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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 656E1C433FF for ; Tue, 30 Jul 2019 02:32:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3607520693 for ; Tue, 30 Jul 2019 02:32:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="m0a1l+F+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731277AbfG3CcT (ORCPT ); Mon, 29 Jul 2019 22:32:19 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:45393 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729370AbfG3CcS (ORCPT ); Mon, 29 Jul 2019 22:32:18 -0400 Received: by mail-pg1-f195.google.com with SMTP id o13so29196935pgp.12; Mon, 29 Jul 2019 19:32:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=YV/+iCS4EeSNAMRIOjIIW+INsj2i8EpPe81QUMDSEVs=; b=m0a1l+F+LVO7Qb/hH9dKdcZfBbYrqyWJpSE3O4a6VhZERbnGovGqSJ+PI1OaqLuga/ 6gHT2yYrjsfdiVWXtBE8tb+cNJPUgZi3j8wFDvkO/Y/AfG/NUxSppeEEFzUDrrs8O3yd uhrIaAgThHdBTWpTWxkfebhsjhaM9HSzdPqTPlY1eFuQUz7/GMusGTao000YYocoAV4n 63zrD5eV8H4DI2HGx5yTUwBZw5bxsmKqJYYGju3nx4KPVV2TmhhVu3HnUNLVLqVfe2zv JCOMMttOjkv+zV4eXJF70uvcSohEb9ouQZ3o1IksE4HnCmO4/iYPTAI+vPpmMwIvYaLu 2HBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=YV/+iCS4EeSNAMRIOjIIW+INsj2i8EpPe81QUMDSEVs=; b=f+yV3VYT9MXpXddoSjc60lq9VG56IlcWq8zBbQotgHIzmgtNW0OuI+g38q63F494w7 AnGHYRbYDE76O4jjmVcyFtAxiTlerCsQisJYglt4yBmT2vhAGfzDn8gRcctEsjMh9tl2 FrwO8KelWCWt2Gfb46/wxSpVsc/DfMqzdl6GGQrEHoYVpUlnlq1MQ7KHLt3ANM7SXH4U GPbwg0NTzCOTbjfeuzi39y6BYseQx4P8zJGFtfQFEm2N1mnySjB66gvqEv9xGAoXUivA XYWh7rlaFu5lBxyezicjLIZ4qBns77GX18/RY9nNK64gePHWxW46JfeNs4QRLgOdVU5y BkBw== X-Gm-Message-State: APjAAAX+dLyXeVHyChbojEFjM+dCVq2l7Ct9GfaFn9q33GXwR0D42mAL FqXpVBIPAGwtHDg8licISLS9wx2OVGA= X-Google-Smtp-Source: APXvYqxrRdSbPTKzt4ly+c7dnzUq640ClO3tO2ssYDjVziJsbu2BmD86x8kgJ96v+75QQxPN6EIqig== X-Received: by 2002:a62:ac1a:: with SMTP id v26mr40341590pfe.184.1564453938159; Mon, 29 Jul 2019 19:32:18 -0700 (PDT) Received: from oslab.tsinghua.edu.cn ([2402:f000:4:72:808::3ca]) by smtp.gmail.com with ESMTPSA id q24sm56689312pjp.14.2019.07.29.19.32.16 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 29 Jul 2019 19:32:17 -0700 (PDT) From: Jia-Ju Bai To: darrick.wong@oracle.com, bfoster@redhat.com, sandeen@sandeen.net Cc: linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH v2] fs: xfs: Fix possible null-pointer dereferences in xchk_da_btree_block_check_sibling() Date: Tue, 30 Jul 2019 10:32:06 +0800 Message-Id: <20190730023206.14587-1-baijiaju1990@gmail.com> X-Mailer: git-send-email 2.17.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In xchk_da_btree_block_check_sibling(), there is an if statement on line 274 to check whether ds->state->altpath.blk[level].bp is NULL: if (ds->state->altpath.blk[level].bp) When ds->state->altpath.blk[level].bp is NULL, it is used on line 281: xfs_trans_brelse(..., ds->state->altpath.blk[level].bp); struct xfs_buf_log_item *bip = bp->b_log_item; ASSERT(bp->b_transp == tp); Thus, possible null-pointer dereferences may occur. To fix these bugs, ds->state->altpath.blk[level].bp is checked before being used. These bugs are found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai --- v2: * Adjust the code and add an assignment. Thank Darrick J. Wong for helpful advice. --- fs/xfs/scrub/dabtree.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/xfs/scrub/dabtree.c b/fs/xfs/scrub/dabtree.c index 94c4f1de1922..77ff9f97bcda 100644 --- a/fs/xfs/scrub/dabtree.c +++ b/fs/xfs/scrub/dabtree.c @@ -278,7 +278,11 @@ xchk_da_btree_block_check_sibling( /* Compare upper level pointer to sibling pointer. */ if (ds->state->altpath.blk[level].blkno != sibling) xchk_da_set_corrupt(ds, level); - xfs_trans_brelse(ds->dargs.trans, ds->state->altpath.blk[level].bp); + if (ds->state->altpath.blk[level].bp) { + xfs_trans_brelse(ds->dargs.trans, + ds->state->altpath.blk[level].bp); + ds->state->altpath.blk[level].bp = NULL; + } out: return error; } -- 2.17.0