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From:   Tzung-Bi Shih <tzungbi@kernel.org>
To:     bleung@chromium.org, groeck@chromium.org
Cc:     chrome-platform@lists.linux.dev, tzungbi@kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v3 20/23] platform/chrome: cros_ec_proto: handle empty payload in getting cmd mask
Date:   Wed,  8 Jun 2022 11:07:31 +0000
Message-Id: <20220608110734.2928245-21-tzungbi@kernel.org>
In-Reply-To: <20220608110734.2928245-1-tzungbi@kernel.org>
References: <20220608110734.2928245-1-tzungbi@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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cros_ec_get_host_command_version_mask() expects to receive
sizeof(struct ec_response_get_cmd_versions) from send_command().  The
payload is valid only if the return value is positive.

Return -EPROTO if send_command() returns 0 in
cros_ec_get_host_command_version_mask().

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
No v2.  New and separated from the original series.

 drivers/platform/chrome/cros_ec_proto.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 6a5771361383..9e95f9e4b2f8 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -458,6 +458,11 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
 		goto exit;
 	}
 
+	if (ret == 0) {
+		ret = -EPROTO;
+		goto exit;
+	}
+
 	rver = (struct ec_response_get_cmd_versions *)msg->data;
 	*mask = rver->version_mask;
 	ret = 0;
-- 
2.36.1.255.ge46751e96f-goog