From nobody Mon Sep 29 20:10:00 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 042E6C25B0D for ; Tue, 16 Aug 2022 04:45:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231871AbiHPEpR (ORCPT ); Tue, 16 Aug 2022 00:45:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232798AbiHPElj (ORCPT ); Tue, 16 Aug 2022 00:41:39 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2781517ED60; Mon, 15 Aug 2022 13:34:25 -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 dfw.source.kernel.org (Postfix) with ESMTPS id DFEC960EE9; Mon, 15 Aug 2022 20:34:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE559C433C1; Mon, 15 Aug 2022 20:34:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660595663; bh=AcJrX1xUykEM0PUZFgTpse9dGF07x7CuOQftmr59ePw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HnzbR1uczoLughH+2LCILbxULfC6nHivQqaoOtVr58xOEiivlyfHFO2eBBM4bk6Bh tfFS4DECRAnLazM4sX4+f9UbtGFNcnK21gEUt2xHR+FW3DF+hFaNjjo44/5gsQ563V b/TRqs7wZt4/VtXjk2jEYcJJoQlPapHp7YQb2WAo= 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 5.19 0836/1157] HID: mcp2221: prevent a buffer overflow in mcp_smbus_write() Date: Mon, 15 Aug 2022 20:03:12 +0200 Message-Id: <20220815180512.938203773@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180439.416659447@linuxfoundation.org> References: <20220815180439.416659447@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