livepatch: Improve error handling in klp_disable_func()

In case of func->state or func->old_addr not having expected values,
we'd rather bail out immediately from klp_disable_func().

This can't really happen with the current codebase, but fix this
anyway in the sake of robustness.

[jkosina@suse.com: reworded the changelog a bit]
Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index c40ebcca0495..6e5344112419 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -348,8 +348,10 @@ static void klp_disable_func(struct klp_func *func)
 {
         struct klp_ops *ops;
 
-        WARN_ON(func->state != KLP_ENABLED);
-        WARN_ON(!func->old_addr);
+        if (WARN_ON(func->state != KLP_ENABLED))
+                return;
+        if (WARN_ON(!func->old_addr))
+                return;
 
         ops = klp_find_ops(func->old_addr);
         if (WARN_ON(!ops))