linux-kernel - [RFC v2 4/7] modsig: add integrity_module

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <68a6f647ca1d4429d6b781b6cfeed9c93a346c14.1345055639.git.dmitry.kasatkin@intel.com>
Date:	Wed, 15 Aug 2012 21:43:09 +0300
From:	Dmitry Kasatkin <dmitry.kasatkin@...el.com>
To:	zohar@...ux.vnet.ibm.com, jmorris@...ei.org, rusty@...tcorp.com.au,
	dhowells@...hat.com, linux-security-module@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [RFC v2 4/7] modsig: add integrity_module_check hook

IMA measures/appraises modules when modprobe or insmod opens and read them.
Unfortunately, there are no guarantees between what is read by userspace and
what is passed to the kernel via load_module system call. This patch adds a
hook called integrity_module_check() to verify the integrity of the module
being loaded.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@...el.com>
---
 include/linux/integrity.h |   10 ++++++++++
 kernel/module.c           |    9 +++++++++
 2 files changed, 19 insertions(+)

diff --git a/include/linux/integrity.h b/include/linux/integrity.h
index 66c5fe9..a80ec06 100644
--- a/include/linux/integrity.h
+++ b/include/linux/integrity.h
@@ -37,4 +37,14 @@ static inline void integrity_inode_free(struct inode *inode)
 	return;
 }
 #endif /* CONFIG_INTEGRITY_H */
+
+#ifdef CONFIG_INTEGRITY_MODULES
+int integrity_module_check(const void *hdr, const unsigned long len);
+#else
+static inline int integrity_module_check(const void *buf, unsigned long len)
+{
+	return 0;
+}
+#endif
+
 #endif /* _LINUX_INTEGRITY_H */
diff --git a/kernel/module.c b/kernel/module.c
index 4edbd9c..791da47 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -58,6 +58,7 @@
 #include <linux/jump_label.h>
 #include <linux/pfn.h>
 #include <linux/bsearch.h>
+#include <linux/integrity.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/module.h>
@@ -2437,6 +2438,14 @@ static int copy_and_check(struct load_info *info,
 
 	info->hdr = hdr;
 	info->len = len;
+
+	err = integrity_module_check(hdr, len);
+	if (err < 0)
+		goto free_hdr;
+
+	/* cut signature tail */
+	info->len = err;
+
 	return 0;
 
 free_hdr:
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/