Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Pin-Yen Lin <treapking@chromium.org>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Robert Foss <robert.foss@linaro.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 454/913] drm/bridge: anx7625: Fix overflow issue on reading EDID
Date:   Tue,  5 Apr 2022 09:25:16 +0200
Message-Id: <20220405070353.457356586@linuxfoundation.org>
In-Reply-To: <20220405070339.801210740@linuxfoundation.org>
References: <20220405070339.801210740@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Pin-Yen Lin <treapking@chromium.org>

[ Upstream commit d5c6f647aec9ed524aedd04a3aec5ebc21d39007 ]

The length of EDID block can be longer than 256 bytes, so we should use
`int` instead of `u8` for the `edid_pos` variable.

Fixes: 8bdfc5dae4e3 ("drm/bridge: anx7625: Add anx7625 MIPI DSI/DPI to DP")
Signed-off-by: Pin-Yen Lin <treapking@chromium.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220210103827.402436-1-treapking@chromium.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/bridge/analogix/anx7625.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index ea414cd349b5..392a9c56e9a0 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -791,7 +791,8 @@ static int segments_edid_read(struct anx7625_data *ctx,
 static int sp_tx_edid_read(struct anx7625_data *ctx,
 			   u8 *pedid_blocks_buf)
 {
-	u8 offset, edid_pos;
+	u8 offset;
+	int edid_pos;
 	int count, blocks_num;
 	u8 pblock_buf[MAX_DPCD_BUFFER_SIZE];
 	u8 i, j;
-- 
2.34.1