kprobes: Make list and blacklist root user read only

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@linux.ibm.com>
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Howells <dhowells@redhat.com>
Cc: David S . Miller <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jon Medhurst <tixy@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tobin C . Harding <me@tobin.cc>
Cc: Will Deacon <will.deacon@arm.com>
Cc: acme@kernel.org
Cc: akpm@linux-foundation.org
Cc: brueckner@linux.vnet.ibm.com
Cc: linux-arch@vger.kernel.org
Cc: rostedt@goodmis.org
Cc: schwidefsky@de.ibm.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/lkml/152491890171.9916.5183693615601334087.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 536ab451e96d643a0eaa9cc5d3bc149501df18d4..898ee56d4f489f09d00e57a35d666902785e1d4a 100644 (file)
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2509,7 +2509,7 @@ static int __init debugfs_kprobe_init(void)
        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;
@@ -2519,7 +2519,7 @@ static int __init debugfs_kprobe_init(void)
        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;