From nobody Tue Dec 16 16:37:12 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE442C28B2B for ; Fri, 19 Aug 2022 16:27:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352753AbiHSQ1P (ORCPT ); Fri, 19 Aug 2022 12:27:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42328 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352555AbiHSQXT (ORCPT ); Fri, 19 Aug 2022 12:23:19 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C8BBCD539; Fri, 19 Aug 2022 09:02:57 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B69C1B82819; Fri, 19 Aug 2022 16:02:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D5DFC433D6; Fri, 19 Aug 2022 16:02:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660924974; bh=AcJrX1xUykEM0PUZFgTpse9dGF07x7CuOQftmr59ePw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mBRCC2semryP2zuKSI0n7yxj0xrALrlQedcR2g6QwxHGG5kXQgbvwUUN4ckoqGfAJ Z4zOwHePnaoYx8K8Yi9h6hXzr1hwdywXOMuYEbGcCHWqMR7rLzXrbP3+MtyNGvV3a6 drhzfA38VqYU8DSuojY0G1aHsBqcipv5LcYhATJ4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Harshit Mogalapalli , Jiri Kosina , Sasha Levin Subject: [PATCH 5.10 341/545] HID: mcp2221: prevent a buffer overflow in mcp_smbus_write() Date: Fri, 19 Aug 2022 17:41:51 +0200 Message-Id: <20220819153844.658940181@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220819153829.135562864@linuxfoundation.org> References: <20220819153829.135562864@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Harshit Mogalapalli [ Upstream commit 62ac2473553a00229e67bdf3cb023b62cf7f5a9a ] Smatch Warning: drivers/hid/hid-mcp2221.c:388 mcp_smbus_write() error: __memcpy() '&mcp->txbuf[5]' too small (59 vs 255) drivers/hid/hid-mcp2221.c:388 mcp_smbus_write() error: __memcpy() 'buf' too small (34 vs 255) The 'len' variable can take a value between 0-255 as it can come from data->block[0] and it is user data. So add an bound check to prevent a buffer overflow in memcpy(). Fixes: 67a95c21463d ("HID: mcp2221: add usb to i2c-smbus host bridge") Signed-off-by: Harshit Mogalapalli Signed-off-by: Jiri Kosina Signed-off-by: Sasha Levin --- drivers/hid/hid-mcp2221.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c index 4211b9839209..de52e9f7bb8c 100644 --- a/drivers/hid/hid-mcp2221.c +++ b/drivers/hid/hid-mcp2221.c @@ -385,6 +385,9 @@ static int mcp_smbus_write(struct mcp2221 *mcp, u16 add= r, data_len =3D 7; break; default: + if (len > I2C_SMBUS_BLOCK_MAX) + return -EINVAL; + memcpy(&mcp->txbuf[5], buf, len); data_len =3D len + 5; } --=20 2.35.1