Commit 0e211f6a authored by Sanman Pradhan's avatar Sanman Pradhan Committed by Guenter Roeck
Browse files

hwmon: (tps53679) Fix array access with zero-length block read 



i2c_smbus_read_block_data() can return 0, indicating a zero-length
read. When this happens, tps53679_identify_chip() accesses buf[ret - 1]
which is buf[-1], reading one byte before the buffer on the stack.

Fix by changing the check from "ret < 0" to "ret <= 0", treating a
zero-length read as an error (-EIO), which prevents the out-of-bounds
array access.

Also fix a typo in the adjacent comment: "if present" instead of
duplicate "if".

Fixes: 75ca1e58 ("hwmon: (pmbus/tps53679) Add support for TPS53685")
Signed-off-by: default avatarSanman Pradhan <psanman@juniper.net>
Link: https://lore.kernel.org/r/20260329170925.34581-2-sanman.pradhan@hpe.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 7aaa8047

drivers/hwmon/pmbus/tps53679.c

+3 −3
Original line number Diff line number Diff line
@@ -103,10 +103,10 @@ static int tps53679_identify_chip(struct i2c_client *client, 
	}



	ret = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, buf);

	if (ret < 0)

		return ret;

	if (ret <= 0)

		return ret < 0 ? ret : -EIO;



	/* Adjust length if null terminator if present */

	/* Adjust length if null terminator is present */

	buf_len = (buf[ret - 1] != '\x00' ? ret : ret - 1);



	id_len = strlen(id);