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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 5202FC4320A for ; Mon, 30 Aug 2021 10:14:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3796D610A1 for ; Mon, 30 Aug 2021 10:14:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236342AbhH3KPm (ORCPT ); Mon, 30 Aug 2021 06:15:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45218 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236316AbhH3KPk (ORCPT ); Mon, 30 Aug 2021 06:15:40 -0400 Received: from mail-io1-xd2d.google.com (mail-io1-xd2d.google.com [IPv6:2607:f8b0:4864:20::d2d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B430C061575; Mon, 30 Aug 2021 03:14:47 -0700 (PDT) Received: by mail-io1-xd2d.google.com with SMTP id q3so19064906iot.3; Mon, 30 Aug 2021 03:14:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=X8UjoR+cxk9dXaV8b/ZX2ooM+v51xP64NJ+eDD8X3xA=; b=kFazPhcqZKP4SjeyC0vPyoENZupRq10KVhvxutm3YwW7dTSqsLncMJicy6FcL+7hok gV+bkHLXToMmKPM5wuPnvBe6fEDML6OemIjq716C9PtG+j9KY8GbZxPbSpLxsBLM06Lp wjm+YwsjevoG/fewf6S9RB6wsedeuoSH2vMwgnvuYJ0mUYEHW7+mpmZkAwLZlyLRYq+d V+00boN/yj4vVcKlUIAP8X+MS22RIO/t8u1RLmnWhDKBCDNbEJwPcifE3mVN/YkFYA3L NHkO1EkYG4YqPsEkfhmslFESkpDjD3cTWrtflSId2SfhpAG60m/QHgPu6uYjsCHwFKiH D0tA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=X8UjoR+cxk9dXaV8b/ZX2ooM+v51xP64NJ+eDD8X3xA=; b=qeKJI9YuPUgT744ejQH3MbDSVqTDFy09swDzrrVaWU5u+Aw3RMR2x5eu4JjRtYx9Zb oZvHOMbUWRMTWZYRBE+y6FN6OFAyTXp6CjivcXg0TAdfMOLWJn4nLlV/lH5oJ7l8nqLv 4zBSjkt7tcLkj4GyjoLohSaVH2GNAKgdYSVneILavddSTDcdfKXMewxDdfTZKh6nBqXE KpE1wUTloGUA+Geg68P77eIzTxeASZPnY3vzXdECQ4z+y49wIUd7wr0DN9KtYkazB223 EgOtnG7m/dzFmwhUuzII7+xi4FfE8lgFv4rON/Kxdc6Q+THh2y6yiYEAqlYDfFlRWJ9m onaw== X-Gm-Message-State: AOAM533+UH13+8QFlM6cFmB6+KSOUgavY99clWyesajCsUwtQr0wkW3P cTQ9bpV18lphmUXGWtvyD8Yp4Vw6k98cx76vpWM= X-Google-Smtp-Source: ABdhPJy9ZhcxG3nwBOzHBwk609HqrVKr6kxs+KBqO+rIhtDT+UkIbCxzcQNxSnD/cwxZZoO/yvuBXQh8w61REiD5dt4= X-Received: by 2002:a02:b183:: with SMTP id t3mr4387131jah.93.1630318481377; Mon, 30 Aug 2021 03:14:41 -0700 (PDT) MIME-Version: 1.0 References: <20210829181824.534447-1-colin.king@canonical.com> In-Reply-To: <20210829181824.534447-1-colin.king@canonical.com> From: Ilya Dryomov Date: Mon, 30 Aug 2021 12:14:20 +0200 Message-ID: Subject: Re: [PATCH][next] ceph: Fix dereference of null pointer cf To: Colin King Cc: Jeff Layton , Xiubo Li , Ceph Development , kernel-janitors@vger.kernel.org, LKML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Aug 29, 2021 at 8:18 PM Colin King wrote: > > From: Colin Ian King > > Currently in the case where kmem_cache_alloc fails the null pointer > cf is dereferenced when assigning cf->is_capsnap = false. Fix this > by adding a null pointer check and return path. > > Addresses-Coverity: ("Dereference null return") > Fixes: b2f9fa1f3bd8 ("ceph: correctly handle releasing an embedded cap flush") > Signed-off-by: Colin Ian King > --- > fs/ceph/caps.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c > index 39db97f149b9..eceb3ceaac48 100644 > --- a/fs/ceph/caps.c > +++ b/fs/ceph/caps.c > @@ -1746,6 +1746,8 @@ struct ceph_cap_flush *ceph_alloc_cap_flush(void) > struct ceph_cap_flush *cf; > > cf = kmem_cache_alloc(ceph_cap_flush_cachep, GFP_KERNEL); > + if (!cf) > + return NULL; > cf->is_capsnap = false; > return cf; > } > -- > 2.32.0 > Hi Colin, I guess we were too focused on the details of b2f9fa1f3bd8 to spot the obvious... It sat in next for a few days but apparently not enough to be included in the Coverity run. What is the frequency of these runs? Applied and added an explicit stable tag since b2f9fa1f3bd8 is already on its way to stable kernels. Thanks, Ilya