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 C2B75C4363A for ; Mon, 26 Oct 2020 23:58:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 81F6420874 for ; Mon, 26 Oct 2020 23:58:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603756737; bh=4Hl0iTqt+SBIwXYGMu3Xu5V0lsutjycnTZ1fMWl+EtM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Y836QlXNAlNXxP0gZM8xS1g6BhoDj1DcfuldzaOaJlvbex1mtx9AeAOEUh7OW3CU3 i6dTu9jrKFX5abrvXpFaNIg903hiVnIPXBKO+V2zwqQ7WDmL6IAcPsRuQrY2QJqXva HekGCKlgEuOE70ViVq0SPcLedP4voVC7SsL1RYzA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437074AbgJZX6i (ORCPT ); Mon, 26 Oct 2020 19:58:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:60456 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2410464AbgJZXyc (ORCPT ); Mon, 26 Oct 2020 19:54:32 -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 DC6BD221F8; Mon, 26 Oct 2020 23:54:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603756470; bh=4Hl0iTqt+SBIwXYGMu3Xu5V0lsutjycnTZ1fMWl+EtM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qLjyruaEQcTvIhQmJB3E5wcvt7RCLGo1UJCiPx5xzQXOMBTWGAmXGY3R/45QlrqW5 NfFbiWL85Swyr5+1DcjSQC6JyjC9uKHMRv4kQSpJAUM0m6Zs38XB9Rek/3Wsind5jR FU/gpKxl3h5nz8SfsnBpBkNfl8vPwtEI1cdJ74Sk= 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 5.8 117/132] gfs2: add validation checks for size of superblock Date: Mon, 26 Oct 2020 19:51:49 -0400 Message-Id: <20201026235205.1023962-117-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201026235205.1023962-1-sashal@kernel.org> References: <20201026235205.1023962-1-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 5bd602a290f72..03c33fc03c055 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -169,15 +169,19 @@ 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