linux-kernel - [PATCH 7/7] modules: inherit TAINT_PROPRIETARY

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: <20200729062711.13016-8-hch@lst.de>
Date:   Wed, 29 Jul 2020 08:27:11 +0200
From:   Christoph Hellwig <hch@....de>
To:     Jessica Yu <jeyu@...nel.org>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-kernel@...r.kernel.org (open list)
Subject: [PATCH 7/7] modules: inherit TAINT_PROPRIETARY_MODULE

If a TAINT_PROPRIETARY_MODULE exports symbol, inherit the tain 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.

Signed-off-by: Christoph Hellwig <hch@....de>
---
 include/linux/module.h |  1 +
 kernel/module.c        | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/include/linux/module.h b/include/linux/module.h
index c9bc3412ae4465..d49e033563dadf 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 a907bc57d343f9..eb6ab2f4b81aaa 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1456,6 +1456,18 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod,
 	if (!sym)
 		goto unlock;
 
+	if (licence == GPL_ONLY)
+		mod->using_gplonly_symbols = true;
+
+	if (owner && test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints)) {
+		if (mod->using_gplonly_symbols) {
+			sym = NULL;
+			goto getname;
+		}
+		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+				 LOCKDEP_NOW_UNRELIABLE);
+	}
+
 	if (!check_version(info, name, mod, crc)) {
 		sym = ERR_PTR(-EINVAL);
 		goto getname;
-- 
2.27.0