From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Daniel Axtens <dja@axtens.net>
Date: Tue, 1 Mar 2022 23:14:15 +1100
Subject: [PATCH] net/http: Do not tear down socket if it's already been torn
 down

It's possible for data->sock to get torn down in tcp error handling.
If we unconditionally tear it down again we will end up doing writes
to an offset of the NULL pointer when we go to tear it down again.

Detect if it has been torn down and don't do it again.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
(cherry picked from commit ec233d3ecf995293304de443579aab5c46c49e85)
---
 grub-core/net/http.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/grub-core/net/http.c b/grub-core/net/http.c
index 7f878b5615..19cb8768e3 100644
--- a/grub-core/net/http.c
+++ b/grub-core/net/http.c
@@ -427,7 +427,7 @@ http_establish (struct grub_file *file, grub_off_t offset, int initial)
       return err;
     }
 
-  for (i = 0; !data->headers_recv && i < 100; i++)
+  for (i = 0; data->sock && !data->headers_recv && i < 100; i++)
     {
       grub_net_tcp_retransmit ();
       grub_net_poll_cards (300, &data->headers_recv);
@@ -435,7 +435,8 @@ http_establish (struct grub_file *file, grub_off_t offset, int initial)
 
   if (!data->headers_recv)
     {
-      grub_net_tcp_close (data->sock, GRUB_NET_TCP_ABORT);
+      if (data->sock)
+        grub_net_tcp_close (data->sock, GRUB_NET_TCP_ABORT);
       if (data->err)
 	{
 	  char *str = data->errmsg;