lkml.org 
[lkml]   [2016]   [Nov]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH 3.16 113/346] module: Invalidate signatures on force-loaded modules
3.16.39-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Ben Hutchings <ben@decadent.org.uk>

commit bca014caaa6130e57f69b5bf527967aa8ee70fdd upstream.

Signing a module should only make it trusted by the specific kernel it
was built for, not anything else. Loading a signed module meant for a
kernel with a different ABI could have interesting effects.
Therefore, treat all signatures as invalid when a module is
force-loaded.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
kernel/module.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2435,13 +2435,18 @@ static inline void kmemleak_load_module(
#endif

#ifdef CONFIG_MODULE_SIG
-static int module_sig_check(struct load_info *info)
+static int module_sig_check(struct load_info *info, int flags)
{
int err = -ENOKEY;
const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
const void *mod = info->hdr;

- if (info->len > markerlen &&
+ /*
+ * Require flags == 0, as a module with version information
+ * removed is no longer the module that was signed
+ */
+ if (flags == 0 &&
+ info->len > markerlen &&
memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
/* We truncate the module to discard the signature */
info->len -= markerlen;
@@ -2463,7 +2468,7 @@ static int module_sig_check(struct load_
return err;
}
#else /* !CONFIG_MODULE_SIG */
-static int module_sig_check(struct load_info *info)
+static int module_sig_check(struct load_info *info, int flags)
{
return 0;
}
@@ -3200,7 +3205,7 @@ static int load_module(struct load_info
long err;
char *after_dashes;

- err = module_sig_check(info);
+ err = module_sig_check(info, flags);
if (err)
goto free_copy;

\
 
 \ /
  Last update: 2016-11-14 04:16    [W:1.481 / U:0.320 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site