From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org by pdx-caf-mail.web.codeaurora.org (Dovecot) with LMTP id klh8N0ZZGVu3BwAAmS7hNA ; Thu, 07 Jun 2018 16:11:56 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 1D17860115; Thu, 7 Jun 2018 16:11:55 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by smtp.codeaurora.org (Postfix) with ESMTP id 7F85C6063F; Thu, 7 Jun 2018 16:11:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 7F85C6063F Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935618AbeFGQKo (ORCPT + 25 others); Thu, 7 Jun 2018 12:10:44 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:39195 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932984AbeFGOJB (ORCPT ); Thu, 7 Jun 2018 10:09:01 -0400 Received: from [148.252.241.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1fQvb1-0005Zt-Dc; Thu, 07 Jun 2018 15:08:59 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1fQvax-0002hr-PL; Thu, 07 Jun 2018 15:08:55 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Peter Malone" , "Mathieu Malaterre" , "Bartlomiej Zolnierkiewicz" Date: Thu, 07 Jun 2018 15:05:21 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 023/410] fbdev: Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in sbusfb_ioctl_helper(). In-Reply-To: X-SA-Exim-Connect-IP: 148.252.241.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.57-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Peter Malone commit 250c6c49e3b68756b14983c076183568636e2bde upstream. Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in sbusfb_ioctl_helper(). 'index' is defined as an int in sbusfb_ioctl_helper(). We retrieve this from the user: if (get_user(index, &c->index) || __get_user(count, &c->count) || __get_user(ured, &c->red) || __get_user(ugreen, &c->green) || __get_user(ublue, &c->blue)) return -EFAULT; and then we use 'index' in the following way: red = cmap->red[index + i] >> 8; green = cmap->green[index + i] >> 8; blue = cmap->blue[index + i] >> 8; This is a classic information leak vulnerability. 'index' should be an unsigned int, given its usage above. This patch is straight-forward; it changes 'index' to unsigned int in two switch-cases: FBIOGETCMAP_SPARC && FBIOPUTCMAP_SPARC. This patch fixes CVE-2018-6412. Signed-off-by: Peter Malone Acked-by: Mathieu Malaterre Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Ben Hutchings --- drivers/video/fbdev/sbuslib.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/video/fbdev/sbuslib.c +++ b/drivers/video/fbdev/sbuslib.c @@ -121,7 +121,7 @@ int sbusfb_ioctl_helper(unsigned long cm unsigned char __user *ured; unsigned char __user *ugreen; unsigned char __user *ublue; - int index, count, i; + unsigned int index, count, i; if (get_user(index, &c->index) || __get_user(count, &c->count) || @@ -160,7 +160,7 @@ int sbusfb_ioctl_helper(unsigned long cm unsigned char __user *ugreen; unsigned char __user *ublue; struct fb_cmap *cmap = &info->cmap; - int index, count, i; + unsigned int index, count, i; u8 red, green, blue; if (get_user(index, &c->index) ||