Commit a69b677e authored by Cássio Gabriel's avatar Cássio Gabriel Committed by Takashi Iwai
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ALSA: scarlett2: Allow flash writes ending at segment boundary 



scarlett2_hwdep_write() rejects writes when offset + count is greater than
or equal to the selected flash segment size. That incorrectly treats a
write ending exactly at the end of the segment as out of space, although
the last byte written is still within the segment.

Split invalid argument checks from the segment-space check, keep
zero-length writes as no-ops, and compare count against the remaining
segment size. This permits exact-end writes and avoids relying on
offset + count before deciding whether the request is in bounds.

Fixes: 1abfbd3c ("ALSA: scarlett2: Add support for uploading new firmware")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarCássio Gabriel <cassiogabrielcontato@gmail.com>
Link: https://patch.msgid.link/20260519-alsa-scarlett2-flash-write-boundary-v1-1-b550480e92da@gmail.com


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 12b1b4f5

sound/usb/mixer_scarlett2.c

+5 −2
Original line number Diff line number Diff line
@@ -9187,12 +9187,15 @@ static long scarlett2_hwdep_write(struct snd_hwdep *hw, 
	flash_size = private->flash_segment_blocks[segment_id] *

		     SCARLETT2_FLASH_BLOCK_SIZE;



	if (count < 0 || *offset < 0 || *offset + count >= flash_size)

		return -ENOSPC;

	if (count < 0 || *offset < 0)

		return -EINVAL;



	if (!count)

		return 0;



	if (*offset >= flash_size || count > flash_size - *offset)

		return -ENOSPC;



	/* Limit the *req size to SCARLETT2_FLASH_RW_MAX */

	if (count > max_data_size)

		count = max_data_size;