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 A6F3BC3A5A9 for ; Mon, 4 May 2020 15:34:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FD262073B for ; Mon, 4 May 2020 15:34:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="GITI6WzH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729421AbgEDPeh (ORCPT ); Mon, 4 May 2020 11:34:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34010 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726509AbgEDPeh (ORCPT ); Mon, 4 May 2020 11:34:37 -0400 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 39766C061A0E for ; Mon, 4 May 2020 08:34:37 -0700 (PDT) Received: by mail-pg1-x542.google.com with SMTP id q124so8599020pgq.13 for ; Mon, 04 May 2020 08:34:37 -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=MttICuxXavbYMq8WIjicbuvf1Y6ye3X+bWJxx0AAnXc=; b=GITI6WzHQ8sPVvnvNjM/77u08qgAq7eXKr1ZaNlw2etpk+K0D2RIl+nt2Lm77+qcp+ WT2VCckI36iyFh/n8nGxdzrNp1gUGTzjtjJT4tY6Ko36IvJZsAkM/5vnNjvSbVf9LaY7 DUccfi+2/Zf2VjUl8GIMQCaAHtBb1N/u3mL7rD9CgeB9QA7rKNYFhrNzmttYAW1tGQ2c wr9SK36Ap5IDTURoTjocTnJfqz4YlSt8L62ieB+NXzXqGVuPAPdHkPtqcJoJUaiTR5oE +o2yVX7s5M4PUNdc5bqReRhkodBRSfxoVorAVIJUmNEMq75zMns/Panug5Tr+3cxf+Ya FjKQ== 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=MttICuxXavbYMq8WIjicbuvf1Y6ye3X+bWJxx0AAnXc=; b=cA2LxR7FCwC3biK7DhkowLM78SE0Kb85yQZZQggTwvgCKms0B8Exl8dR3ZeMlahp6z a2xxwu6mXAxvIO3WTGF53iuUqDZ6OHJfbU/LHv8aGKN1CzXPYm8LR2r8Exdpn2y6mOdl ryIGwmMPdrsHtYsMK7KtPZeu5eBwe6YOZCBY465DVpTiF9LDoQLv7EzWa3r6ZOsyaozk qlY0IqtWdI7RRcXtHlDQQ+oDElwWbxeFU9uKGwfV/9lAwDGfrvNOxCXXvJxGRpXocK7j lC3KZB3OfOv0ghdpwrmQkkUebp1rigFdcqRMM8qqhK/yiH6RNhcEOZ1sDnMEOCtKxkpS UthQ== X-Gm-Message-State: AGi0PuaNrLGwv3eKUnyebS8avrMHG+Bv1rkB4Xp1wrAR6/b5F66YNuJg mjVZwm4sYnqnJbP2bg2JhBc= X-Google-Smtp-Source: APiQypLtehcfIcerd1n0dU1u3gBN3WpIFPxv0tu5ClUiy1B3odbFiv7d19IM0wiaN9hOXAODfk/zBA== X-Received: by 2002:a65:6713:: with SMTP id u19mr1438519pgf.143.1588606476815; Mon, 04 May 2020 08:34:36 -0700 (PDT) Received: from localhost.localdomain ([120.244.110.63]) by smtp.gmail.com with ESMTPSA id c4sm7178830pga.73.2020.05.04.08.34.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 May 2020 08:34:36 -0700 (PDT) From: Jia-Ju Bai To: shaggy@kernel.org Cc: jfs-discussion@lists.sourceforge.net, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] fs: jfs: fix a possible data race in txBegin() Date: Mon, 4 May 2020 23:34:11 +0800 Message-Id: <20200504153411.13679-1-baijiaju1990@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The functions txBegin() and txLazyCommit() can be concurrently executed in the following call contexts: Thread1: jfs_write_inode() jfs_commit_inode() txBegin() Thread2: jfs_lazycommit() txLazyCommit() In txBegin(): tblk->next = tblk->last = tblk->xflag = tblk->flag = tblk->lsn = 0; In txLazyCommit(): spin_lock_irq(&log->gclock); ... tblk->flag |= tblkGC_COMMITTED; ... spin_unlock_irq(&log->gclock); Thus, a data race can occur for tblk->flag. To fix this data race, the spinlock log->gclock is used in txBegin(). This data race is found by our concurrency fuzzer. Signed-off-by: Jia-Ju Bai --- fs/jfs/jfs_txnmgr.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/jfs/jfs_txnmgr.c b/fs/jfs/jfs_txnmgr.c index c8ce7f1bc594..a1f124aad2e0 100644 --- a/fs/jfs/jfs_txnmgr.c +++ b/fs/jfs/jfs_txnmgr.c @@ -415,7 +415,9 @@ tid_t txBegin(struct super_block *sb, int flag) * * memset(tblk, 0, sizeof(struct tblock)); */ + spin_lock_irq(&log->gclock); tblk->next = tblk->last = tblk->xflag = tblk->flag = tblk->lsn = 0; + spin_unlock_irq(&log->gclock); tblk->sb = sb; ++log->logtid; -- 2.17.1