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,URIBL_BLOCKED,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 282E0C04EBF for ; Tue, 4 Dec 2018 11:06:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C032D2146D for ; Tue, 4 Dec 2018 11:06:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="h5gHMmYi" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C032D2146D 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 S1728236AbeLDLF7 (ORCPT ); Tue, 4 Dec 2018 06:05:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:53980 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727918AbeLDLFy (ORCPT ); Tue, 4 Dec 2018 06:05:54 -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 8AD662082D; Tue, 4 Dec 2018 11:05:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1543921554; bh=099MSU3w0YUHTV4nhb96uDIoxiRHqSC6HOyrKWHsAW4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=h5gHMmYieOuIVklWRR+3rM2U95ekoZIIFFoKB5tWLJgliEK+4FQiW+QoRSHp38+F2 0aeAcesuo3HeO6hmpRt+1Y7Udve88BWKlR32P6zgRCv/TNfFp584MU82LKWbBs75AS lBBvvzRVwJ3y2+4MYfAKAL8ejcvlrd8HHFQOFh1g= 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 4.14 117/146] btrfs: relocation: set trans to be NULL after ending transaction Date: Tue, 4 Dec 2018 11:50:03 +0100 Message-Id: <20181204103731.530084930@linuxfoundation.org> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181204103726.750894136@linuxfoundation.org> References: <20181204103726.750894136@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 4.14-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 @@ -4048,6 +4048,7 @@ static noinline_for_stack int relocate_b restart: if (update_backref_cache(trans, &rc->backref_cache)) { btrfs_end_transaction(trans); + trans = NULL; continue; }