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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 2D4D1C28CC0 for ; Thu, 30 May 2019 04:28:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 06E4625578 for ; Thu, 30 May 2019 04:28:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559190536; bh=o2y8YLycyyCjFf/NQIgXgw4I54SvPPf4QrE6X38uT9k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Ap7SYc+XZWCCSnMDtXV8rnhmi6w6FhjTq5iixu6QjTp/sIvPNpXTrU8E6SVNBioYI 9m7kFFILMBB4wXMPsjFvNO/xdxYq3jKC+LZQ7HRCoBwD1ljUvfmv/91621WirgDM4b qrJqH20lxFb7L1+20eAaLPDOLoJAwbjZieH3VkSs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387962AbfE3E2u (ORCPT ); Thu, 30 May 2019 00:28:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:33326 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729744AbfE3DOK (ORCPT ); Wed, 29 May 2019 23:14:10 -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 BA6592455C; Thu, 30 May 2019 03:14:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559186049; bh=o2y8YLycyyCjFf/NQIgXgw4I54SvPPf4QrE6X38uT9k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=buC8WJYFa5PFIsyjS74rU7iyI+efqwEI8/RmpeH0Dw/ZSrByrh1wgjAeraNr2Es5B ePRNVf12/Ymzu6EYL99U6NuokBTaUEp/un63WyyamajFWJ8vCtCfYXxfoM46RCFpeC up6foreV/3iYWyG07m8zw4sk9Mq/Z+x2u3UxawZw= 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 5.0 145/346] media: pvrusb2: Prevent a buffer overflow Date: Wed, 29 May 2019 20:03:38 -0700 Message-Id: <20190530030548.499326331@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190530030540.363386121@linuxfoundation.org> References: <20190530030540.363386121@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 446a999dd2ce1..2bab4713bc5b9 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