From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 14 Nov 2016 03:08:35 +0100 (CET) Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:38378 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23990720AbcKNCEklW8jO (ORCPT ); Mon, 14 Nov 2016 03:04:40 +0100 Received: from [2a02:8011:400e:2:6f00:88c8:c921:d332] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1c66d2-0005fH-ED; Mon, 14 Nov 2016 02:04:12 +0000 Received: from ben by deadeye with local (Exim 4.87) (envelope-from ) id 1c66d1-0000Oj-MD; Mon, 14 Nov 2016 02:04:11 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Alexei Starovoitov" , "Daniel Borkmann" , linux-mips@linux-mips.org, "Ralf Baechle" , "Dan Carpenter" Date: Mon, 14 Nov 2016 00:14:20 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 101/346] bpf, mips: fix off-by-one in ctx offset allocation In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 55804 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ben@decadent.org.uk Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips 3.16.39-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Borkmann commit b4e76f7e6d3200462c6354a6ad4ae167459e61f8 upstream. Dan Carpenter reported [1] a static checker warning that ctx->offsets[] may be accessed off by one from build_body(), since it's allocated with fp->len * sizeof(*ctx.offsets) as length. The cBPF arm and ppc code doesn't have this issue as claimed, so only mips seems to be affected and should like most other JITs allocate with fp->len + 1. A few number of JITs (x86, sparc, arm64) handle this differently, where they only require fp->len array elements. [1] http://www.spinics.net/lists/mips/msg64193.html Fixes: c6610de353da ("MIPS: net: Add BPF JIT") Reported-by: Dan Carpenter Signed-off-by: Daniel Borkmann Cc: Alexei Starovoitov Cc: ast@kernel.org Cc: linux-mips@linux-mips.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13814/ Signed-off-by: Ralf Baechle Signed-off-by: Ben Hutchings --- arch/mips/net/bpf_jit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/mips/net/bpf_jit.c +++ b/arch/mips/net/bpf_jit.c @@ -1365,7 +1365,7 @@ void bpf_jit_compile(struct sk_filter *f memset(&ctx, 0, sizeof(ctx)); - ctx.offsets = kcalloc(fp->len, sizeof(*ctx.offsets), GFP_KERNEL); + ctx.offsets = kcalloc(fp->len + 1, sizeof(*ctx.offsets), GFP_KERNEL); if (ctx.offsets == NULL) return;