blob: 2dd3fa020f78f1de6368b7e48b5806249227097d (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
From: David Howells <dhowells@redhat.com>
Date: Wed, 8 Nov 2017 15:11:36 +0000
Subject: [24/29] debugfs: Disallow use of debugfs files when the kernel is
locked down
Origin: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/commit?id=118cc5e1c27e1a75640cf2379c1299e12791063e
Disallow opening of debugfs files when the kernel is locked down as various
drivers give raw access to hardware through debugfs.
Accesses to tracefs should use /sys/kernel/tracing/ rather than
/sys/kernel/debug/tracing/. Possibly a symlink should be emplaced.
Normal device interaction should be done through configfs or a miscdev, not
debugfs.
Note that this makes it unnecessary to specifically lock down show_dsts(),
show_devs() and show_call() in the asus-wmi driver.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Andy Shevchenko <andy.shevchenko@gmail.com>
cc: acpi4asus-user@lists.sourceforge.net
cc: platform-driver-x86@vger.kernel.org
cc: Matthew Garrett <matthew.garrett@nebula.com>
cc: Thomas Gleixner <tglx@linutronix.de>
[bwh: Forward-ported to 4.15]
---
fs/debugfs/file.c | 6 ++++++
1 file changed, 6 insertions(+)
Index: linux/fs/debugfs/file.c
===================================================================
--- linux.orig/fs/debugfs/file.c
+++ linux/fs/debugfs/file.c
@@ -142,6 +142,9 @@ static int open_proxy_open(struct inode
const struct file_operations *real_fops = NULL;
int r;
+ if (kernel_is_locked_down("debugfs"))
+ return -EPERM;
+
r = debugfs_file_get(dentry);
if (r)
return r == -EIO ? -ENOENT : r;
@@ -267,6 +270,9 @@ static int full_proxy_open(struct inode
struct file_operations *proxy_fops = NULL;
int r;
+ if (kernel_is_locked_down("debugfs"))
+ return -EPERM;
+
r = debugfs_file_get(dentry);
if (r)
return r == -EIO ? -ENOENT : r;
|
