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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 74D06C43441 for ; Tue, 13 Nov 2018 09:29:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 431C322419 for ; Tue, 13 Nov 2018 09:29:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 431C322419 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=canonical.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731578AbeKMT0o (ORCPT ); Tue, 13 Nov 2018 14:26:44 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:41476 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731476AbeKMT0o (ORCPT ); Tue, 13 Nov 2018 14:26:44 -0500 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1gMV0h-0004qR-9H; Tue, 13 Nov 2018 09:29:27 +0000 From: Colin King To: Alexei Starovoitov , Daniel Borkmann , netdev@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][bpf-next] bpf: fix null pointer dereference on pointer offload Date: Tue, 13 Nov 2018 09:29:26 +0000 Message-Id: <20181113092926.27081-1-colin.king@canonical.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King Pointer offload is being null checked however the following statement dereferences the potentially null pointer offload when assigning offload->dev_state. Fix this by only assigning it if offload is not null. Detected by CoverityScan, CID#1475437 ("Dereference after null check") Fixes: 00db12c3d141 ("bpf: call verifier_prep from its callback in struct bpf_offload_dev") Signed-off-by: Colin Ian King --- kernel/bpf/offload.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c index 52c5617e3716..54cf2b9c44a4 100644 --- a/kernel/bpf/offload.c +++ b/kernel/bpf/offload.c @@ -130,9 +130,10 @@ int bpf_prog_offload_verifier_prep(struct bpf_prog *prog) down_read(&bpf_devs_lock); offload = prog->aux->offload; - if (offload) + if (offload) { ret = offload->offdev->ops->prepare(prog); - offload->dev_state = !ret; + offload->dev_state = !ret; + } up_read(&bpf_devs_lock); return ret; -- 2.19.1