[PATCH RFC v3 3/4] module: update state and release reference under lock

[Daniel Gomez via B4 Relay]

From: Daniel Gomez <da.gomez@xxxxxxxxxxx>

Ensure the module state change and reference drop operations are
performed within module_mutex to prevent potential race conditions in
the failure path.

Signed-off-by: Daniel Gomez <da.gomez@xxxxxxxxxxx>
---
 kernel/module/main.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/module/main.c b/kernel/module/main.c
index 35a50ded64a6..2b45a6efa0a9 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2994,10 +2994,12 @@ static noinline int do_init_module(struct module *mod)
 fail_free_freeinit:
 	kfree(freeinit);
 fail:
+	mutex_lock(&module_mutex);
 	/* Try to protect us from buggy refcounters. */
 	mod->state = MODULE_STATE_GOING;
-	synchronize_rcu();
 	module_put(mod);
+	mutex_unlock(&module_mutex);
+	synchronize_rcu();
 	blocking_notifier_call_chain(&module_notify_list,
 				     MODULE_STATE_GOING, mod);
 	klp_module_going(mod);

-- 
2.39.2