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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 0E13DC64E75 for ; Wed, 25 Nov 2020 15:39:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF0C2221FE for ; Wed, 25 Nov 2020 15:39:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="cS3HRlE9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731457AbgKYPiu (ORCPT ); Wed, 25 Nov 2020 10:38:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:56878 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731378AbgKYPiQ (ORCPT ); Wed, 25 Nov 2020 10:38:16 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4F48021D91; Wed, 25 Nov 2020 15:38:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606318696; bh=p56lrdY5ZhqQEjuwgoXjBLvEgDUWDJPeSLi/zSLGKIo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cS3HRlE9oRbCP+T/0fKjGoTduqXCpo5zL6X6RH45oriuRabyrinbhU4cMwoLlliLO CAp+U6Bpv2Nz2GYmPSome2reOon7tOkijUuhLF5l2ok3474bfLsUyMKC8ft+ZPswTq f3wWMA66d6sUOd4y9YAurquvZoj1wG/VOb065GF0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jens Axboe , Sasha Levin , linux-fsdevel@vger.kernel.org Subject: [PATCH AUTOSEL 4.4 5/8] proc: don't allow async path resolution of /proc/self components Date: Wed, 25 Nov 2020 10:38:05 -0500 Message-Id: <20201125153808.811104-5-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201125153808.811104-1-sashal@kernel.org> References: <20201125153808.811104-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@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 */ -- 2.27.0