nfsd: Fix svc_xprt refcnt leak when setup callback client failed

nfsd4_process_cb_update() invokes svc_xprt_get(), which increases the refcount of the "c->cn_xprt". The reference counting issue happens in one exception handling path of nfsd4_process_cb_update(). When setup callback client failed, the function forgets to decrease the refcnt increased by svc_xprt_get(), causing a refcnt leak. Fix this issue by calling svc_xprt_put() when setup callback client failed. Signed-off-by: Xiyu Yang <[email protected]> Signed-off-by: Xin Tan <[email protected]> Signed-off-by: J. Bruce Fields <[email protected]>
ambv · May 28, 2020 · a4abc6b · a4abc6b
1 parent 24c5efe
commit a4abc6b
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
@@ -1306,6 +1306,8 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
 	err = setup_callback_client(clp, &conn, ses);
 	if (err) {
 		nfsd4_mark_cb_down(clp, err);
+		if (c)
+			svc_xprt_put(c->cn_xprt);
 		return;
 	}
 }