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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 073FDC352A3 for ; Mon, 10 Feb 2020 14:17:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC2F32080C for ; Mon, 10 Feb 2020 14:17:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727546AbgBJORc (ORCPT ); Mon, 10 Feb 2020 09:17:32 -0500 Received: from ivanoab7.miniserver.com ([37.128.132.42]:41484 "EHLO www.kot-begemot.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727434AbgBJORc (ORCPT ); Mon, 10 Feb 2020 09:17:32 -0500 Received: from tun252.jain.kot-begemot.co.uk ([192.168.18.6] helo=jain.kot-begemot.co.uk) by www.kot-begemot.co.uk with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1j19sL-0004Uz-9I; Mon, 10 Feb 2020 14:17:25 +0000 Received: from jain.kot-begemot.co.uk ([192.168.3.3]) by jain.kot-begemot.co.uk with esmtp (Exim 4.92) (envelope-from ) id 1j19sI-0000TK-TU; Mon, 10 Feb 2020 14:17:25 +0000 Subject: Re: [PATCH v3] um: Fix some error handling in uml_vector_user_bpf() To: Dan Carpenter , Jeff Dike Cc: Richard Weinberger , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , Alex Dewar , linux-um@lists.infradead.org, bpf@vger.kernel.org, kernel-janitors@vger.kernel.org References: <20200128151000.kx2bwayuuxpuqn6t@kili.mountain> From: Anton Ivanov Message-ID: Date: Mon, 10 Feb 2020 14:17:22 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200128151000.kx2bwayuuxpuqn6t@kili.mountain> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Clacks-Overhead: GNU Terry Pratchett Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 28/01/2020 15:27, Dan Carpenter wrote: > 1) The uml_vector_user_bpf() returns pointers so it should return NULL > instead of false. > 2) If the "bpf_prog" allocation failed, it would have eventually lead to > a crash. We can't succeed after the error happens so it should just > return. > > Fixes: 9807019a62dc ("um: Loadable BPF "Firmware" for vector drivers") > Signed-off-by: Dan Carpenter > --- > v3: Fix screwed up subject. Sorry. Not my most shining hour. > v2: The first version broke the build. Shame upon me. > > arch/um/drivers/vector_user.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c > index ddcd917be0af..1403cbadf92b 100644 > --- a/arch/um/drivers/vector_user.c > +++ b/arch/um/drivers/vector_user.c > @@ -732,13 +732,14 @@ void *uml_vector_user_bpf(char *filename) > > if (stat(filename, &statbuf) < 0) { > printk(KERN_ERR "Error %d reading bpf file", -errno); > - return false; > + return NULL; > } > bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL); > - if (bpf_prog != NULL) { > - bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter); > - bpf_prog->filter = NULL; > - } > + if (bpf_prog == NULL) > + return NULL; > + bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter); > + bpf_prog->filter = NULL; > + > ffd = os_open_file(filename, of_read(OPENFLAGS()), 0); > if (ffd < 0) { > printk(KERN_ERR "Error %d opening bpf file", -errno); > Acked-by: Anton Ivanov -- Anton R. Ivanov Cambridgegreys Limited. Registered in England. Company Number 10273661 https://www.cambridgegreys.com/