From nobody Wed Sep 3 06:26:36 2025 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 91614C38A2D for ; Mon, 24 Oct 2022 12:38:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231728AbiJXMig (ORCPT ); Mon, 24 Oct 2022 08:38:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43920 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233888AbiJXM2e (ORCPT ); Mon, 24 Oct 2022 08:28:34 -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 2E93386FBB; Mon, 24 Oct 2022 05:02:18 -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 64C12B81150; Mon, 24 Oct 2022 11:58:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BAF06C433D6; Mon, 24 Oct 2022 11:58:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666612709; bh=KXBQ6MdwJlojy74YROK74a4S4l8XmysUHJstxMTskFQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sOMUvPi7gmYmooroz3cYA+glwU2WBlIVqGb5BM2bdUbdIyEWTkw5T8hJXOebmrHPr 4a5kWokoGWJKP9zChRZNuou0aMjigxDgWTRUVHe+Ev5fyBn/3dtZmrvTTD0Jl7b368 QI2zItdFX31ytmr7rgF1gN6rbjAkdTLbwSCwXTsI= 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 4.19 082/229] bpf: Ensure correct locking around vulnerable function find_vpid() Date: Mon, 24 Oct 2022 13:30:01 +0200 Message-Id: <20221024113001.724483738@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024112959.085534368@linuxfoundation.org> References: <20221024112959.085534368@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 e940c1f65938..02e5bdb82a9a 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2325,7 +2325,9 @@ static int bpf_task_fd_query(const union bpf_attr *at= tr, if (attr->task_fd_query.flags !=3D 0) return -EINVAL; =20 + rcu_read_lock(); task =3D get_pid_task(find_vpid(pid), PIDTYPE_PID); + rcu_read_unlock(); if (!task) return -ENOENT; =20 --=20 2.35.1