In the Linux kernel, the following vulnerability has been resolved: hwmon: adm1275: Prevent...

In the Linux kernel, the following vulnerability has been resolved:

hwmon: adm1275: Prevent reading uninitialized stack

While adding support for the ROHM BD127X0 hot-swap controllers, sashiko reported an error in device-name comparison, which can lead to reading uninitialized stack memory.

Quoting Sashiko:

This is a pre-existing issue, but I noticed that just before this block in adm1275_probe(), there might be an out-of-bounds stack read:

ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, block_buffer);
if (ret < 0) { ... }
for (mid = adm1275_id; mid->name[0]; mid++) {
        if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
                break;
}

Since i2c_smbus_read_block_data() reads up to 32 bytes into the uninitialized stack array block_buffer without appending a null terminator, strncasecmp() could read past the valid bytes returned in ret.

For example, if the device returns a shorter string like "adm12", checking it against "adm1275" up to the length of "adm1275" will continue reading into uninitialized stack bounds.

Prevent reading uninitialized memory by zeroing the stack array.