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=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 42EEFC55178 for ; Tue, 27 Oct 2020 00:12:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F153B2087C for ; Tue, 27 Oct 2020 00:12:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603757551; bh=qLvmBJkm7pNipv8UemS7QoIH2Dp3l599ylsEGcnSB8I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eZLSKAAHmeqaBEVY/6lh9qZsd2vdXHfBuCQT6PG/4+HKC3u7q5BxEqpbym1imSYEp 9jjv/YTCBJ96Zb8RMj3ZMRVVkjpyqDCCgxnjDNyGduqyjsQcbV51uPx2O2u/o8hxEp m2BRCA7vLmp21QA7WAO8dl05m+TOXhtGovQHs/AI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439345AbgJ0AM3 (ORCPT ); Mon, 26 Oct 2020 20:12:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:33870 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2411831AbgJ0ALx (ORCPT ); Mon, 26 Oct 2020 20:11:53 -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 59B0020709; Tue, 27 Oct 2020 00:11:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603757512; bh=qLvmBJkm7pNipv8UemS7QoIH2Dp3l599ylsEGcnSB8I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rQ1YKYSeX0omAgaI6HKMRdhxfv6jjxdFGkiEylZbn/EPovao5XZqg1/AsjlGdSuru 9BNCsh6kSEBH7gepLkr8SafVcZOS1vIYq963ZlfVNQuTWTY4/cIOCTcZuEri+Y6aBg 1ZKd3ACU12cx86iK0viOobY6sRLBHR1k7zi5xZi4= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Anant Thazhemadam , syzbot+af90d47a37376844e731@syzkaller.appspotmail.com, Andrew Price , Andreas Gruenbacher , Sasha Levin , cluster-devel@redhat.com Subject: [PATCH AUTOSEL 4.4 22/25] gfs2: add validation checks for size of superblock Date: Mon, 26 Oct 2020 20:11:20 -0400 Message-Id: <20201027001123.1027642-22-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201027001123.1027642-1-sashal@kernel.org> References: <20201027001123.1027642-1-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: Anant Thazhemadam [ Upstream commit 0ddc5154b24c96f20e94d653b0a814438de6032b ] In gfs2_check_sb(), no validation checks are performed with regards to the size of the superblock. syzkaller detected a slab-out-of-bounds bug that was primarily caused because the block size for a superblock was set to zero. A valid size for a superblock is a power of 2 between 512 and PAGE_SIZE. Performing validation checks and ensuring that the size of the superblock is valid fixes this bug. Reported-by: syzbot+af90d47a37376844e731@syzkaller.appspotmail.com Tested-by: syzbot+af90d47a37376844e731@syzkaller.appspotmail.com Suggested-by: Andrew Price Signed-off-by: Anant Thazhemadam [Minor code reordering.] Signed-off-by: Andreas Gruenbacher Signed-off-by: Sasha Levin --- fs/gfs2/ops_fstype.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index b7b43d00cc6d7..8ed2b1a716376 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -160,15 +160,19 @@ static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent) return -EINVAL; } - /* If format numbers match exactly, we're done. */ - - if (sb->sb_fs_format == GFS2_FORMAT_FS && - sb->sb_multihost_format == GFS2_FORMAT_MULTI) - return 0; + if (sb->sb_fs_format != GFS2_FORMAT_FS || + sb->sb_multihost_format != GFS2_FORMAT_MULTI) { + fs_warn(sdp, "Unknown on-disk format, unable to mount\n"); + return -EINVAL; + } - fs_warn(sdp, "Unknown on-disk format, unable to mount\n"); + if (sb->sb_bsize < 512 || sb->sb_bsize > PAGE_SIZE || + (sb->sb_bsize & (sb->sb_bsize - 1))) { + pr_warn("Invalid superblock size\n"); + return -EINVAL; + } - return -EINVAL; + return 0; } static void end_bio_io_page(struct bio *bio) -- 2.25.1