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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 5C6BFC433E7 for ; Sun, 18 Oct 2020 19:48:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E74F20735 for ; Sun, 18 Oct 2020 19:48:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603050485; bh=gso6STyjOqktB9BpQ65BQqrnebgWWcHpYowKIcR6/BY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=UVZvgJ+6J22XCv0o1R8Thw3TzCGDTuKCP8kItPUXGUEKCZR2JiGi6KEcEdGnYPMmF O9pIEkMLXv/GTtFAhHn5mReqPRjUQz8e8Vib5gnh8Z8AuclwGSg7z6NdFVQwP3qLJc Mq+93LK8T6Zs/ah+O4P7TSrejOhKqc3OQ5cZSoRs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730390AbgJRTsD (ORCPT ); Sun, 18 Oct 2020 15:48:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:34700 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729699AbgJRTWG (ORCPT ); Sun, 18 Oct 2020 15:22:06 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9A7FD22365; Sun, 18 Oct 2020 19:22:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603048925; bh=gso6STyjOqktB9BpQ65BQqrnebgWWcHpYowKIcR6/BY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SQsvClmAG9IM2dxPrkbAd0mxLCp/QU/ybLh+FEIpAT0+qGt0XOkT1Pl3pTgoCFlPc SJpcCKyvMF/2mUp3DsW+gF/7GUAbEMBor4IwSCAxcf8lyu4s7LoLSALZHZ4UHD6i9K NBGYp7F9XzYYRyMSJh1alqqGqY0eotEEQbtrE0dY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: George Kennedy , syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com, Dan Carpenter , Dhaval Giani , Bartlomiej Zolnierkiewicz , Sasha Levin , linux-fbdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.8 082/101] fbmem: add margin check to fb_check_caps() Date: Sun, 18 Oct 2020 15:20:07 -0400 Message-Id: <20201018192026.4053674-82-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201018192026.4053674-1-sashal@kernel.org> References: <20201018192026.4053674-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: George Kennedy [ Upstream commit a49145acfb975d921464b84fe00279f99827d816 ] 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: Sasha Levin --- drivers/video/fbdev/core/fbmem.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index da7c88ffaa6a8..1136b569ccb7c 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1006,6 +1006,10 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var) return 0; } + /* 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) -- 2.25.1