From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42902 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753727AbcA0Ge2 (ORCPT ); Wed, 27 Jan 2016 01:34:28 -0500 Subject: Patch "net: bpf: reject invalid shifts" has been added to the 4.3-stable tree To: rabin@rab.in, ast@kernel.org, daniel@iogearbox.net, davem@davemloft.net, gregkh@linuxfoundation.org Cc: , From: Date: Tue, 26 Jan 2016 22:29:12 -0800 Message-ID: <1453876152120167@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled net: bpf: reject invalid shifts to the 4.3-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-bpf-reject-invalid-shifts.patch and it can be found in the queue-4.3 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Tue Jan 26 21:35:03 PST 2016 From: Rabin Vincent Date: Tue, 12 Jan 2016 20:17:08 +0100 Subject: net: bpf: reject invalid shifts From: Rabin Vincent [ Upstream commit 229394e8e62a4191d592842cf67e80c62a492937 ] 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 Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/verifier.c | 10 ++++++++++ net/core/filter.c | 5 +++++ 2 files changed, 15 insertions(+) --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1058,6 +1058,16 @@ static int check_alu_op(struct reg_state return -EINVAL; } + if ((opcode == BPF_LSH || opcode == BPF_RSH || + opcode == BPF_ARSH) && BPF_SRC(insn->code) == BPF_K) { + int size = BPF_CLASS(insn->code) == BPF_ALU64 ? 64 : 32; + + if (insn->imm < 0 || insn->imm >= size) { + verbose("invalid shift %d\n", insn->imm); + return -EINVAL; + } + } + /* pattern match 'bpf_add Rx, imm' instruction */ if (opcode == BPF_ADD && BPF_CLASS(insn->code) == BPF_ALU64 && regs[insn->dst_reg].type == FRAME_PTR && --- a/net/core/filter.c +++ b/net/core/filter.c @@ -781,6 +781,11 @@ static int bpf_check_classic(const struc 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: Patches currently in stable-queue which might be from rabin@rab.in are queue-4.3/net-filter-make-jits-zero-a-for-skf_ad_alu_xor_x.patch queue-4.3/net-bpf-reject-invalid-shifts.patch