From eff53e09e1871e92105aa7c04136680422f02c34 Mon Sep 17 00:00:00 2001
From: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Date: Sun, 24 Apr 2022 19:24:28 +0900
Subject: [PATCH] ALSA: fireworks: fix wrong return count shorter than expected
by 4 bytes
commit eb9d84b0ffe39893cb23b0b6712bbe3637fa25fa upstream.
ALSA fireworks driver has a bug in its initial state to return count
shorter than expected by 4 bytes to userspace applications when handling
response frame for Echo Audio Fireworks transaction. It's due to missing
addition of the size for the type of event in ALSA firewire stack.
Fixes: 555e8a8f7f14 ("ALSA: fireworks: Add command/response functionality into hwdep interface")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20220424102428.21109-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
sound/firewire/fireworks/fireworks_hwdep.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/sound/firewire/fireworks/fireworks_hwdep.c b/sound/firewire/fireworks/fireworks_hwdep.c
index 2e1d9a23920c..09ba61f60699 100644
--- a/sound/firewire/fireworks/fireworks_hwdep.c
+++ b/sound/firewire/fireworks/fireworks_hwdep.c
@@ -35,6 +35,7 @@ hwdep_read_resp_buf(struct snd_efw *efw, char __user *buf, long remained,
type = SNDRV_FIREWIRE_EVENT_EFW_RESPONSE;
if (copy_to_user(buf, &type, sizeof(type)))
return -EFAULT;
+ count += sizeof(type);
remained -= sizeof(type);
buf += sizeof(type);