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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 E6D69C282C8 for ; Mon, 28 Jan 2019 17:28:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BCA8D2147A for ; Mon, 28 Jan 2019 17:28:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730811AbfA1R2T (ORCPT ); Mon, 28 Jan 2019 12:28:19 -0500 Received: from mx2.suse.de ([195.135.220.15]:41742 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730549AbfA1R2R (ORCPT ); Mon, 28 Jan 2019 12:28:17 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 5DB63AF0D; Mon, 28 Jan 2019 17:28:15 +0000 (UTC) Date: Mon, 28 Jan 2019 18:28:14 +0100 (CET) From: Miroslav Benes To: Sasha Levin cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Nicholas Mc Guire , Jiri Kosina , live-patching@vger.kernel.org Subject: Re: [PATCH AUTOSEL 4.19 174/258] livepatch: check kzalloc return values In-Reply-To: <20190128155924.51521-174-sashal@kernel.org> Message-ID: References: <20190128155924.51521-1-sashal@kernel.org> <20190128155924.51521-174-sashal@kernel.org> User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 28 Jan 2019, Sasha Levin wrote: > From: Nicholas Mc Guire > > [ Upstream commit 5f30b2e823484ce6a79f2b59901b6351c15effa6 ] > > kzalloc() return should always be checked - notably in example code > where this may be seen as reference. On failure of allocation in > livepatch_fix1_dummy_alloc() respectively dummy_alloc() previous > allocation is freed (thanks to Petr Mladek for > catching this) and NULL returned. > > Signed-off-by: Nicholas Mc Guire > Fixes: 439e7271dc2b ("livepatch: introduce shadow variable API") > Acked-by: Joe Lawrence > Reviewed-by: Petr Mladek > Acked-by: Miroslav Benes > Signed-off-by: Jiri Kosina > Signed-off-by: Sasha Levin Hi Sasha, I am not sure what stable policy is, but the patch is for samples/ directory and I do not think it is something which should necessarily go to stable. It is your call though. Regards, Miroslav > --- > samples/livepatch/livepatch-shadow-fix1.c | 5 +++++ > samples/livepatch/livepatch-shadow-mod.c | 4 ++++ > 2 files changed, 9 insertions(+) > > diff --git a/samples/livepatch/livepatch-shadow-fix1.c b/samples/livepatch/livepatch-shadow-fix1.c > index 49b13553eaae..e8f1bd6b29b1 100644 > --- a/samples/livepatch/livepatch-shadow-fix1.c > +++ b/samples/livepatch/livepatch-shadow-fix1.c > @@ -89,6 +89,11 @@ struct dummy *livepatch_fix1_dummy_alloc(void) > * pointer to handle resource release. > */ > leak = kzalloc(sizeof(int), GFP_KERNEL); > + if (!leak) { > + kfree(d); > + return NULL; > + } > + > klp_shadow_alloc(d, SV_LEAK, sizeof(leak), GFP_KERNEL, > shadow_leak_ctor, leak); > > diff --git a/samples/livepatch/livepatch-shadow-mod.c b/samples/livepatch/livepatch-shadow-mod.c > index 4c54b250332d..4aa8a88d3cd6 100644 > --- a/samples/livepatch/livepatch-shadow-mod.c > +++ b/samples/livepatch/livepatch-shadow-mod.c > @@ -118,6 +118,10 @@ noinline struct dummy *dummy_alloc(void) > > /* Oops, forgot to save leak! */ > leak = kzalloc(sizeof(int), GFP_KERNEL); > + if (!leak) { > + kfree(d); > + return NULL; > + } > > pr_info("%s: dummy @ %p, expires @ %lx\n", > __func__, d, d->jiffies_expire); > -- > 2.19.1 >