From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9AEF7C072B1 for ; Thu, 30 May 2019 04:08:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 71728250C0 for ; Thu, 30 May 2019 04:08:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559189288; bh=B3DhlEJ4ntR8egRJP5RlZfeyVV2zTNXwZoWVRbGKFCE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=iTIqbK1GtUI/gTO7GzpQ2/4UxA6H3UB+MYCzd9cURySvyGuaZxBErN15cYQc5rruD Un3F7OTmDGi1jIGeX3/J1tbFFYejAN+G41nR6V4u28TbMkll/IynzLbyxWAtAAqD8G HNMgdW+VGl/64Dl1oYYLMgei1IX6tQEV/LFjeQYQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731087AbfE3DRX (ORCPT ); Wed, 29 May 2019 23:17:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:46214 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731079AbfE3DRW (ORCPT ); Wed, 29 May 2019 23:17:22 -0400 Received: from localhost (ip67-88-213-2.z213-88-67.customer.algx.net [67.88.213.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D7F702463F; Thu, 30 May 2019 03:17:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559186242; bh=B3DhlEJ4ntR8egRJP5RlZfeyVV2zTNXwZoWVRbGKFCE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yvvINWwa7TkoOxfxqMbQDJoQYKY+wx0nwIwBK8HaIG6MjOBct5meD37BIbvIOlkOr +ud3nDxZHVmj4tCoFyBUMCCKi7Ka91OGZKXUjPNOFhVrmBLVWsqdxaaKQxIGKSez/a 2/Z9+K7u1KGfuz87vRnvAHA8VXqs/IHehDIpwORo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 4.19 128/276] media: pvrusb2: Prevent a buffer overflow Date: Wed, 29 May 2019 20:04:46 -0700 Message-Id: <20190530030533.803120908@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190530030523.133519668@linuxfoundation.org> References: <20190530030523.133519668@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit c1ced46c7b49ad7bc064e68d966e0ad303f917fb ] The ctrl_check_input() function is called from pvr2_ctrl_range_check(). It's supposed to validate user supplied input and return true or false depending on whether the input is valid or not. The problem is that negative shifts or shifts greater than 31 are undefined in C. In practice with GCC they result in shift wrapping so this function returns true for some inputs which are not valid and this could result in a buffer overflow: drivers/media/usb/pvrusb2/pvrusb2-ctrl.c:205 pvr2_ctrl_get_valname() warn: uncapped user index 'names[val]' The cptr->hdw->input_allowed_mask mask is configured in pvr2_hdw_create() and the highest valid bit is BIT(4). Fixes: 7fb20fa38caa ("V4L/DVB (7299): pvrusb2: Improve logic which handles input choice availability") Signed-off-by: Dan Carpenter Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/usb/pvrusb2/pvrusb2-hdw.c | 2 ++ drivers/media/usb/pvrusb2/pvrusb2-hdw.h | 1 + 2 files changed, 3 insertions(+) diff --git a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c index a8519da0020bf..673fdca8d2dac 100644 --- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c +++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c @@ -666,6 +666,8 @@ static int ctrl_get_input(struct pvr2_ctrl *cptr,int *vp) static int ctrl_check_input(struct pvr2_ctrl *cptr,int v) { + if (v < 0 || v > PVR2_CVAL_INPUT_MAX) + return 0; return ((1 << v) & cptr->hdw->input_allowed_mask) != 0; } diff --git a/drivers/media/usb/pvrusb2/pvrusb2-hdw.h b/drivers/media/usb/pvrusb2/pvrusb2-hdw.h index 25648add77e58..bd2b7a67b7322 100644 --- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.h +++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.h @@ -50,6 +50,7 @@ #define PVR2_CVAL_INPUT_COMPOSITE 2 #define PVR2_CVAL_INPUT_SVIDEO 3 #define PVR2_CVAL_INPUT_RADIO 4 +#define PVR2_CVAL_INPUT_MAX PVR2_CVAL_INPUT_RADIO enum pvr2_config { pvr2_config_empty, /* No configuration */ -- 2.20.1