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 0E56CC00140 for ; Thu, 18 Aug 2022 04:25:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243283AbiHREZD (ORCPT ); Thu, 18 Aug 2022 00:25:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243344AbiHREY6 (ORCPT ); Thu, 18 Aug 2022 00:24:58 -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 3000C5A2F1; Wed, 17 Aug 2022 21:24:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1660796695; x=1692332695; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Pt7raKiGCAdlvrA1Au6FchloUhmX4Kpo9GZzRuJY0UU=; b=g+Leu9A1sbXPAeNNXvhqieApeja9bLjHhWqnivr3SjSPW1ESiaUGO3Fe bekN3WFSiwci4JM4PH/7ceyCKsKbObMzyrR1ydsiq34qJX91vyhPKZhU7 z9NQUzKdiEUpJbODshCpHH+nl0ZQSEr24oq+nueal0TYa2OKI18IKVvX7 M=; X-IronPort-AV: E=Sophos;i="5.93,245,1654560000"; d="scan'208";a="120461433" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-pdx-2a-1801e169.us-west-2.amazon.com) ([10.25.36.210]) by smtp-border-fw-80006.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Aug 2022 04:24:54 +0000 Received: from EX13MTAUWB001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan3.pdx.amazon.com [10.236.137.198]) by email-inbound-relay-pdx-2a-1801e169.us-west-2.amazon.com (Postfix) with ESMTPS id 016ACC0AC6; Thu, 18 Aug 2022 04:24:52 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.38; Thu, 18 Aug 2022 04:24:51 +0000 Received: from 88665a182662.ant.amazon.com.com (10.43.162.158) 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; Thu, 18 Aug 2022 04:24:49 +0000 From: Kuniyuki Iwashima To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v1 bpf 4/4] bpf: Fix a data-race around bpf_jit_limit. Date: Wed, 17 Aug 2022 21:23:39 -0700 Message-ID: <20220818042339.82992-5-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220818042339.82992-1-kuniyu@amazon.com> References: <20220818042339.82992-1-kuniyu@amazon.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.43.162.158] X-ClientProxiedBy: EX13D43UWC002.ant.amazon.com (10.43.162.172) 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 --- 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