From: Josh Poimboeuf <jpoimboe@redhat.com>
Date: Wed, 29 Apr 2020 15:24:43 +0000 (-0500)
Subject: livepatch: Disallow vmlinux.ko
X-Git-Tag: v5.8-rc1~149^2~14
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=dcf550e52f567cb7a421169d2522869f9188aca5;p=thirdparty%2Flinux.git

livepatch: Disallow vmlinux.ko

This is purely a theoretical issue, but if there were a module named
vmlinux.ko, the livepatch relocation code wouldn't be able to
distinguish between vmlinux-specific and vmlinux.o-specific KLP
relocations.

If CONFIG_LIVEPATCH is enabled, don't allow a module named vmlinux.ko.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
---

diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index c3512e7e08012..40cfac8156fd3 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -1139,6 +1139,11 @@ int klp_module_coming(struct module *mod)
 	if (WARN_ON(mod->state != MODULE_STATE_COMING))
 		return -EINVAL;
 
+	if (!strcmp(mod->name, "vmlinux")) {
+		pr_err("vmlinux.ko: invalid module name");
+		return -EINVAL;
+	}
+
 	mutex_lock(&klp_mutex);
 	/*
 	 * Each module has to know that klp_module_coming()