Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753978AbcDZU36 (ORCPT ); Tue, 26 Apr 2016 16:29:58 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:58522 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753847AbcDZU0O (ORCPT ); Tue, 26 Apr 2016 16:26:14 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Alexei Starovoitov , "David S . Miller" , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 59/66] bpf/verifier: reject invalid LD_ABS | BPF_DW instruction Date: Tue, 26 Apr 2016 13:24:50 -0700 Message-Id: <1461702297-7792-60-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1461702297-7792-1-git-send-email-kamal@canonical.com> References: <1461702297-7792-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1297 Lines: 35 3.19.8-ckt20 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Alexei Starovoitov commit d82bccc69041a51f7b7b9b4a36db0772f4cdba21 upstream. verifier must check for reserved size bits in instruction opcode and reject BPF_LD | BPF_ABS | BPF_DW and BPF_LD | BPF_IND | BPF_DW instructions, otherwise interpreter will WARN_RATELIMIT on them during execution. Fixes: ddd872bc3098 ("bpf: verifier: add checks for BPF_ABS | BPF_IND instructions") Signed-off-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- kernel/bpf/verifier.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 7f68ff6..0d2cbc9 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1213,6 +1213,7 @@ static int check_ld_abs(struct verifier_env *env, struct bpf_insn *insn) } if (insn->dst_reg != BPF_REG_0 || insn->off != 0 || + BPF_SIZE(insn->code) == BPF_DW || (mode == BPF_ABS && insn->src_reg != BPF_REG_0)) { verbose("BPF_LD_ABS uses reserved fields\n"); return -EINVAL; -- 2.7.4