Return-Path: Received: from fieldses.org ([173.255.197.46]:36446 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729907AbeGQKpN (ORCPT ); Tue, 17 Jul 2018 06:45:13 -0400 Date: Tue, 17 Jul 2018 06:13:20 -0400 From: "J . Bruce Fields" To: Colin Ian King Cc: Dan Carpenter , Jeff Layton , linux-nfs@vger.kernel.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, Olga Kornievskaia Subject: Re: [PATCH] nfsd: fix memory leak of async_copy Message-ID: <20180717101320.GB30192@fieldses.org> References: <20180716120954.6720-1-colin.king@canonical.com> <20180717093005.3ggy24fskb3bxtni@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: Cc'ing Olga.--b. On Tue, Jul 17, 2018 at 10:33:59AM +0100, Colin Ian King wrote: > On 17/07/18 10:30, Dan Carpenter wrote: > > On Mon, Jul 16, 2018 at 01:09:54PM +0100, Colin King wrote: > >> From: Colin Ian King > >> > >> In the case where async_copy is successfully allocated but > >> the call to nfs4_init_cp_state fails, async_copy is not > >> currently freed and the memory is leaked. Fix this by kfree'ing > >> it before returning. > >> > >> Detected by CoverityScan, CID#1471823 ("Resource leak") > >> > >> Fixes: beb1814d5a8a ("NFSD create new stateid for async copy") > >> Signed-off-by: Colin Ian King > >> --- > >> fs/nfsd/nfs4proc.c | 4 +++- > >> 1 file changed, 3 insertions(+), 1 deletion(-) > >> > >> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c > >> index 8f3368353aaf..3fb96a2708b9 100644 > >> --- a/fs/nfsd/nfs4proc.c > >> +++ b/fs/nfsd/nfs4proc.c > >> @@ -1295,8 +1295,10 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > >> async_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL); > >> if (!async_copy) > >> goto out; > >> - if (!nfs4_init_cp_state(nn, copy)) > >> + if (!nfs4_init_cp_state(nn, copy)) { > >> + kfree(async_copy); > >> goto out; > > > > It really feels like both this and the kzalloc() failure should be doing > > an of fput() of copy->file_src and copy->file_dst. The goto out_err > > does an list_del(©->copies); but it happens before the > > "list_add(&async_copy->copies ..." so that's likely wrong as well. > > Good observation, thanks for spotting that. I suspect I'm a bit out of > my depth figuring out the exact error handling reaping steps here. > Perhaps this is one for the maintainers to figure out a safe cleanup on > these error paths. > > > > > regards, > > dan carpenter > > > > -- > > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > >