Commit 6f5c69f7 authored Jan 16, 2026 by Samasth Norway Ananda Committed by Takashi Iwai Jan 17, 2026

ALSA: scarlett2: Fix buffer overflow in config retrieval



The scarlett2_usb_get_config() function has a logic error in the
endianness conversion code that can cause buffer overflows when
count > 1.

The code checks `if (size == 2)` where `size` is the total buffer size in
bytes, then loops `count` times treating each element as u16 (2 bytes).
This causes the loop to access `count * 2` bytes when the buffer only
has `size` bytes allocated.

Fix by checking the element size (config_item->size) instead of the
total buffer size. This ensures the endianness conversion matches the
actual element type.

Fixes: ac34df73 ("ALSA: usb-audio: scarlett2: Update get_config to do endian conversion")
Cc: stable@vger.kernel.org
Signed-off-by: Samasth Norway Ananda <samasth.norway.ananda@oracle.com>
Link: https://patch.msgid.link/20260117012706.1715574-1-samasth.norway.ananda@oracle.com


Signed-off-by: Takashi Iwai <tiwai@suse.de>

parent 6b971191

sound/usb/mixer_scarlett2.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -2533,13 +2533,13 @@ static int scarlett2_usb_get_config(
		err = scarlett2_usb_get(mixer, config_item->offset, buf, size);
		if (err < 0)
		return err;
		if (size == 2) {
		if (config_item->size == 16) {
		u16 *buf_16 = buf;

		for (i = 0; i < count; i++, buf_16++)
		buf_16 = le16_to_cpu((__le16 *)buf_16);
		} else if (size == 4) {
		u32 *buf_32 = buf;
		} else if (config_item->size == 32) {
		u32 buf_32 = (u32 )buf;

		for (i = 0; i < count; i++, buf_32++)
		buf_32 = le32_to_cpu((__le32 *)buf_32);