diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index e4ffdec0d8..544f5b662f 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -2127,6 +2127,9 @@ static abi_long do_setsockopt(int sockfd, int level, int optname,
                 return -TARGET_EINVAL;
 
             ip_mreq_source = lock_user(VERIFY_READ, optval_addr, optlen, 1);
+            if (!ip_mreq_source) {
+                return -TARGET_EFAULT;
+            }
             ret = get_errno(setsockopt(sockfd, level, optname, ip_mreq_source, optlen));
             unlock_user (ip_mreq_source, optval_addr, 0);
             break;