From patchwork Sun Sep 17 21:06:39 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 9955233 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 537656028A for ; Sun, 17 Sep 2017 21:08:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 47A53207A7 for ; Sun, 17 Sep 2017 21:08:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3C9E8223C7; Sun, 17 Sep 2017 21:08:24 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 128DB28478 for ; Sun, 17 Sep 2017 21:08:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751576AbdIQVIS (ORCPT ); Sun, 17 Sep 2017 17:08:18 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:39469 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752067AbdIQVHU (ORCPT ); Sun, 17 Sep 2017 17:07:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=7DRpN656pfHfR18n6NGT0CPRByppBhg7A7vsXGhJm4A=; b=NZotaTIxtRP8nJf4AFg7msjvP vmXz7SNbfWdd8BgBG07hqNpDZVLtyONDalKaeuOz08pR/JjvId7ZZ/Sp9Md4lNzBctbEe+m7DXpE5 rz1v9SF7HK/kCTM/y1LMsjnT6KGZnUDtT3Wrd8v5mGOYZc2ENVs3zCfbUacnm+kvZrfRueS5CnGRJ 4V194sdlmr/U6FP1+0RjkIDiRtuT+QXUwlFwEbrqXVdsWnCULZfeG/HhPFT5HboOLiMrvEjHjFaMK dcKcgMICSwP1klAzBAkFHbV08iNbwMSoGDqtqX+j+ZUJEfx2s4lijxsu29PLmy50a37bpRgjE94Uo RI7WoKkrg==; Received: from [107.17.164.65] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.87 #1 (Red Hat Linux)) id 1dtgmd-0007Yt-Kc; Sun, 17 Sep 2017 21:07:19 +0000 From: Christoph Hellwig To: stable@vger.kernel.org Cc: linux-xfs@vger.kernel.org, Brian Foster , "Darrick J . Wong" Subject: [PATCH 14/47] xfs: fix quotacheck dquot id overflow infinite loop Date: Sun, 17 Sep 2017 14:06:39 -0700 Message-Id: <20170917210712.10804-15-hch@lst.de> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170917210712.10804-1-hch@lst.de> References: <20170917210712.10804-1-hch@lst.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Brian Foster commit cfaf2d034360166e569a4929dd83ae9698bed856 upstream. If a dquot has an id of U32_MAX, the next lookup index increment overflows the uint32_t back to 0. This starts the lookup sequence over from the beginning, repeats indefinitely and results in a livelock. Update xfs_qm_dquot_walk() to explicitly check for the lookup overflow and exit the loop. Signed-off-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_qm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c index 8068867a8183..1fdd3face2d9 100644 --- a/fs/xfs/xfs_qm.c +++ b/fs/xfs/xfs_qm.c @@ -111,6 +111,9 @@ xfs_qm_dquot_walk( skipped = 0; break; } + /* we're done if id overflows back to zero */ + if (!next_index) + break; } if (skipped) {