From patchwork Thu Dec 6 09:27:32 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sandipan Das X-Patchwork-Id: 1008661 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 439Vct1vPRz9s7h for ; Thu, 6 Dec 2018 20:27:42 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729127AbeLFJ1k (ORCPT ); Thu, 6 Dec 2018 04:27:40 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:50286 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727806AbeLFJ1k (ORCPT ); Thu, 6 Dec 2018 04:27:40 -0500 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wB69Nnfl001864 for ; Thu, 6 Dec 2018 04:27:39 -0500 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0b-001b2d01.pphosted.com with ESMTP id 2p6yd5w7gw-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 06 Dec 2018 04:27:39 -0500 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 6 Dec 2018 09:27:37 -0000 Received: from b06cxnps3075.portsmouth.uk.ibm.com (9.149.109.195) by e06smtp04.uk.ibm.com (192.168.101.134) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 6 Dec 2018 09:27:35 -0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id wB69RYq234734192 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 6 Dec 2018 09:27:34 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A90C3A4040; Thu, 6 Dec 2018 09:27:34 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 71B9BA4055; Thu, 6 Dec 2018 09:27:33 +0000 (GMT) Received: from localhost.localdomain (unknown [9.195.22.129]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 6 Dec 2018 09:27:33 +0000 (GMT) From: Sandipan Das To: daniel@iogearbox.net, ast@kernel.org Cc: netdev@vger.kernel.org, linuxppc-dev@ozlabs.org, mpe@ellerman.id.au, naveen.n.rao@linux.ibm.com Subject: [PATCH bpf] bpf: fix default unprivileged allocation limit Date: Thu, 6 Dec 2018 14:57:32 +0530 X-Mailer: git-send-email 2.19.2 MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 18120609-0016-0000-0000-00000232DB77 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18120609-0017-0000-0000-0000328AF149 Message-Id: <20181206092732.4206-1-sandipan@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-12-06_03:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=935 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1812060085 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When using a large page size, the default value of the bpf_jit_limit knob becomes invalid and users are not able to run unprivileged bpf programs. The bpf_jit_limit knob is represented internally as a 32-bit signed integer because of which the default value, i.e. PAGE_SIZE * 40000, overflows in case of an architecture like powerpc64 which uses 64K as the default page size (i.e. CONFIG_PPC_64K_PAGES is set). So, instead of depending on the page size, use a constant value. Fixes: ede95a63b5e8 ("bpf: add bpf_jit_limit knob to restrict unpriv allocations") Signed-off-by: Sandipan Das --- kernel/bpf/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index b1a3545d0ec8..a81d097a17fb 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -365,7 +365,7 @@ void bpf_prog_kallsyms_del_all(struct bpf_prog *fp) } #ifdef CONFIG_BPF_JIT -# define BPF_JIT_LIMIT_DEFAULT (PAGE_SIZE * 40000) +# define BPF_JIT_LIMIT_DEFAULT (4096 * 40000) /* All BPF JIT sysctl knobs here. */ int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON);