From patchwork Sun Jun 14 19:04:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gaurav Singh X-Patchwork-Id: 1309062 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=O4f0no9g; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49lP64696fz9sQx for ; Mon, 15 Jun 2020 05:04:44 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727820AbgFNTEn (ORCPT ); Sun, 14 Jun 2020 15:04:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727036AbgFNTEn (ORCPT ); Sun, 14 Jun 2020 15:04:43 -0400 Received: from mail-qt1-x844.google.com (mail-qt1-x844.google.com [IPv6:2607:f8b0:4864:20::844]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 46F6EC08C5C2; Sun, 14 Jun 2020 12:04:42 -0700 (PDT) Received: by mail-qt1-x844.google.com with SMTP id g62so10990538qtd.5; Sun, 14 Jun 2020 12:04:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id; bh=ZMcCnhw+cb0GssjRbz2Uvr23jd5CfAqDE459LKY1/1g=; b=O4f0no9gkSjNwQeZuPS7lBS877ehntOkn4Y5ujlumfsbRYOyrEHldqHzVigXDiSSe5 HhxT6u2hr+AuZ0+KYXJ9gZg50GjPXIXjFPRu5PrrdzoE0TWBpM7BTmYhrol1vSEtyBB7 GXIiydsljflA1rCzKioD+ROrAaDY1N3lFj84zaVkfA+qS0H/qNUGeUaJTM/PCa6NMipj Af9s+hXy1V0BGUk5UEUONvLJnC2fhKJl63LFthHX+yBHq9f6bWAY44vjiljDVLEl7fS2 mLnx0mKPuHa45xSY+Z/GBeTouuADZUoda6QuaueFNpJngGh9rtiqErlgbom3mCeNIAsR XTrg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id; bh=ZMcCnhw+cb0GssjRbz2Uvr23jd5CfAqDE459LKY1/1g=; b=q1bDEQTCznZFpHNf5NFy3ybmlsL+dNOqHBci7T/XnXInTR0tSHTEytc1q0CP2ZMfkA wVhsn19jV0jxAnpiEPel0JWgxLPkgrCD41UZmNbT/+25ewSg9ZjJc1JEMJlOxJfn2rrh 08b6lqd9ui7n0jcTBksshgNjV5rpQTPoAgsut/gqz1+R5fTPMsTrrmOvTvn7EVTglnOz dLnz2ZUkshx1QAjpUrsTMkm00i3dHCxs4kiM/oYEQ4Kf/VfUrR1GvSpkcExbVl0vP18O 9LMqHFslauDWUmE5SQeljYLA0tQDFLE1t90lD/qYk/jIFOOw2xrPw3dleChNJEmWOibw wX/Q== X-Gm-Message-State: AOAM532S0fOLUSOO2lGaeYxrkZvsBt2LgpQ92W31igdMU8+n0Vp03isv z/jGT/uQc/kLsld8LRGomRQ= X-Google-Smtp-Source: ABdhPJzsFCo/ACyKhmF/+97h8AR6FsA+85GRPNjWIzqOnbnbnw/hF3IHAduxaMCZIKMEAVwtcT+aQQ== X-Received: by 2002:ac8:3551:: with SMTP id z17mr12429782qtb.139.1592161481533; Sun, 14 Jun 2020 12:04:41 -0700 (PDT) Received: from linux.home ([2604:2000:1344:41d:b556:165b:f409:9052]) by smtp.googlemail.com with ESMTPSA id i40sm10953911qte.67.2020.06.14.12.04.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 14 Jun 2020 12:04:40 -0700 (PDT) From: Gaurav Singh To: gaurav1086@gmail.com, Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , John Fastabend , KP Singh , "David S. Miller" , Jakub Kicinski , Jesper Dangaard Brouer , netdev@vger.kernel.org (open list:BPF (Safe dynamic programs and tools)), bpf@vger.kernel.org (open list:BPF (Safe dynamic programs and tools)), linux-kernel@vger.kernel.org (open list) Subject: [PATCH] [bpf] xdp_redirect_cpu_user: Fix null pointer dereference Date: Sun, 14 Jun 2020 15:04:33 -0400 Message-Id: <20200614190434.31321-1-gaurav1086@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Memset() on the pointer right after malloc() can cause a null pointer dereference if it failed to allocate memory. Fix this by replacing malloc/memset with a single calloc(). Signed-off-by: Gaurav Singh Acked-by: John Fastabend --- samples/bpf/xdp_redirect_cpu_user.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/samples/bpf/xdp_redirect_cpu_user.c b/samples/bpf/xdp_redirect_cpu_user.c index f3468168982e..2ae7a9a1d950 100644 --- a/samples/bpf/xdp_redirect_cpu_user.c +++ b/samples/bpf/xdp_redirect_cpu_user.c @@ -207,11 +207,8 @@ static struct datarec *alloc_record_per_cpu(void) { unsigned int nr_cpus = bpf_num_possible_cpus(); struct datarec *array; - size_t size; - size = sizeof(struct datarec) * nr_cpus; - array = malloc(size); - memset(array, 0, size); + array = calloc(nr_cpus, sizeof(struct datarec)); if (!array) { fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus); exit(EXIT_FAIL_MEM); @@ -222,11 +219,9 @@ static struct datarec *alloc_record_per_cpu(void) static struct stats_record *alloc_stats_record(void) { struct stats_record *rec; - int i, size; + int i; - size = sizeof(*rec) + n_cpus * sizeof(struct record); - rec = malloc(size); - memset(rec, 0, size); + rec = calloc(n_cpus + 1, sizeof(struct record)); if (!rec) { fprintf(stderr, "Mem alloc error\n"); exit(EXIT_FAIL_MEM);