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 0DCF656B853; Wed, 9 Sep 2026 14:38:42 +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=1788964724; cv=none; b=u97wC7JEHKNgwBD3oCB0qiuQHIO/RCrZb4urN4HQCPN0+O7q/0WJVBzo+0DqdARHeKgmYrx+ZtizCyFzGhNvEOPa+XWVHsUvRQxu1hZhDDxBxGuGwBxkabqJDrHmz80YHMNIqNktDwGtIo2+Ne/PxJqAt7fwyHKDWZzMCkC+OsU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788964724; c=relaxed/simple; bh=YDlBocotIJCjoknB4Rdz2/Q7ic2ISVGz4VKfloYBvuo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=PUtUFPD7jsqlo3NLLuVWs7HvTOd2moI8zcZmcxSKdRkkzSTi9hfsro2GcrhUvzC2ODLPdZ6m8Z5/7KpBTGKJsEfrzLLj7Unxtq5JmOhoJ5viz3+gEADEQyqXCNawIyVd39jKYn30xt7/acWDlmL0XwDJUAmr7mESQ2+Sxm68qHI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bLuKNdaS; 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="bLuKNdaS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E0EC1F00A3A; Wed, 9 Sep 2026 14:38:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788964722; bh=lnJW/YyJmh962pE0aS4kntBOb9kGpajDqHdlIN08PDI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bLuKNdaSMS3++rP6wq9RDSOMyRKpZZnSCBdjzWusQwsTAo/LHs2Tt7Sgx7x13oVrC ZynChYb2+j+5bD71oYeYqjZHfgEE6NI53MTMFZJU8A/0LOZoaPh+jCbaYMsJ6mjXgh B8U4mfOVEph6YOvSnMX3GYGxmyhsOqwNsZZFZfQM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Beno=C3=AEt=20Sevens?= , Florian Pradines , Jiri Kosina , Sasha Levin Subject: [PATCH 6.18 473/583] HID: mcp2221: fix OOB write in mcp2221_raw_event() Date: Wed, 9 Sep 2026 15:42:38 +0200 Message-ID: <20260909134254.252733075@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260909134237.773280130@linuxfoundation.org> References: <20260909134237.773280130@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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Pradines [ Upstream commit f097d246677b03db814c5862f368cea341b76a00 ] mcp2221_raw_event() copies device-supplied data into mcp->rxbuf at offset rxbuf_idx without checking that the copy fits within the destination buffer. A device responding with up to 60 bytes to a small I2C/SMBus read can overflow the buffer. Add a rxbuf_size field to struct mcp2221, set it alongside rxbuf in mcp_i2c_smbus_read(), and check rxbuf_idx + data[3] <= rxbuf_size before the memcpy. Reported-by: Benoît Sevens Signed-off-by: Florian Pradines Signed-off-by: Jiri Kosina Stable-dep-of: db2333f88729 ("HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hid-mcp2221.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/hid/hid-mcp2221.c +++ b/drivers/hid/hid-mcp2221.c @@ -121,6 +121,7 @@ struct mcp2221 { u8 *rxbuf; u8 txbuf[64]; int rxbuf_idx; + int rxbuf_size; int status; u8 cur_i2c_clk_div; struct gpio_chip *gc; @@ -323,12 +324,14 @@ static int mcp_i2c_smbus_read(struct mcp mcp->txbuf[3] = (u8)(msg->addr << 1); total_len = msg->len; mcp->rxbuf = msg->buf; + mcp->rxbuf_size = msg->len; } else { mcp->txbuf[1] = smbus_len; mcp->txbuf[2] = 0; mcp->txbuf[3] = (u8)(smbus_addr << 1); total_len = smbus_len; mcp->rxbuf = smbus_buf; + mcp->rxbuf_size = smbus_len; } ret = mcp_send_data_req_status(mcp, mcp->txbuf, 4); @@ -915,6 +918,10 @@ static int mcp2221_raw_event(struct hid_ mcp->status = -EINVAL; break; } + if (mcp->rxbuf_idx + data[3] > mcp->rxbuf_size) { + mcp->status = -EINVAL; + break; + } if (4 + data[3] > size) { mcp->status = -EINVAL; break;