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From: Grigory Bazilevich <bazilevich@sicamp.ru>
To: Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Xin Ji <xji@analogixsemi.com>
Cc: Grigory Bazilevich <bazilevich@sicamp.ru>,
	linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	lvc-project@linuxtesting.org
Subject: [PATCH] usb: typec: anx7411: Fix possible buffer overflow in anx7411_send_msg()
Date: Sat, 16 Mar 2024 23:33:53 +0300
Message-ID: <20240316203354.81591-1-bazilevich@sicamp.ru>
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Sender: mrfoxygmfr@sicamp.ru

Passing a size argument greater than or equal to MAX_BUF_LEN causes
a buffer overflow when the checksum is written.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: fe6d8a9c8e64 ("usb: typec: anx7411: Add Analogix PD ANX7411 support")
Signed-off-by: Grigory Bazilevich <bazilevich@sicamp.ru>
---
 drivers/usb/typec/anx7411.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/typec/anx7411.c b/drivers/usb/typec/anx7411.c
index b12a07edc71b..70ba56dfb22b 100644
--- a/drivers/usb/typec/anx7411.c
+++ b/drivers/usb/typec/anx7411.c
@@ -733,7 +733,7 @@ static int anx7411_send_msg(struct anx7411_data *ctx, u8 type, u8 *buf, u8 size)
 	u8 crc;
 	int ret;
 
-	size = min_t(u8, size, (u8)MAX_BUF_LEN);
+	size = min_t(u8, size, (u8)(MAX_BUF_LEN - 1));
 	memcpy(msg->buf, buf, size);
 	msg->msg_type = type;
 	/* msg len equals buffer length + msg_type */
-- 
2.39.2