From 734f786e959fc536a41f304bbffe9fa9c269b874 Mon Sep 17 00:00:00 2001
From: jiangheng <jiangheng14@huawei.com>
Date: Mon, 19 Jun 2023 15:51:50 +0800
Subject: [PATCH] fix null pointer of sock in udp_recvfrom

---
 src/lstack/api/lstack_wrap.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/lstack/api/lstack_wrap.c b/src/lstack/api/lstack_wrap.c
index 096fcf7..6ee0512 100644
--- a/src/lstack/api/lstack_wrap.c
+++ b/src/lstack/api/lstack_wrap.c
@@ -552,7 +552,7 @@ static inline ssize_t udp_recvfrom(struct lwip_sock *sock, int32_t sockfd, void
 {
     int32_t ret;
 
-    do {
+    while (1) {
         ret = read_stack_data(sockfd, buf, len, flags, addr, addrlen);
         if (ret > 0) {
             return ret;
@@ -561,9 +561,16 @@ static inline ssize_t udp_recvfrom(struct lwip_sock *sock, int32_t sockfd, void
             return -1;
         }
         sock = sock->listen_next;
-        sockfd = sock->conn->socket;
-    } while (sock != NULL);
-    GAZELLE_RETURN(EAGAIN);
+        if (sock != NULL && sock->conn != NULL) {
+            sockfd = sock->conn->socket;
+        } else {
+            if (sock == NULL) {
+                GAZELLE_RETURN(EAGAIN);
+            } else {
+                GAZELLE_RETURN(ENOTCONN);
+            }
+        }
+    }
 }
 
 static inline ssize_t tcp_recvfrom(struct lwip_sock *sock, int32_t sockfd, void *buf, size_t len, int32_t flags,
-- 
2.33.0