[PATCH v4 01/11] livepatch: Disallow vmlinux.ko

Josh Poimboeuf
2020-04-29T15:25:21Z

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>
---
kernel/livepatch/core.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index c3512e7e0801..40cfac8156fd 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()
--
2.21.1