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=-7.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 B3BEAC04EB8 for ; Tue, 4 Dec 2018 11:26:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 79D3A2146D for ; Tue, 4 Dec 2018 11:26:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="hu7K84Hd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 79D3A2146D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726831AbeLDK7t (ORCPT ); Tue, 4 Dec 2018 05:59:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:44760 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727185AbeLDK7p (ORCPT ); Tue, 4 Dec 2018 05:59:45 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0D4C52087F; Tue, 4 Dec 2018 10:59:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1543921184; bh=FZlZSpNN0GhV+Cpypco6qSxAsNMs0ut3aXXbZjATTws=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hu7K84HdYlCvV2LwUFTfbl0+wYFaNHh2Erd+rNK2RhBuWGna8C/1tK6WaO4jNb+6E nIwbzQ+Jl5v+XQZlyOMvwrDhyZ35qVputmDDnxxMfjMCFYsdx7QyRJ5Rq8V4gbSK7P UDFWSi4c5mmYshKSerK+de+SmV6NWGuWCcw0KmNY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Qu Wenruo , Pan Bian , David Sterba Subject: [PATCH 4.19 078/139] btrfs: relocation: set trans to be NULL after ending transaction Date: Tue, 4 Dec 2018 11:49:19 +0100 Message-Id: <20181204103653.365230294@linuxfoundation.org> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181204103649.950154335@linuxfoundation.org> References: <20181204103649.950154335@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pan Bian commit 42a657f57628402c73237547f0134e083e2f6764 upstream. The function relocate_block_group calls btrfs_end_transaction to release trans when update_backref_cache returns 1, and then continues the loop body. If btrfs_block_rsv_refill fails this time, it will jump out the loop and the freed trans will be accessed. This may result in a use-after-free bug. The patch assigns NULL to trans after trans is released so that it will not be accessed. Fixes: 0647bf564f1 ("Btrfs: improve forever loop when doing balance relocation") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo Signed-off-by: Pan Bian Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/relocation.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -3963,6 +3963,7 @@ static noinline_for_stack int relocate_b restart: if (update_backref_cache(trans, &rc->backref_cache)) { btrfs_end_transaction(trans); + trans = NULL; continue; }