Commit bf8e6021 authored Oct 11, 2019 by Steven Rostedt (VMware)

tracing: Do not create tracefs files if tracefs lockdown is in effect

If on boot up, lockdown is activated for tracefs, don't even bother creating
the files. This can also prevent instances from being created if lockdown is
in effect.

Link: http://lkml.kernel.org/r/CAHk-=whC6Ji=fWnjh2+eS4b15TnbsS4VPVtvBOwCy1jjEG_JHQ@mail.gmail.com

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

parent 17911ff3

fs/tracefs/inode.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -16,6 +16,7 @@
		#include <linux/namei.h>
		#include <linux/tracefs.h>
		#include <linux/fsnotify.h>
		#include <linux/security.h>
		#include <linux/seq_file.h>
		#include <linux/parser.h>
		#include <linux/magic.h>
		@@ -390,6 +391,9 @@ struct dentry tracefs_create_file(const char name, umode_t mode,
		struct dentry *dentry;
		struct inode *inode;

		if (security_locked_down(LOCKDOWN_TRACEFS))
		return NULL;

		if (!(mode & S_IFMT))
		mode \|= S_IFREG;
		BUG_ON(!S_ISREG(mode));