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[23.128.96.18]) by mx.google.com with ESMTP id e3si10613373ejh.143.2020.06.16.00.09.35; Tue, 16 Jun 2020 00:09:57 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=ZZsayt7b; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727054AbgFPHHu (ORCPT + 99 others); Tue, 16 Jun 2020 03:07:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726747AbgFPHHu (ORCPT ); Tue, 16 Jun 2020 03:07:50 -0400 Received: from mail-io1-xd43.google.com (mail-io1-xd43.google.com [IPv6:2607:f8b0:4864:20::d43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30E3BC05BD43; Tue, 16 Jun 2020 00:07:50 -0700 (PDT) Received: by mail-io1-xd43.google.com with SMTP id w18so693645iom.5; Tue, 16 Jun 2020 00:07:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :content-transfer-encoding; bh=w2GZ9D1qoyvSkgnyjIsWsEO06r80xGwaHHmxaAjuloc=; b=ZZsayt7bxxYDUT0hylS4GIkNoY9UaEBqjyZlYcjF1n2kbPwlgUHVWID4pm2nqznENy lNaCpJ4vEkMn2GTetCOZjieycY1XNMwmHcw3boGkBasHphV+tfbXJG7RR0V4VIaxOUVU RHwBJCgHJUGk1SglNtWwKLrvr9m82qh0t8XqPlBZ2tbjEgp8CcoSyBttRPjytaD718nv IQyJTBOiEesaztsHWYIcHZ65+o+AyVmlmAWnDqIQ7ZEmWaGKnrbzl5yYUy0nm8wXHlwk rMYoHRxEQNaZxCT2ocR3qp8YRmToOUFE02PW+RG19CgjdpTCrCJO1D38Ytekg5+YiHbc Ubmg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:message-id:in-reply-to:references :subject:mime-version:content-transfer-encoding; bh=w2GZ9D1qoyvSkgnyjIsWsEO06r80xGwaHHmxaAjuloc=; b=ZZfY4LL84+kd4V47qEDcKeA+CFtu3l/jOPsLZpz/Sitx0EN6Tzg8HKJYYiFJ+qLqVZ JDyfRCXdbzHhgqWvah962j503MiLv+8UOa8Qof5WC5hR8ZtdhkqAg8qpy/L0/lUQGnJu wl8NrQCNIbr+uf9ENLcKSawcYhb+B29sDIpTRCMTBPAz+ZDimakDiofvEaYLJQzW2Qqq HjNysorSEKRH6f8cV6/TgLqEi+Osw2OZMqZNqiCWSPlZsYkW2y0n7Wk2I7BaDioZqltW DUkQqLpvWjRGkcICB6VHYIC8bID5mnsijB/jrvNwXivO2V5CnltXDif00XRck16rglqO hvfA== X-Gm-Message-State: AOAM533LZsvP1hN3U47SJ4YvGwZv45spKhVebBavtiSNP25mBadTxHzX IQ+Q8b38r8ubZWmLpUBl4eo= X-Received: by 2002:a02:7f4d:: with SMTP id r74mr24426375jac.51.1592291269465; Tue, 16 Jun 2020 00:07:49 -0700 (PDT) Received: from localhost ([184.63.162.180]) by smtp.gmail.com with ESMTPSA id f18sm9242592ion.19.2020.06.16.00.07.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Jun 2020 00:07:48 -0700 (PDT) Date: Tue, 16 Jun 2020 00:07:40 -0700 From: John Fastabend To: Gaurav Singh , 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 , "(open list:BPF \\(Safe dynamic programs and tools\\))" , bpf@vger.kernel.org (open list:BPF \(Safe dynamic programs and tools\)), "(open list:BPF \\(Safe dynamic programs and tools\\) open list)" Message-ID: <5ee86fbc41c03_4be02ab1b668a5b422@john-XPS-13-9370.notmuch> In-Reply-To: <20200614190434.31321-1-gaurav1086@gmail.com> References: <20200614190434.31321-1-gaurav1086@gmail.com> Subject: RE: [PATCH] [bpf] xdp_redirect_cpu_user: Fix null pointer dereference Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Gaurav Singh wrote: > 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 > --- > 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); > -- > 2.17.1 > Acked-by: John Fastabend