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 D291EFA3742 for ; Mon, 24 Oct 2022 13:32:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231932AbiJXNcW (ORCPT ); Mon, 24 Oct 2022 09:32:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49090 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235975AbiJXN3R (ORCPT ); Mon, 24 Oct 2022 09:29:17 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AE49E12A9A; Mon, 24 Oct 2022 05:32:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id F34C5B81212; Mon, 24 Oct 2022 12:07:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E0D6C4314E; Mon, 24 Oct 2022 12:07:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666613271; bh=eu3dHn2Lu/ALN7PdPni6DW2q/Erc6p8YdVQGodhk4OA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WqGN/J9aNfxZggqej0WeCfHpFcT0YIFJ6Tg4/Ck09XW0zlt57UVyJWu1wmTHubJt9 GDRECsKBVPKeLr0/JDgCUu1yP3lL1h/WHoDPTdSyS7yjYXMCEm2ynaGZsvGUvY3GIf bJTvK+t4IfyVP1fc+pMOvd+tOxW9xafjVWMo54NU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lee Jones , Daniel Borkmann , Yonghong Song , Sasha Levin Subject: [PATCH 5.4 074/255] bpf: Ensure correct locking around vulnerable function find_vpid() Date: Mon, 24 Oct 2022 13:29:44 +0200 Message-Id: <20221024113004.972494500@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024113002.471093005@linuxfoundation.org> References: <20221024113002.471093005@linuxfoundation.org> User-Agent: quilt/0.67 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: Lee Jones [ Upstream commit 83c10cc362d91c0d8d25e60779ee52fdbbf3894d ] The documentation for find_vpid() clearly states: "Must be called with the tasklist_lock or rcu_read_lock() held." Presently we do neither for find_vpid() instance in bpf_task_fd_query(). Add proper rcu_read_lock/unlock() to fix the issue. Fixes: 41bdc4b40ed6f ("bpf: introduce bpf subcommand BPF_TASK_FD_QUERY") Signed-off-by: Lee Jones Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20220912133855.1218900-1-lee@kernel.org Signed-off-by: Sasha Levin --- kernel/bpf/syscall.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 9ebdcdaa5f16..de788761b708 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2787,7 +2787,9 @@ static int bpf_task_fd_query(const union bpf_attr *attr, if (attr->task_fd_query.flags != 0) return -EINVAL; + rcu_read_lock(); task = get_pid_task(find_vpid(pid), PIDTYPE_PID); + rcu_read_unlock(); if (!task) return -ENOENT; -- 2.35.1