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
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
|
From 262e6ae7081df304fc625cf368d5c2cbba2bb991 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Tue, 28 Jul 2020 23:33:33 +0200
Subject: [PATCH] modules: inherit TAINT_PROPRIETARY_MODULE
If a TAINT_PROPRIETARY_MODULE exports symbol, inherit the taint flag
for all modules importing these symbols, and don't allow loading
symbols from TAINT_PROPRIETARY_MODULE modules if the module previously
imported gplonly symbols. Add a anti-circumvention devices so people
don't accidentally get themselves into trouble this way.
Comment from Greg:
"Ah, the proven-to-be-illegal "GPL Condom" defense :)"
[jeyu: pr_info -> pr_err and pr_warn as per discussion]
Link: http://lore.kernel.org/r/20200730162957.GA22469@lst.de
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
---
include/linux/module.h | 1 +
kernel/module.c | 26 ++++++++++++++++++++++++++
2 files changed, 27 insertions(+)
diff --git a/include/linux/module.h b/include/linux/module.h
index 30b0f5fcdb3c3..e30ed5fa33a73 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -389,6 +389,7 @@ struct module {
unsigned int num_gpl_syms;
const struct kernel_symbol *gpl_syms;
const s32 *gpl_crcs;
+ bool using_gplonly_symbols;
#ifdef CONFIG_UNUSED_SYMBOLS
/* unused exported symbols. */
diff --git a/kernel/module.c b/kernel/module.c
index 656f5ff27088f..09bf5a652a47c 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1431,6 +1431,24 @@ static int verify_namespace_is_imported(const struct load_info *info,
return 0;
}
+static bool inherit_taint(struct module *mod, struct module *owner)
+{
+ if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
+ return true;
+
+ if (mod->using_gplonly_symbols) {
+ pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n",
+ mod->name, owner->name);
+ return false;
+ }
+
+ if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
+ pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n",
+ mod->name, owner->name);
+ set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
+ }
+ return true;
+}
/* Resolve a symbol for this module. I.e. if we find one, record usage. */
static const struct kernel_symbol *resolve_symbol(struct module *mod,
@@ -1456,6 +1474,14 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod,
if (!sym)
goto unlock;
+ if (license == GPL_ONLY)
+ mod->using_gplonly_symbols = true;
+
+ if (!inherit_taint(mod, owner)) {
+ sym = NULL;
+ goto getname;
+ }
+
if (!check_version(info, name, mod, crc)) {
sym = ERR_PTR(-EINVAL);
goto getname;
|