From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9B45831F983; Sun, 7 Jun 2026 10:24:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780827842; cv=none; b=CBbHmBW/j6Ho6N1OvzmQDfqxqc/KrSqtf42lxCWebP2GD8gZMgFFciI8zRw2GL6GBZgJSyKNFOdgX0MIu9vYFiFO5woGKCRMwdkwegQxAkXVg/MSOKXRZT6xvKVipYfWkinZdjvRqwk4mXoj9kRSjWpHjTlqmTD/wBJFQPZt8WI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780827842; c=relaxed/simple; bh=7AkqWxJzn5d81XkIc7gAgJVT5neUZlr9XxJNqlsZs/A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YBb0OFMOlD39Y/hZtqlIqKpojGih2Wl5cJFjpITGgSM0r8ICD2zR71a4Nxuhlnd3LF3aPsld7t5uRVP9tHHC6pjH2tIw9N0xR42KW8qgU4irjMxJk0E5u2Y8NjTLg70rG1+wpU70ABVBxPH5AKQ6Dkuq8ewlSQQBzQmgB6xhJks= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JEoAPS3d; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JEoAPS3d" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44BA41F00893; Sun, 7 Jun 2026 10:24:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780827841; bh=5zWBmyj67lcIzfjwe9m7dsNOxH4dvYwLt9PB93z9T68=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=JEoAPS3dqfT/a12tNHN7E/kw87Su5L6DiisbRGwH5BOAJLHK6dQlE8TgEa9KsqC1h J1jzDq3lzQpGhEJ5DSCLOsi2+/HQbXXHiBqgdQz7khM00pvjBUVjyywWrhThWO22Fn OiR8/gxHf/wiKSfr1gdWDvvf7WJjXhuejj+FzMVE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Heikki Krogerus Subject: [PATCH 7.0 126/332] usb: typec: wcove: dont write past struct pd_message in wcove_read_rx_buffer() Date: Sun, 7 Jun 2026 11:58:15 +0200 Message-ID: <20260607095732.737538259@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260607095728.031258202@linuxfoundation.org> References: <20260607095728.031258202@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Greg Kroah-Hartman commit 4af7ad0e6d7aa4403dbb1dac7b9659b0421efcaa upstream. wcove_read_rx_buffer() copies the PD RX FIFO into the caller's struct pd_message with for (i = 0; i < USBC_RXINFO_RXBYTES(info); i++) regmap_read(wcove->regmap, USBC_RX_DATA + i, msg + i); which has two problems: USBC_RXINFO_RXBYTES() is a 5-bit field (max 31) while struct pd_message is 30 bytes (__le16 header + __le32 payload[PD_MAX_PAYLOAD], packed). The byte count latched in RXINFO is the number of bytes the port partner put on the wire, so a malicious partner that transmits a 31-byte frame can drive the loop one byte past the destination if the WCOVE BMC receiver does not enforce the PD object-count limit in hardware. The existing FIXME flagged this as unverified. Independently, regmap_read() takes an unsigned int * and stores a full unsigned int at the destination. Passing the byte pointer msg + i means each iteration writes four bytes; the high three are zero (val_bits is 8) and are normally overwritten by the next iteration, but the final iteration's high bytes are not. With RXBYTES == 30 the i == 29 iteration already writes three zero bytes past msg, which sits on the IRQ thread's stack in wcove_typec_irq(). Clamp the loop to sizeof(struct pd_message) and read each register into a local before storing only its low byte, so the copy can never exceed the destination regardless of what RXINFO reports. Assisted-by: gkh_clanker_t1000 Cc: stable Reviewed-by: Heikki Krogerus Link: https://patch.msgid.link/2026051347-clustered-deflected-9543@gregkh Signed-off-by: Greg Kroah-Hartman --- drivers/usb/typec/tcpm/wcove.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) --- a/drivers/usb/typec/tcpm/wcove.c +++ b/drivers/usb/typec/tcpm/wcove.c @@ -444,9 +444,11 @@ static int wcove_start_toggling(struct t return regmap_write(wcove->regmap, USBC_CONTROL1, usbc_ctrl); } -static int wcove_read_rx_buffer(struct wcove_typec *wcove, void *msg) +static int wcove_read_rx_buffer(struct wcove_typec *wcove, + struct pd_message *msg) { - unsigned int info; + unsigned int info, val, len; + u8 *buf = (u8 *)msg; int ret; int i; @@ -454,12 +456,13 @@ static int wcove_read_rx_buffer(struct w if (ret) return ret; - /* FIXME: Check that USBC_RXINFO_RXBYTES(info) matches the header */ + len = min(USBC_RXINFO_RXBYTES(info), sizeof(*msg)); - for (i = 0; i < USBC_RXINFO_RXBYTES(info); i++) { - ret = regmap_read(wcove->regmap, USBC_RX_DATA + i, msg + i); + for (i = 0; i < len; i++) { + ret = regmap_read(wcove->regmap, USBC_RX_DATA + i, &val); if (ret) return ret; + buf[i] = val; } return regmap_write(wcove->regmap, USBC_RXSTATUS,