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 E2BE9C072B1 for ; Thu, 30 May 2019 03:45:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B85B324CA7 for ; Thu, 30 May 2019 03:45:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559187904; bh=3TA2AzyxQEl+G5zh5dnkbqdGmZr3VF6U1/rc6Iz8bqU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZAwpyFz5kzLersVUFtawI+TMmh2Qcr8r+q3WDAGFygBL7ur2Ir1WYIFcr1hsAuqnG fUVsiLtUgfp10aQGGl6c+QtMHxWci1DJpKCaA25YX2t0UTjVd6eidTbY4qZ85hyX4U h1UTpI1wLs892k/y1is4pb7cLG7mnfp3Y0JRw/uw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732934AbfE3DpA (ORCPT ); Wed, 29 May 2019 23:45:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:60312 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732367AbfE3DUw (ORCPT ); Wed, 29 May 2019 23:20:52 -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 D6D722492F; Thu, 30 May 2019 03:20:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559186451; bh=3TA2AzyxQEl+G5zh5dnkbqdGmZr3VF6U1/rc6Iz8bqU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ApvSibe03Y8gIqUaggIXgymjULeZpmraAJSWe8q4T2u6UkyPMhKC2W2zgpNwUMcbW qQAusZYe2eE2TODDQqfaKkaYjzjq6NSCjyGD0HMwMj588j4gwK+KWjeDNiit6KOSnV wi3+QaiHQKE/Utfey7OgI3N2qvze3M9LySDInFyU= 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 4.9 063/128] media: pvrusb2: Prevent a buffer overflow Date: Wed, 29 May 2019 20:06:35 -0700 Message-Id: <20190530030446.046747137@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190530030432.977908967@linuxfoundation.org> References: <20190530030432.977908967@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 1eb4f7ba2967d..ff489645e0701 100644 --- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c +++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c @@ -670,6 +670,8 @@ 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 a82a00dd73293..80869990ffbbb 100644 --- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.h +++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.h @@ -54,6 +54,7 @@ #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