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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 33016C00143 for ; Wed, 1 Sep 2021 12:31:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DF2A610A1 for ; Wed, 1 Sep 2021 12:31:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244971AbhIAMcF (ORCPT ); Wed, 1 Sep 2021 08:32:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:33016 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244761AbhIAMbZ (ORCPT ); Wed, 1 Sep 2021 08:31:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EA196610A1; Wed, 1 Sep 2021 12:30:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1630499428; bh=iFG2hhXMkqgI+AgC85Z5sKXg1Dvw7eyDMrwI/JpE+Gs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wpMZL80j81ouTK4BViYM9Gy8jwO2nEYE2gzh0B1cErCq/AaR9xBC8NzZRaeJiKrc2 XM6hzxOuLdKxU2XiT5/ZHUYxEKMbCeJLfOuq00YFMG95ORB55yCiMawIQiZy6e6bAh vyJOE/3huuhOtNJlJ+mBCJx0bEh+QOI6SVy5y+no= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, George Kennedy , syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com, Dan Carpenter , Dhaval Giani , Bartlomiej Zolnierkiewicz Subject: [PATCH 4.19 30/33] fbmem: add margin check to fb_check_caps() Date: Wed, 1 Sep 2021 14:28:19 +0200 Message-Id: <20210901122251.776826620@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210901122250.752620302@linuxfoundation.org> References: <20210901122250.752620302@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: George Kennedy commit a49145acfb975d921464b84fe00279f99827d816 upstream. A fb_ioctl() FBIOPUT_VSCREENINFO call with invalid xres setting or yres setting in struct fb_var_screeninfo will result in a KASAN: vmalloc-out-of-bounds failure in bitfill_aligned() as the margins are being cleared. The margins are cleared in chunks and if the xres setting or yres setting is a value of zero upto the chunk size, the failure will occur. Add a margin check to validate xres and yres settings. Signed-off-by: George Kennedy Reported-by: syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com Reviewed-by: Dan Carpenter Cc: Dhaval Giani Signed-off-by: Bartlomiej Zolnierkiewicz Link: https://patchwork.freedesktop.org/patch/msgid/1594149963-13801-1-git-send-email-george.kennedy@oracle.com Signed-off-by: Greg Kroah-Hartman --- drivers/video/fbdev/core/fbmem.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -991,6 +991,10 @@ fb_set_var(struct fb_info *info, struct goto done; } + /* bitfill_aligned() assumes that it's at least 8x8 */ + if (var->xres < 8 || var->yres < 8) + return -EINVAL; + ret = info->fbops->fb_check_var(var, info); if (ret)