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 D3217C4332F for ; Wed, 24 Nov 2021 12:53:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346574AbhKXM4Y (ORCPT ); Wed, 24 Nov 2021 07:56:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:56444 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345029AbhKXMwi (ORCPT ); Wed, 24 Nov 2021 07:52:38 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1E427610E6; Wed, 24 Nov 2021 12:30:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637757030; bh=Arw9kHRt2fdeYw1xCzxytQQSnTL6rVK5U098zfeaiFA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Tn2h8UhSSgJ4AE6eiFLCrEFovbGjqkzuv23uwoZeAjc6bFN06wH0cFdnEyWVAQOZQ 5hl2Wwu+xSgvYxY6iEqhsYEZva/X8QbIlO4O0Uuf3kkzAnTyfGFUgtQhbH9WZSnQ2K cEdDDisnkQ4yXif+dsVULmiepWmPBk44JrNytxlQ= 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 4.19 033/323] bpf: Prevent increasing bpf_jit_limit above max Date: Wed, 24 Nov 2021 12:53:43 +0100 Message-Id: <20211124115719.987798575@linuxfoundation.org> X-Mailer: git-send-email 2.34.0 In-Reply-To: <20211124115718.822024889@linuxfoundation.org> References: <20211124115718.822024889@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 e981bd92a4e3a..89a6ef659b4ca 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -877,6 +877,7 @@ 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 341402bc1202d..4e5b5ae05406e 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -372,6 +372,7 @@ 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, @@ -598,7 +599,8 @@ 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 2597449ae9b48..0a0bf80623658 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -417,7 +417,7 @@ 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