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-hwmon@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20231130200207.work.679-kees@kernel.org
[groeck: Added comment into code clarifying context]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hwmon/pc87360.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/hwmon/pc87360.c b/drivers/hwmon/pc87360.c
index a4adc8bd531ff..534a6072036c9 100644
--- a/drivers/hwmon/pc87360.c
+++ b/drivers/hwmon/pc87360.c
@@ -323,7 +323,11 @@ static struct pc87360_data *pc87360_update_device(struct device *dev)
}
/* Voltages */
- for (i = 0; i < data->innr; i++) {
+ /*
+ * The min() below does not have any practical meaning and is
+ * only needed to silence a warning observed with gcc 12+.
+ */
+ for (i = 0; i < min(data->innr, ARRAY_SIZE(data->in)); i++) {
data->in_status[i] = pc87360_read_value(data, LD_IN, i,
PC87365_REG_IN_STATUS);
/* Clear bits */
--
2.43.0
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