Files
linux-stable-mirror/drivers/input/touchscreen
Dmitry Torokhov e9b62996ba Input: atmel_mxt_ts - fix boundary check in mxt_prepare_cfg_mem
commit baa0210fb6 upstream.

When a configuration file provides an object size that is larger than the
driver's known mxt_obj_size(object), the driver intends to discard the
extra bytes.

The loop iterates using for (i = 0; i < size; i++). Inside the loop, the
condition to skip processing extra bytes is:

    if (i > mxt_obj_size(object))
        continue;

Since i is a 0-based index, the valid indices for the object are 0 through
mxt_obj_size(object) - 1.

When i == mxt_obj_size(object), the condition evaluates to false, and the
code processes the byte instead of discarding it.

This causes the code to calculate byte_offset = reg + i - cfg->start_ofs
and writes the byte there, overwriting exactly one byte of the adjacent
instance or object.

Update the boundary check to skip extra bytes correctly by using >=.

Fixes: 50a77c658b ("Input: atmel_mxt_ts - download device config using firmware loader")
Cc: stable@vger.kernel.org
Assisted-by: Gemini:gemini-3.1-pro
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
Link: https://patch.msgid.link/20260504185448.4055973-1-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-06-19 13:39:20 +02:00
..