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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 79E0DCA9EC9 for ; Mon, 4 Nov 2019 21:58:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 40196217F4 for ; Mon, 4 Nov 2019 21:58:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572904725; bh=dNn/LIJ/CoShNtr+baPOMrLT5mYlfNxfN/Toz60p2fQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tmChodwB2aV+Vos8i9apVOrp08r8Ui06Tv2mfA7d27QILaavYaXWyqXdqENqbFDcC 08fDqU5pmeVcYDcL6FtYSArrhcOZAtDozo9B1VJYl1UsheEYI0fBIvt88mLeOA3axv Dz8jBjM6SJnzZoshEwLwNCl/46VN/auQg1wov8JM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730728AbfKDV6o (ORCPT ); Mon, 4 Nov 2019 16:58:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:55640 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388089AbfKDV6g (ORCPT ); Mon, 4 Nov 2019 16:58:36 -0500 Received: from localhost (6.204-14-84.ripe.coltfrance.com [84.14.204.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9B04920650; Mon, 4 Nov 2019 21:58:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572904716; bh=dNn/LIJ/CoShNtr+baPOMrLT5mYlfNxfN/Toz60p2fQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hoxlMktaeHSWRA3kupu4Rnk3YMoFDC28FWCaXlqBYBxLzNDCzPTfCNmkEsGvrAv2D UAp87iAf42e2xlgUK3cNvCPK0VD36Li7v7oDp3bPfLpu2uHpxtaJjfvF9tyWOcK8b6 b4xkU3+H+bzGm7U1z8+iXXcbP1+dp5mUw8nQWMr4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Daniel T. Lee" , Song Liu , Daniel Borkmann , Sasha Levin Subject: [PATCH 4.19 037/149] samples: bpf: fix: seg fault with NULL pointer arg Date: Mon, 4 Nov 2019 22:43:50 +0100 Message-Id: <20191104212138.357301251@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191104212126.090054740@linuxfoundation.org> References: <20191104212126.090054740@linuxfoundation.org> User-Agent: quilt/0.66 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: Daniel T. Lee [ Upstream commit d59dd69d5576d699d7d3f5da0b4738c3a36d0133 ] When NULL pointer accidentally passed to write_kprobe_events, due to strlen(NULL), segmentation fault happens. Changed code returns -1 to deal with this situation. Bug issued with Smatch, static analysis. Signed-off-by: Daniel T. Lee Acked-by: Song Liu Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- samples/bpf/bpf_load.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c index 5061a2ec45646..176c04a454dc9 100644 --- a/samples/bpf/bpf_load.c +++ b/samples/bpf/bpf_load.c @@ -59,7 +59,9 @@ static int write_kprobe_events(const char *val) { int fd, ret, flags; - if ((val != NULL) && (val[0] == '\0')) + if (val == NULL) + return -1; + else if (val[0] == '\0') flags = O_WRONLY | O_TRUNC; else flags = O_WRONLY | O_APPEND; -- 2.20.1