From 51aab5ffceb43e05119eb059048fd75765d2bc21 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Tue, 5 Sep 2023 14:26:08 -0400 Subject: [PATCH] tracefs: Add missing lockdown check to tracefs_create_dir() 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://lkml.kernel.org/r/20230905182711.692687042@goodmis.org Link: https://lore.kernel.org/all/202309050916.58201dc6-oliver.sang@intel.com/ Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Andrew Morton Cc: Ajay Kaher Cc: Ching-lin Yu Fixes: bf8e602186ec4 ("tracing: Do not create tracefs files if tracefs lockdown is in effect") Reported-by: kernel test robot Signed-off-by: Steven Rostedt (Google) --- 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); }