From patchwork Mon Oct 10 12:56:39 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: kernel@kyup.com X-Patchwork-Id: 9369465 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 B67E4607D2 for ; Mon, 10 Oct 2016 12:57:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A79332954C for ; Mon, 10 Oct 2016 12:57:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9C07829564; Mon, 10 Oct 2016 12:57:08 +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=-6.4 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM 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 220932954C for ; Mon, 10 Oct 2016 12:57:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752357AbcJJM4s (ORCPT ); Mon, 10 Oct 2016 08:56:48 -0400 Received: from mail-qt0-f170.google.com ([209.85.216.170]:33477 "EHLO mail-qt0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752002AbcJJM4r (ORCPT ); Mon, 10 Oct 2016 08:56:47 -0400 Received: by mail-qt0-f170.google.com with SMTP id s49so52092196qta.0 for ; Mon, 10 Oct 2016 05:56:46 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=CRA8ICPFP6cwbbWZexROf8sNypjNE7lBsMR2DxQTSco=; b=Ulad5MZp5Mf0od3fBxv/twN7ub7Qam9EDM+5+iUNsqUo2pVe1tNXl6HMvoTKaO00hc HYm+0wuoTUahHgvy7wDrYB8DVoEZ4JU6UAZIss91OwtCV0Vfq/QSwkC6Oxa/zqkq2sAK bPJJxXH/l3d1rDCHRumdlEUg4tzRtoOce51Wm82uZTdP2tRTPCUGqechRmnZ33CsRLSd yYvikyE7QyonGihWGGArdXTsXJf9EskMcmrBkcX9iHn89+F4k5LzRoQfS/aYxZgzJJpV MY6f36qEf5ASsS5qa3N2Rqh9FWIET8b1eIiknNGHK0p2jUkWsLSW7l+3qUoGBxx5LarQ YStg== X-Gm-Message-State: AA6/9Rk3HBRORObfAMMZ3e8ZumiFSIvtMAyBIKgz3B2SYBjXFCgpaklTEoMhqrYFyiUbbO7q X-Received: by 10.194.16.161 with SMTP id h1mr30205767wjd.164.1476104205678; Mon, 10 Oct 2016 05:56:45 -0700 (PDT) Received: from localhost.localdomain (admins.1h.com. [82.118.240.130]) by smtp.gmail.com with ESMTPSA id uw3sm40085514wjb.21.2016.10.10.05.56.44 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 10 Oct 2016 05:56:45 -0700 (PDT) From: Nikolay Borisov To: zyan@redhat.com, idryomov@gmail.com Cc: ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org, Nikolay Borisov Subject: [PATCHv2] ceph: Fix error handling in ceph_read_iter Date: Mon, 10 Oct 2016 15:56:39 +0300 Message-Id: <1476104199-3259-1-git-send-email-kernel@kyup.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1476103098-2925-1-git-send-email-kernel@kyup.com> References: <1476103098-2925-1-git-send-email-kernel@kyup.com> Sender: ceph-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In case __ceph_do_getattr returns an error and the retry_op in ceph_read_iter is not READ_INLINE, then it's possible to invoke __free_page on a page which is NULL, this naturally leads to a crash. This can happen when, for example, a process waiting on a MDS reply receives sigterm. Fix this by explicitly checking whether the page is set or not. Signed-off-by: Nikolay Borisov Link: http://www.spinics.net/lists/ceph-users/msg31592.html Reviewed-by: Yan, Zheng --- Inverted the condition, so resending with correct condition this time. fs/ceph/file.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 3c68e6aee2f0..7413313ae6c8 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -929,7 +929,8 @@ again: statret = __ceph_do_getattr(inode, page, CEPH_STAT_CAP_INLINE_DATA, !!page); if (statret < 0) { - __free_page(page); + if (page) + __free_page(page); if (statret == -ENODATA) { BUG_ON(retry_op != READ_INLINE); goto again;