From patchwork Tue Dec 1 08:53:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 335736 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=unavailable 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 8C53FC64E7B for ; Tue, 1 Dec 2020 09:31:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A3CF2085B for ; Tue, 1 Dec 2020 09:31:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="SKsqCa/j" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729077AbgLAIzT (ORCPT ); Tue, 1 Dec 2020 03:55:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:57764 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729074AbgLAIzS (ORCPT ); Tue, 1 Dec 2020 03:55:18 -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 7FBEF22244; Tue, 1 Dec 2020 08:54:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606812875; bh=p56lrdY5ZhqQEjuwgoXjBLvEgDUWDJPeSLi/zSLGKIo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SKsqCa/jIQMHebZGzKiyqRj4pX5Hjzv5r//G27yUjlvgvedcERPV4SiOc/wm6RwVw 4FINx0SoGVyNHhQc5c+F/IBaoVfFt7vofMLLUf3cBmoPVCVixAFvJZ76/WBqSZQwwm 5nnzB4SSCHHougyZVAvyYwDn7Q22aOkZzJRxCz1A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jens Axboe , Sasha Levin Subject: [PATCH 4.4 08/24] proc: dont allow async path resolution of /proc/self components Date: Tue, 1 Dec 2020 09:53:14 +0100 Message-Id: <20201201084638.166527632@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201201084637.754785180@linuxfoundation.org> References: <20201201084637.754785180@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 2dcc2558b3aa7..dffbe533d53fc 100644 --- a/fs/proc/self.c +++ b/fs/proc/self.c @@ -24,6 +24,13 @@ static const char *proc_self_follow_link(struct dentry *dentry, void **cookie) 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 */