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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A0FBC433FE for ; Mon, 15 Nov 2021 17:17:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DCFE61105 for ; Mon, 15 Nov 2021 17:17:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237202AbhKORUN (ORCPT ); Mon, 15 Nov 2021 12:20:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:47250 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236785AbhKORMo (ORCPT ); Mon, 15 Nov 2021 12:12:44 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7541E61BFE; Mon, 15 Nov 2021 17:09:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636996189; bh=Ve71V7Dm9FEppo7/zAtnlurAELEtRt/pR74sh4jrHDE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lbhNuTNND+XJdygdLcT/OA72qczBP7HpFxAEMyVcEsE2S9lcsJ+CSVKTMhuBHuKPx bF7N78YoL/2Jc5HERPLRQhCjwcEXfYUIOjqEVUNF26JzQtdysvAEnInfCbpKiSipWz OX+K4SXrPj7HMDAvFxBRM+ibiCgakyHOkeva7/z0= 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 5.4 048/355] bpf: Prevent increasing bpf_jit_limit above max Date: Mon, 15 Nov 2021 17:59:32 +0100 Message-Id: <20211115165315.104875576@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165313.549179499@linuxfoundation.org> References: <20211115165313.549179499@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 c4f89340f4986..440014875acf4 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -952,6 +952,7 @@ extern int bpf_jit_enable; extern int bpf_jit_harden; extern int bpf_jit_kallsyms; 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 d9a3d995bd966..1238ef9c569df 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -523,6 +523,7 @@ int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON); int bpf_jit_harden __read_mostly; int bpf_jit_kallsyms __read_mostly; long bpf_jit_limit __read_mostly; +long bpf_jit_limit_max __read_mostly; static __always_inline void bpf_get_prog_addr_region(const struct bpf_prog *prog, @@ -759,7 +760,8 @@ 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 669cbe1609d9e..48041f50ecfb4 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -424,7 +424,7 @@ 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