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Date: Fri, 22 Mar 2024 11:46:57 +0200
From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
To: Grigory Bazilevich <bazilevich@sicamp.ru>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Xin Ji <xji@analogixsemi.com>, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org, lvc-project@linuxtesting.org
Subject: Re: [PATCH] usb: typec: anx7411: Fix possible buffer overflow in
 anx7411_send_msg()
Message-ID: <Zf1TkQVipUYhstRZ@kuha.fi.intel.com>
References: <20240316203354.81591-1-bazilevich@sicamp.ru>
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In-Reply-To: <20240316203354.81591-1-bazilevich@sicamp.ru>

On Sat, Mar 16, 2024 at 11:33:53PM +0300, Grigory Bazilevich wrote:
> 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>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  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

-- 
heikki