[PATCH 4.9 096/107] kprobes: Make list and blacklist root user read only

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>

commit f2a3ab36077222437b4826fc76111caa14562b7c upstream.

Since the blacklist and list files on debugfs indicates
a sensitive address information to reader, it should be
restricted to the root user.

Suggested-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
Suggested-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: David S . Miller <davem@xxxxxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Jon Medhurst <tixy@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Tobin C . Harding <me@xxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: acme@xxxxxxxxxx
Cc: akpm@xxxxxxxxxxxxxxxxxxxx
Cc: brueckner@xxxxxxxxxxxxxxxxxx
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: rostedt@xxxxxxxxxxx
Cc: schwidefsky@xxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/lkml/152491890171.9916.5183693615601334087.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 kernel/kprobes.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2441,7 +2441,7 @@ static int __init debugfs_kprobe_init(vo
 	if (!dir)
 		return -ENOMEM;
 
-	file = debugfs_create_file("list", 0444, dir, NULL,
+	file = debugfs_create_file("list", 0400, dir, NULL,
 				&debugfs_kprobes_operations);
 	if (!file)
 		goto error;
@@ -2451,7 +2451,7 @@ static int __init debugfs_kprobe_init(vo
 	if (!file)
 		goto error;
 
-	file = debugfs_create_file("blacklist", 0444, dir, NULL,
+	file = debugfs_create_file("blacklist", 0400, dir, NULL,
 				&debugfs_kprobe_blacklist_ops);
 	if (!file)
 		goto error;