Merge branch 'for-2.6.37' of git://linux-nfs.org/~bfields/linux

* 'for-2.6.37' of git://linux-nfs.org/~bfields/linux:
  nfsd: Fix possible BUG_ON firing in set_change_info
  sunrpc: prevent use-after-free on clearing XPT_BUSY

1 files changed, 8 insertions, 1 deletions

diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index ea2ff78dcf7b..3f2c5559ca1a 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -212,6 +212,7 @@ int svc_create_xprt(struct svc_serv *serv, const char *xprt_name,
         spin_lock(&svc_xprt_class_lock);
         list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
                 struct svc_xprt *newxprt;
+                unsigned short newport;
 
                 if (strcmp(xprt_name, xcl->xcl_name))
                         continue;
@@ -230,8 +231,9 @@ int svc_create_xprt(struct svc_serv *serv, const char *xprt_name,
                 spin_lock_bh(&serv->sv_lock);
                 list_add(&newxprt->xpt_list, &serv->sv_permsocks);
                 spin_unlock_bh(&serv->sv_lock);
+                newport = svc_xprt_local_port(newxprt);
                 clear_bit(XPT_BUSY, &newxprt->xpt_flags);
-                return svc_xprt_local_port(newxprt);
+                return newport;
         }
  err:
         spin_unlock(&svc_xprt_class_lock);
@@ -425,8 +427,13 @@ void svc_xprt_received(struct svc_xprt *xprt)
 {
         BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags));
         xprt->xpt_pool = NULL;
+        /* As soon as we clear busy, the xprt could be closed and
+         * 'put', so we need a reference to call svc_xprt_enqueue with:
+         */
+        svc_xprt_get(xprt);
         clear_bit(XPT_BUSY, &xprt->xpt_flags);
         svc_xprt_enqueue(xprt);
+        svc_xprt_put(xprt);
 }
 EXPORT_SYMBOL_GPL(svc_xprt_received);