linux-kernel - [PATCH AUTOSEL 5.10 16/33] soundwire: cadence: Don't overwrite msg->buf during write commands

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20221013002334.1894749-16-sashal@kernel.org>
Date:   Wed, 12 Oct 2022 20:23:15 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Richard Fitzgerald <rf@...nsource.cirrus.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
        Vinod Koul <vkoul@...nel.org>, Sasha Levin <sashal@...nel.org>,
        yung-chuan.liao@...ux.intel.com, alsa-devel@...a-project.org
Subject: [PATCH AUTOSEL 5.10 16/33] soundwire: cadence: Don't overwrite msg->buf during write commands

From: Richard Fitzgerald <rf@...nsource.cirrus.com>

[ Upstream commit ba05b39d265bdd16913f7684600d9d41e2796745 ]

The buf passed in struct sdw_msg must only be written for a READ,
in that case the RDATA part of the response is the data value of the
register.

For a write command there is no RDATA, and buf should be assumed to
be const and unmodifable. The original caller should not expect its data
buffer to be corrupted by an sdw_nwrite().

Signed-off-by: Richard Fitzgerald <rf@...nsource.cirrus.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
Link: https://lore.kernel.org/r/20220916103505.1562210-1-rf@opensource.cirrus.com
Signed-off-by: Vinod Koul <vkoul@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/soundwire/cadence_master.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index c6d421a4b91b..a3247692ddc0 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -501,9 +501,12 @@ cdns_fill_msg_resp(struct sdw_cdns *cdns,
 		return SDW_CMD_IGNORED;
 	}
 
-	/* fill response */
-	for (i = 0; i < count; i++)
-		msg->buf[i + offset] = FIELD_GET(CDNS_MCP_RESP_RDATA, cdns->response_buf[i]);
+	if (msg->flags == SDW_MSG_FLAG_READ) {
+		/* fill response */
+		for (i = 0; i < count; i++)
+			msg->buf[i + offset] = FIELD_GET(CDNS_MCP_RESP_RDATA,
+							 cdns->response_buf[i]);
+	}
 
 	return SDW_CMD_OK;
 }
-- 
2.35.1