Commit eee213da authored by Abdurrahman Hussain's avatar Abdurrahman Hussain Committed by Guenter Roeck
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hwmon: (pmbus/adm1266) widen blackbox-info buffer to I2C_SMBUS_BLOCK_MAX 



adm1266_nvmem_read_blackbox() declares a 5-byte stack buffer and
passes it to i2c_smbus_read_block_data() to retrieve the 4-byte
BLACKBOX_INFO response.  i2c_smbus_read_block_data() does not honour
caller buffer sizes -- it memcpy()s data.block[0] bytes from the
SMBus transaction (where data.block[0] is the length byte returned by
the slave device, up to I2C_SMBUS_BLOCK_MAX = 32):

	memcpy(values, &data.block[1], data.block[0]);

If the device returns any block length above 5, the call overflows
the caller's 5-byte stack buffer before the post-call

	if (ret != 4)
		return -EIO;

check has a chance to reject the response.

Widen the local buffer to I2C_SMBUS_BLOCK_MAX so the helper has room
for any well-formed SMBus block response, matching the convention used
by the other i2c_smbus_read_block_data() callers in this driver.

Fixes: 15609d18 ("hwmon: (pmbus/adm1266) read blackbox")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarAbdurrahman Hussain <abdurrahman@nexthop.ai>
Link: https://lore.kernel.org/r/20260515-adm1266-fixes-v1-2-1c1ea1349cfe@nexthop.ai


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent b86095e3

drivers/hwmon/pmbus/adm1266.c

+1 −1
Original line number Diff line number Diff line
@@ -349,7 +349,7 @@ static int adm1266_nvmem_read_blackbox(struct adm1266_data *data, u8 *read_buff) 
{

	int record_count;

	char index;

	u8 buf[5];

	u8 buf[I2C_SMBUS_BLOCK_MAX];

	int ret;



	ret = i2c_smbus_read_block_data(data->client, ADM1266_BLACKBOX_INFO, buf);