From patchwork Wed Sep 16 17:53:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thadeu Lima de Souza Cascardo X-Patchwork-Id: 1365756 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4BsJzW2786z9sTW; Thu, 17 Sep 2020 11:19:51 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1kIbdS-0003dT-2e; Wed, 16 Sep 2020 17:54:26 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kIbdP-0003dJ-Ph for kernel-team@lists.ubuntu.com; Wed, 16 Sep 2020 17:54:23 +0000 Received: from 1.general.cascardo.us.vpn ([10.172.70.58] helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kIbdP-000220-41 for kernel-team@lists.ubuntu.com; Wed, 16 Sep 2020 17:54:23 +0000 From: Thadeu Lima de Souza Cascardo To: kernel-team@lists.ubuntu.com Subject: [SRU oem-5.6] xfs: add agf freeblocks verify in xfs_agf_verify Date: Wed, 16 Sep 2020 14:53:45 -0300 Message-Id: <20200916175345.392534-1-cascardo@canonical.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Zheng Bin We recently used fuzz(hydra) to test XFS and automatically generate tmp.img(XFS v5 format, but some metadata is wrong) xfs_repair information(just one AG): agf_freeblks 0, counted 3224 in ag 0 agf_longest 536874136, counted 3224 in ag 0 sb_fdblocks 613, counted 3228 Test as follows: mount tmp.img tmpdir cp file1M tmpdir sync In 4.19-stable, sync will stuck, the reason is: xfs_mountfs xfs_check_summary_counts if ((!xfs_sb_version_haslazysbcount(&mp->m_sb) || XFS_LAST_UNMOUNT_WAS_CLEAN(mp)) && !xfs_fs_has_sickness(mp, XFS_SICK_FS_COUNTERS)) return 0; -->just return, incore sb_fdblocks still be 613 xfs_initialize_perag_data cp file1M tmpdir -->ok(write file to pagecache) sync -->stuck(write pagecache to disk) xfs_map_blocks xfs_iomap_write_allocate while (count_fsb != 0) { nimaps = 0; while (nimaps == 0) { --> endless loop nimaps = 1; xfs_bmapi_write(..., &nimaps) --> nimaps becomes 0 again xfs_bmapi_write xfs_bmap_alloc xfs_bmap_btalloc xfs_alloc_vextent xfs_alloc_fix_freelist xfs_alloc_space_available -->fail(agf_freeblks is 0) In linux-next, sync not stuck, cause commit c2b3164320b5 ("xfs: use the latest extent at writeback delalloc conversion time") remove the above while, dmesg is as follows: [ 55.250114] XFS (loop0): page discard on page ffffea0008bc7380, inode 0x1b0c, offset 0. Users do not know why this page is discard, the better soultion is: 1. Like xfs_repair, make sure sb_fdblocks is equal to counted (xfs_initialize_perag_data did this, who is not called at this mount) 2. Add agf verify, if fail, will tell users to repair This patch use the second soultion. Signed-off-by: Zheng Bin Signed-off-by: Ren Xudong Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong (cherry picked from commit d0c7feaf87678371c2c09b3709400be416b2dc62) CVE-2020-12655 Signed-off-by: Thadeu Lima de Souza Cascardo Acked-by: Stefan Bader Signed-off-by: Thadeu Lima de Souza Cascardo Acked-by: Colin Ian King --- fs/xfs/libxfs/xfs_alloc.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 5a130409f173..0ebf4098a156 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -2858,6 +2858,13 @@ xfs_agf_verify( be32_to_cpu(agf->agf_flcount) <= xfs_agfl_size(mp))) return __this_address; + if (be32_to_cpu(agf->agf_length) > mp->m_sb.sb_dblocks) + return __this_address; + + if (be32_to_cpu(agf->agf_freeblks) < be32_to_cpu(agf->agf_longest) || + be32_to_cpu(agf->agf_freeblks) > be32_to_cpu(agf->agf_length)) + return __this_address; + if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) < 1 || be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) < 1 || be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) > XFS_BTREE_MAXLEVELS || @@ -2869,6 +2876,10 @@ xfs_agf_verify( be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) > XFS_BTREE_MAXLEVELS)) return __this_address; + if (xfs_sb_version_hasrmapbt(&mp->m_sb) && + be32_to_cpu(agf->agf_rmap_blocks) > be32_to_cpu(agf->agf_length)) + return __this_address; + /* * during growfs operations, the perag is not fully initialised, * so we can't use it for any useful checking. growfs ensures we can't @@ -2882,6 +2893,11 @@ xfs_agf_verify( be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length)) return __this_address; + if (xfs_sb_version_hasreflink(&mp->m_sb) && + be32_to_cpu(agf->agf_refcount_blocks) > + be32_to_cpu(agf->agf_length)) + return __this_address; + if (xfs_sb_version_hasreflink(&mp->m_sb) && (be32_to_cpu(agf->agf_refcount_level) < 1 || be32_to_cpu(agf->agf_refcount_level) > XFS_BTREE_MAXLEVELS))