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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 3C2D7CA9EA9 for ; Fri, 18 Oct 2019 22:21:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0545C20872 for ; Fri, 18 Oct 2019 22:21:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571437261; bh=LNNQLMxHuH//SF79byo4zmELq1YgTbZqrKBWxPS1E2A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=r201r+s7D0OVBLFqzfvjhsnAhAUc31ZYqY1sbxBIrjTecndTLX2LaC+ntjzcYIU0G jCnB7k9JAI/3tbEWrpDmOlVMQNOZDgrnGpEmNhyO6+HaGkOyx1yggMy7aOy2TzWwD5 gQjxeec0nm4b/82PsukXZnXqVrXEzK7pPahl8+ws= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731591AbfJRWG3 (ORCPT ); Fri, 18 Oct 2019 18:06:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:38228 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731176AbfJRWGR (ORCPT ); Fri, 18 Oct 2019 18:06:17 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EDF942245D; Fri, 18 Oct 2019 22:06:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571436376; bh=LNNQLMxHuH//SF79byo4zmELq1YgTbZqrKBWxPS1E2A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jRGMIYdtROGSkjtkyx3ePTTyBds6rcYNfq4ZzvDykyIlDkC7JKFLKP1i65ZKNuYIA HbWJT+5Jr1KBlc/GRPoYDFgnYMXbA/FdpShX2+fGZ6l5bNmj3KXiD2lMWZdwToLy4Z +39iXdhLffdtDLkrMfORe6VRvj7N0KeD36l2ZizI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Daniel T. Lee" , Song Liu , Daniel Borkmann , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 030/100] samples: bpf: fix: seg fault with NULL pointer arg Date: Fri, 18 Oct 2019 18:04:15 -0400 Message-Id: <20191018220525.9042-30-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191018220525.9042-1-sashal@kernel.org> References: <20191018220525.9042-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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