From mboxrd@z Thu Jan 1 00:00:00 1970 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 386D3C32772 for ; Tue, 23 Aug 2022 19:31:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231209AbiHWTbU (ORCPT ); Tue, 23 Aug 2022 15:31:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48638 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233888AbiHWTa4 (ORCPT ); Tue, 23 Aug 2022 15:30:56 -0400 Received: from smtp-fw-80006.amazon.com (smtp-fw-80006.amazon.com [99.78.197.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9B8F8DB7DD; Tue, 23 Aug 2022 11:21:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1661278892; x=1692814892; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=n+mG2Qf5W8rDz33cIplaqij+OZcyCF2mnob3OKVLXm0=; b=KxdSraNriWDttOpNWfBEdiV8aX0/gOoaQfaAhQhSQ1EnzwH/AT69GUup J5T8g5nTRD6gfJde1u3/AXQ9Qc8Ku18w8SLCGgtmNORLEmWS+uDPy6ilQ 1jtk5g/EGKPoemzj2wETBPyxJjXwZG/LNqc2THjQMIaO1W6ZSmikyUKck E=; X-IronPort-AV: E=Sophos;i="5.93,258,1654560000"; d="scan'208";a="122554305" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-iad-1e-90d70b14.us-east-1.amazon.com) ([10.25.36.210]) by smtp-border-fw-80006.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Aug 2022 18:13:51 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-iad-1e-90d70b14.us-east-1.amazon.com (Postfix) with ESMTPS id 9AD42C08C3; Tue, 23 Aug 2022 18:13:49 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.249) with Microsoft SMTP Server (TLS) id 15.0.1497.38; Tue, 23 Aug 2022 18:13:48 +0000 Received: from 88665a182662.ant.amazon.com (10.43.162.140) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.12; Tue, 23 Aug 2022 18:13:46 +0000 From: Kuniyuki Iwashima To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v2 bpf] bpf: Fix a data-race around bpf_jit_limit. Date: Tue, 23 Aug 2022 11:12:47 -0700 Message-ID: <20220823181247.90349-1-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.43.162.140] X-ClientProxiedBy: EX13D10UWB003.ant.amazon.com (10.43.161.106) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org While reading bpf_jit_limit, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: ede95a63b5e8 ("bpf: add bpf_jit_limit knob to restrict unpriv allocations") Signed-off-by: Kuniyuki Iwashima --- v2: * Drop other 3 patches (No change for this patch) v1: https://lore.kernel.org/bpf/20220818042339.82992-1-kuniyu@amazon.com/ --- 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 c1e10d088dbb..3d9eb3ae334c 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -971,7 +971,7 @@ pure_initcall(bpf_jit_charge_init); int bpf_jit_charge_modmem(u32 size) { - if (atomic_long_add_return(size, &bpf_jit_current) > bpf_jit_limit) { + if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) { if (!bpf_capable()) { atomic_long_sub(size, &bpf_jit_current); return -EPERM; -- 2.30.2