Commit baff4b7b authored by Trond Myklebust's avatar Trond Myklebust Committed by Zheng Zengkai
Browse files

SUNRPC: Close a race with transport setup and module put 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4IL3P


CVE: NA

--------------------------------

After we've looked up the transport module, we need to ensure it can't
go away until we've finished running the transport setup code.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarLu Wei <luwei32@huawei.com>
Reviewed-by: default avatarWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent a41f60f0

net/sunrpc/xprt.c

+33 −11
Original line number Diff line number Diff line
@@ -158,6 +158,32 @@ xprt_class_release(const struct xprt_class *t) 
	module_put(t->owner);

}



static const struct xprt_class *

xprt_class_find_by_ident_locked(int ident)

{

	const struct xprt_class *t;



	list_for_each_entry(t, &xprt_list, list) {

		if (t->ident != ident)

			continue;

		if (!try_module_get(t->owner))

			continue;

		return t;

	}

	return NULL;

}



static const struct xprt_class *

xprt_class_find_by_ident(int ident)

{

	const struct xprt_class *t;



	spin_lock(&xprt_list_lock);

	t = xprt_class_find_by_ident_locked(ident);

	spin_unlock(&xprt_list_lock);

	return t;

}



static const struct xprt_class *

xprt_class_find_by_netid_locked(const char *netid)

{
@@ -1959,21 +1985,17 @@ static void xprt_init(struct rpc_xprt *xprt, struct net *net) 
struct rpc_xprt *xprt_create_transport(struct xprt_create *args)

{

	struct rpc_xprt	*xprt;

	struct xprt_class *t;

	const struct xprt_class *t;



	spin_lock(&xprt_list_lock);

	list_for_each_entry(t, &xprt_list, list) {

		if (t->ident == args->ident) {

			spin_unlock(&xprt_list_lock);

			goto found;

		}

	}

	spin_unlock(&xprt_list_lock);

	t = xprt_class_find_by_ident(args->ident);

	if (!t) {

		dprintk("RPC: transport (%d) not supported\n", args->ident);

		return ERR_PTR(-EIO);

	}



found:

	xprt = t->setup(args);

	xprt_class_release(t);



	if (IS_ERR(xprt))

		goto out;

	if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT)