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 X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F386EC432C3 for ; Mon, 28 Dec 2020 15:43:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C765B207C8 for ; Mon, 28 Dec 2020 15:43:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2633016AbgL1Pm6 (ORCPT ); Mon, 28 Dec 2020 10:42:58 -0500 Received: from mail.kernel.org ([198.145.29.99]:48260 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405648AbgL1Nr2 (ORCPT ); Mon, 28 Dec 2020 08:47:28 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1F3692072C; Mon, 28 Dec 2020 13:47:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609163232; bh=gP0Ok61iEpEARPAp79nD/b4yoKps0F5dI7IcnTs5RR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A5iJwtbQ2XMQ+57DNeKh0SOmYef+aAPEtSEiPZohjq4ajd5D87Cg3XSUp/wux3P/t mgeJD1nl2/p8tOQTRg1BUN3PtkgKA6K8+Tk13187giR3LtF+4/HXckNle0fOU67Mb0 Oqlt70kWRxyGcxKiiX/v6hQ9Wm9yDYxocxMnKCIo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrii Nakryiko , Alexei Starovoitov , Martin KaFai Lau , Sasha Levin Subject: [PATCH 5.4 216/453] bpf: Fix bpf_put_raw_tracepoint()s use of __module_address() Date: Mon, 28 Dec 2020 13:47:32 +0100 Message-Id: <20201228124947.611645842@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124937.240114599@linuxfoundation.org> References: <20201228124937.240114599@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: stable@vger.kernel.org From: Andrii Nakryiko [ Upstream commit 12cc126df82c96c89706aa207ad27c56f219047c ] __module_address() needs to be called with preemption disabled or with module_mutex taken. preempt_disable() is enough for read-only uses, which is what this fix does. Also, module_put() does internal check for NULL, so drop it as well. Fixes: a38d1107f937 ("bpf: support raw tracepoints in modules") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20201203204634.1325171-2-andrii@kernel.org Signed-off-by: Sasha Levin --- kernel/trace/bpf_trace.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 2372b861f2cfa..74c1db7178cff 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1320,10 +1320,12 @@ struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) { - struct module *mod = __module_address((unsigned long)btp); + struct module *mod; - if (mod) - module_put(mod); + preempt_disable(); + mod = __module_address((unsigned long)btp); + module_put(mod); + preempt_enable(); } static __always_inline -- 2.27.0