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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Charles Keepax <ckeepax@opensource.cirrus.com>,
        Mark Brown <broonie@kernel.org>
Subject: [PATCH 5.16 188/227] ASoC: wm_adsp: Correct control read size when parsing compressed buffer
Date:   Mon, 21 Feb 2022 09:50:07 +0100
Message-Id: <20220221084941.068129878@linuxfoundation.org>
In-Reply-To: <20220221084934.836145070@linuxfoundation.org>
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From: Charles Keepax <ckeepax@opensource.cirrus.com>

commit a887f9c7a4d37a8e874ba8415a42a92a1b5139fc upstream.

When parsing the compressed stream the whole buffer descriptor is
now read in a single cs_dsp_coeff_read_ctrl; on older firmwares
this descriptor is just 4 bytes but on more modern firmwares it is
24 bytes. The current code reads the full 24 bytes regardless, this
was working but reading junk for the last 20 bytes. However commit
f444da38ac92 ("firmware: cs_dsp: Add offset to cs_dsp read/write")
added a size check into cs_dsp_coeff_read_ctrl, causing the older
firmwares to now return an error.

Update the code to only read the amount of data appropriate for
the firmware loaded.

Fixes: 04ae08596737 ("ASoC: wm_adsp: Switch to using wm_coeff_read_ctrl for compressed buffers")
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20220210172053.22782-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 sound/soc/codecs/wm_adsp.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -1448,7 +1448,8 @@ static int wm_adsp_buffer_parse_coeff(st
 	int ret, i;
 
 	for (i = 0; i < 5; ++i) {
-		ret = cs_dsp_coeff_read_ctrl(cs_ctl, &coeff_v1, sizeof(coeff_v1));
+		ret = cs_dsp_coeff_read_ctrl(cs_ctl, &coeff_v1,
+					     min(cs_ctl->len, sizeof(coeff_v1)));
 		if (ret < 0)
 			return ret;