From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757469AbcBDAAo (ORCPT ); Wed, 3 Feb 2016 19:00:44 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:46392 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756638AbcBCWd7 (ORCPT ); Wed, 3 Feb 2016 17:33:59 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Rabin Vincent , "David S . Miller" , Luis Henriques Subject: [PATCH 3.16.y-ckt 012/180] net: bpf: reject invalid shifts Date: Wed, 3 Feb 2016 22:30:18 +0000 Message-Id: <1454538786-12215-13-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1454538786-12215-1-git-send-email-luis.henriques@canonical.com> References: <1454538786-12215-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt24 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Rabin Vincent commit 229394e8e62a4191d592842cf67e80c62a492937 upstream. On ARM64, a BUG() is triggered in the eBPF JIT if a filter with a constant shift that can't be encoded in the immediate field of the UBFM/SBFM instructions is passed to the JIT. Since these shifts amounts, which are negative or >= regsize, are invalid, reject them in the eBPF verifier and the classic BPF filter checker, for all architectures. Signed-off-by: Rabin Vincent Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller [ luis: backported to 3.16: - drop changes to eBPF verifier, only added in 3.18 kernel - function rename: bpf_check_classic() -> sk_chk_filter() ] Signed-off-by: Luis Henriques --- net/core/filter.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/core/filter.c b/net/core/filter.c index 3139f966a178..dfc5f31dc5a1 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1251,6 +1251,11 @@ int sk_chk_filter(struct sock_filter *filter, unsigned int flen) if (ftest->k == 0) return -EINVAL; break; + case BPF_ALU | BPF_LSH | BPF_K: + case BPF_ALU | BPF_RSH | BPF_K: + if (ftest->k >= 32) + return -EINVAL; + break; case BPF_LD | BPF_MEM: case BPF_LDX | BPF_MEM: case BPF_ST: