linux-kernel - [PATCH 1/2] tracefs: Add missing lockdown check to tracefs_create

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230905182711.692687042@goodmis.org>
Date:   Tue, 05 Sep 2023 14:26:08 -0400
From:   Steven Rostedt <rostedt@...dmis.org>
To:     linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org
Cc:     Masami Hiramatsu <mhiramat@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Ajay Kaher <akaher@...are.com>,
        kernel test robot <oliver.sang@...el.com>,
        Ching-lin Yu <chinglinyu@...gle.com>, stable@...r.kernel.org
Subject: [PATCH 1/2] tracefs: Add missing lockdown check to tracefs_create_dir()

From: "Steven Rostedt (Google)" <rostedt@...dmis.org>

The function tracefs_create_dir() was missing a lockdown check and was
called by the RV code. This gave an inconsistent behavior of this function
returning success while other tracefs functions failed. This caused the
inode being freed by the wrong kmem_cache.

Link: https://lore.kernel.org/all/202309050916.58201dc6-oliver.sang@intel.com/

Cc: stable@...r.kernel.org
Fixes: bf8e602186ec4 ("tracing: Do not create tracefs files if tracefs lockdown is in effect")
Reported-by: kernel test robot <oliver.sang@...el.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@...dmis.org>
---
 fs/tracefs/inode.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index de5b72216b1a..3b8dd938b1c8 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -673,6 +673,9 @@ static struct dentry *__create_dir(const char *name, struct dentry *parent,
  */
 struct dentry *tracefs_create_dir(const char *name, struct dentry *parent)
 {
+	if (security_locked_down(LOCKDOWN_TRACEFS))
+		return NULL;
+
 	return __create_dir(name, parent, &simple_dir_inode_operations);
 }
 
-- 
2.40.1