From patchwork Tue Dec 1 08:53:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 336889 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=-18.7 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, URIBL_BLOCKED, 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 A79CDC64E8A for ; Tue, 1 Dec 2020 08:59:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B3F622242 for ; Tue, 1 Dec 2020 08:59:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="w5pkbvq+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388103AbgLAI7P (ORCPT ); Tue, 1 Dec 2020 03:59:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:34902 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388094AbgLAI7O (ORCPT ); Tue, 1 Dec 2020 03:59:14 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 11B2021D7F; Tue, 1 Dec 2020 08:58:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606813113; bh=S2hOqoDlK5MPvLUKCjduU+DTQ9JNcGnXtpFB+KJ6Wfc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=w5pkbvq+JYrJiGw4+Ky/JdhQ0/jTg6A1LjHLU7i3PnaR27lbXJVKPdqlUrN3gwK1h oCO/904NsdkIUH/ouXaJL3WdgaIiR8vYBPBwV5+w6F9HpYPUR+B6u60tzGKmN+zRE9 mKq4DegdnZJkKKCeJ9aGx3qncYcPdca7wKHnlFIg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jens Axboe , Sasha Levin Subject: [PATCH 4.14 20/50] proc: dont allow async path resolution of /proc/self components Date: Tue, 1 Dec 2020 09:53:19 +0100 Message-Id: <20201201084647.650735416@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201201084644.803812112@linuxfoundation.org> References: <20201201084644.803812112@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jens Axboe [ Upstream commit 8d4c3e76e3be11a64df95ddee52e99092d42fc19 ] If this is attempted by a kthread, then return -EOPNOTSUPP as we don't currently support that. Once we can get task_pid_ptr() doing the right thing, then this can go away again. Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- fs/proc/self.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/proc/self.c b/fs/proc/self.c index 398cdf9a9f0c6..eba167e1700ef 100644 --- a/fs/proc/self.c +++ b/fs/proc/self.c @@ -15,6 +15,13 @@ static const char *proc_self_get_link(struct dentry *dentry, pid_t tgid = task_tgid_nr_ns(current, ns); char *name; + /* + * Not currently supported. Once we can inherit all of struct pid, + * we can allow this. + */ + if (current->flags & PF_KTHREAD) + return ERR_PTR(-EOPNOTSUPP); + if (!tgid) return ERR_PTR(-ENOENT); /* 11 for max length of signed int in decimal + NULL term */