From patchwork Fri Feb 25 16:52:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 546169 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 19FB3C43217 for ; Fri, 25 Feb 2022 16:52:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242828AbiBYQxS (ORCPT ); Fri, 25 Feb 2022 11:53:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37544 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243224AbiBYQwy (ORCPT ); Fri, 25 Feb 2022 11:52:54 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D590C22322B; Fri, 25 Feb 2022 08:52:22 -0800 (PST) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 7D81661D07; Fri, 25 Feb 2022 16:52:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA770C340F4; Fri, 25 Feb 2022 16:52:20 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.95) (envelope-from ) id 1nNdpL-00B8N1-TD; Fri, 25 Feb 2022 11:52:19 -0500 Message-ID: <20220225165219.737025658@goodmis.org> User-Agent: quilt/0.66 Date: Fri, 25 Feb 2022 11:52:00 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , stable@vger.kernel.org, Al Viro Subject: [for-linus][PATCH 09/13] tracefs: Set the group ownership in apply_options() not parse_options() References: <20220225165151.824659113@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: "Steven Rostedt (Google)" Al Viro brought it to my attention that the dentries may not be filled when the parse_options() is called, causing the call to set_gid() to possibly crash. It should only be called if parse_options() succeeds totally anyway. He suggested the logical place to do the update is in apply_options(). Cc: stable@vger.kernel.org Reported-by: Al Viro Fixes: 48b27b6b5191 ("tracefs: Set all files to the same group ownership as the mount option") Signed-off-by: Steven Rostedt (Google) --- fs/tracefs/inode.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c index bafc02bf8220..3638d330ff5a 100644 --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -264,7 +264,6 @@ static int tracefs_parse_options(char *data, struct tracefs_mount_opts *opts) if (!gid_valid(gid)) return -EINVAL; opts->gid = gid; - set_gid(tracefs_mount->mnt_root, gid); break; case Opt_mode: if (match_octal(&args[0], &option)) @@ -293,6 +292,9 @@ static int tracefs_apply_options(struct super_block *sb) inode->i_uid = opts->uid; inode->i_gid = opts->gid; + if (tracefs_mount && tracefs_mount->mnt_root) + set_gid(tracefs_mount->mnt_root, opts->gid); + return 0; }