From a69b677e47a80319ce148d61cc29a2b57006e78d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?C=C3=A1ssio=20Gabriel?= Date: Tue, 19 May 2026 11:46:19 -0300 Subject: [PATCH] ALSA: scarlett2: Allow flash writes ending at segment boundary MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: 1abfbd3c9527 ("ALSA: scarlett2: Add support for uploading new firmware") Cc: stable@vger.kernel.org Signed-off-by: Cássio Gabriel Link: https://patch.msgid.link/20260519-alsa-scarlett2-flash-write-boundary-v1-1-b550480e92da@gmail.com Signed-off-by: Takashi Iwai --- sound/usb/mixer_scarlett2.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/sound/usb/mixer_scarlett2.c b/sound/usb/mixer_scarlett2.c index 0f83f8981213..8e80a7165faf 100644 --- a/sound/usb/mixer_scarlett2.c +++ b/sound/usb/mixer_scarlett2.c @@ -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;