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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY 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 C69E9C4332B for ; Thu, 19 Mar 2020 15:00:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A945D2072D for ; Thu, 19 Mar 2020 15:00:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727815AbgCSPAn (ORCPT ); Thu, 19 Mar 2020 11:00:43 -0400 Received: from mx2.suse.de ([195.135.220.15]:50444 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727781AbgCSPAm (ORCPT ); Thu, 19 Mar 2020 11:00:42 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id A5FBAAE48; Thu, 19 Mar 2020 15:00:40 +0000 (UTC) Received: from localhost (webern.olymp [local]) by webern.olymp (OpenSMTPD) with ESMTPA id 4a952f62; Thu, 19 Mar 2020 15:00:39 +0000 (WET) Date: Thu, 19 Mar 2020 15:00:39 +0000 From: Luis Henriques To: Jeff Layton Cc: Sage Weil , Ilya Dryomov , "Yan, Zheng" , ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ceph: fix memory leak in ceph_cleanup_snapid_map Message-ID: <20200319150039.GA24696@suse.com> References: <20200319114348.GA72449@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 19, 2020 at 10:41:13AM -0400, Jeff Layton wrote: > On Thu, 2020-03-19 at 11:43 +0000, Luis Henriques wrote: > > kmemleak reports the following memory leak: > > > > unreferenced object 0xffff88821feac8a0 (size 96): > > comm "kworker/1:0", pid 17, jiffies 4294896362 (age 20.512s) > > hex dump (first 32 bytes): > > a0 c8 ea 1f 82 88 ff ff 00 c9 ea 1f 82 88 ff ff ................ > > 00 00 00 00 00 00 00 00 00 01 00 00 00 00 ad de ................ > > backtrace: > > [<00000000b3ea77fb>] ceph_get_snapid_map+0x75/0x2a0 > > [<00000000d4060942>] fill_inode+0xb26/0x1010 > > [<0000000049da6206>] ceph_readdir_prepopulate+0x389/0xc40 > > [<00000000e2fe2549>] dispatch+0x11ab/0x1521 > > [<000000007700b894>] ceph_con_workfn+0xf3d/0x3240 > > [<0000000039138a41>] process_one_work+0x24d/0x590 > > [<00000000eb751f34>] worker_thread+0x4a/0x3d0 > > [<000000007e8f0d42>] kthread+0xfb/0x130 > > [<00000000d49bd1fa>] ret_from_fork+0x3a/0x50 > > > > A kfree was missing in commit 75c9627efb72 ("ceph: map snapid to anonymous > > bdev ID"), while looping the 'to_free' list of ceph_snapid_map objects. > > > > Fixes: 75c9627efb72 ("ceph: map snapid to anonymous bdev ID") > > Signed-off-by: Luis Henriques > > --- > > Hi! > > > > A bit of mailing-list archaeology shows that v1 of this patch actually > > included this kfree [1], and was lost on v2 [2]. > > > > [1] https://patchwork.kernel.org/patch/10114319/ > > [2] https://patchwork.kernel.org/patch/10749907/ > > > > Cheers, > > -- > > Luis > > > > fs/ceph/snap.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c > > index ccfcc66aaf44..923be9399b21 100644 > > --- a/fs/ceph/snap.c > > +++ b/fs/ceph/snap.c > > @@ -1155,5 +1155,6 @@ void ceph_cleanup_snapid_map(struct ceph_mds_client *mdsc) > > pr_err("snapid map %llx -> %x still in use\n", > > sm->snap, sm->dev); > > } > > + kfree(sm); > > } > > } > > Good catch. This looks correct to me. > > Hmmm...we'll leak one of these for every snapid we encounter. Any > objection to marking this for stable? No, please do. I assumed it would be a stable candidate already by having the 'Fixes: ' but maybe it's better to explicitly tag it. Cheers, -- Luis