Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3564C4332F for ; Wed, 24 Nov 2021 12:16:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242624AbhKXMT3 (ORCPT ); Wed, 24 Nov 2021 07:19:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:37610 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242373AbhKXMOe (ORCPT ); Wed, 24 Nov 2021 07:14:34 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id F0F7E610E6; Wed, 24 Nov 2021 12:09:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637755767; bh=VI8v5IQiu/tKA0vNkfX5roS+XnOk7u4BuOYg353jHys=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xZLZ5Z7OR7FTuF6RnCUsYYyUiorPJP6ZJyTUREa2rjmEN0z4wVu2f0kP6REpNjXoi Z1UcAGWoMh9amN/R6YwqpL8In2ZAVcrzCsyWhWBOfMXYg+t7HSlGSYAwH9y95TU6T7 3dXknnq3q2Tbk7P3rQ6+cVoLu6sJHwQO6SU6K+/A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lorenz Bauer , Alexei Starovoitov , Sasha Levin Subject: [PATCH 4.9 022/207] bpf: Prevent increasing bpf_jit_limit above max Date: Wed, 24 Nov 2021 12:54:53 +0100 Message-Id: <20211124115704.683110716@linuxfoundation.org> X-Mailer: git-send-email 2.34.0 In-Reply-To: <20211124115703.941380739@linuxfoundation.org> References: <20211124115703.941380739@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lorenz Bauer [ Upstream commit fadb7ff1a6c2c565af56b4aacdd086b067eed440 ] Restrict bpf_jit_limit to the maximum supported by the arch's JIT. Signed-off-by: Lorenz Bauer Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20211014142554.53120-4-lmb@cloudflare.com Signed-off-by: Sasha Levin --- include/linux/filter.h | 1 + kernel/bpf/core.c | 4 +++- net/core/sysctl_net_core.c | 2 +- 3 files changed, 5 insertions(+), 2 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index 0837d904405a3..05be3d84655e4 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -600,6 +600,7 @@ void bpf_warn_invalid_xdp_action(u32 act); extern int bpf_jit_enable; extern int bpf_jit_harden; extern long bpf_jit_limit; +extern long bpf_jit_limit_max; typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index df2ebce927ec4..3ce69c0276c09 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -212,6 +212,7 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON); int bpf_jit_harden __read_mostly; long bpf_jit_limit __read_mostly; +long bpf_jit_limit_max __read_mostly; static atomic_long_t bpf_jit_current; @@ -231,7 +232,8 @@ u64 __weak bpf_jit_alloc_exec_limit(void) static int __init bpf_jit_charge_init(void) { /* Only used as heuristic here to derive limit. */ - bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2, + bpf_jit_limit_max = bpf_jit_alloc_exec_limit(); + bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 2, PAGE_SIZE), LONG_MAX); return 0; } diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index b4318c1b5b960..f62e177267c34 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -368,7 +368,7 @@ static struct ctl_table net_core_table[] = { .mode = 0600, .proc_handler = proc_dolongvec_minmax_bpf_restricted, .extra1 = &long_one, - .extra2 = &long_max, + .extra2 = &bpf_jit_limit_max, }, #endif { -- 2.33.0