From: Stefan Eissing <stefan@eissing.org>
Date: Mon, 6 Oct 2025 12:08:07 +0000 (+0200)
Subject: socks: handle premature close
X-Git-Tag: rc-8_17_0-1~84
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=089afd78cb5897adf5a42d8ccff01d7c32c8fada;p=thirdparty%2Fcurl.git

socks: handle premature close

When expecting to receive a number of bytes during socks connect,
treat an early connection close as error.

Reported-by: Joshua Rogers
Closes #18883
---

diff --git a/lib/socks.c b/lib/socks.c
index ba7b28d04a..e7e545442a 100644
--- a/lib/socks.c
+++ b/lib/socks.c
@@ -254,8 +254,14 @@ static CURLproxycode socks_recv(struct socks_state *sx,
             curl_easy_strerror(result));
       return CURLPX_RECV_CONNECT;
     }
-    else if(!nread) /* EOF */
+    else if(!nread) { /* EOF */
+      if(Curl_bufq_len(&sx->iobuf) < min_bytes) {
+        failf(data, "Failed to receive SOCKS response, "
+              "proxy closed connection");
+        return CURLPX_RECV_CONNECT;
+      }
       break;
+    }
   }
   *done = TRUE;
   return CURLPX_OK;