This is a note to let you know that I've just added the patch titled
tracefs: Add missing lockdown check to tracefs_create_dir()
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tracefs-add-missing-lockdown-check-to-tracefs_create_dir.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 51aab5ffceb43e05119eb059048fd75765d2bc21 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
Date: Tue, 5 Sep 2023 14:26:08 -0400
Subject: tracefs: Add missing lockdown check to tracefs_create_dir()
From: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
commit 51aab5ffceb43e05119eb059048fd75765d2bc21 upstream.
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@xxxxxxxxxxx
Link: https://lore.kernel.org/all/202309050916.58201dc6-oliver.sang@xxxxxxxxx/
Cc: stable@xxxxxxxxxxxxxxx
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Ajay Kaher <akaher@xxxxxxxxxx>
Cc: Ching-lin Yu <chinglinyu@xxxxxxxxxx>
Fixes: bf8e602186ec4 ("tracing: Do not create tracefs files if tracefs lockdown is in effect")
Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/tracefs/inode.c | 3 +++
1 file changed, 3 insertions(+)
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -556,6 +556,9 @@ static struct dentry *__create_dir(const
*/
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);
}
Patches currently in stable-queue which might be from rostedt@xxxxxxxxxxx are
queue-5.15/tracefs-add-missing-lockdown-check-to-tracefs_create_dir.patch
queue-5.15/selftests-tracing-fix-to-unmount-tracefs-for-recover.patch
queue-5.15/tracing-have-current_trace-inc-the-trace-array-ref-count.patch
queue-5.15/tracing-have-option-files-inc-the-trace-array-ref-count.patch
queue-5.15/tracing-have-tracing_max_latency-inc-the-trace-array-ref-count.patch
