From 4f48795b6154852d07d971e402c35ecc460ddcb6 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Mon, 10 Nov 2014 09:26:29 +1030 Subject: [PATCH] module: Wait for RCU synchronizing before releasing a module Wait for RCU synchronizing on failure path of module loading before releasing struct module, because the memory of mod->list can still be accessed by list walkers (e.g. kallsyms). Signed-off-by: Masami Hiramatsu Signed-off-by: Rusty Russell --- kernel/module.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/module.c b/kernel/module.c index 88cec1ddb1e3..331b03f6b411 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3326,6 +3326,8 @@ static int load_module(struct load_info *info, const char __user *uargs, /* Unlink carefully: kallsyms could be walking list. */ list_del_rcu(&mod->list); wake_up_all(&module_wq); + /* Wait for RCU synchronizing before releasing mod->list. */ + synchronize_rcu(); mutex_unlock(&module_mutex); free_module: module_deallocate(mod, info); -- 2.20.1