socks_gssapi: replace `gss_release_buffer()` with curl free for buffers owned by...

Before this patch, this code used to call `gss_release_buffer()` on
objects with buffers allocated via curl's allocator.
`gss_release_buffer()` calls system (or Win32) free on these buffers,
which may mismatch with curl's allocator. To fix it, align these calls
with the pattern used in vauth modules, by replacing
`gss_release_buffer()` with curl free to release the buffers.

Use `Curl_safefree()` to set the freed pointer to NULL, as
`gss_release_buffer()` did.

Also: use object length var when allocating.

Reported-by: Joshua Rogers
Closes #19018

diff --git a/lib/socks_gssapi.c b/lib/socks_gssapi.c
index 5ad93441a830384535e554e43740a414d751c38a..9b0b31792bc11838b2549258101df8aad656c7f5 100644 (file)
--- a/lib/socks_gssapi.c
+++ b/lib/socks_gssapi.c
@@ -166,7 +166,7 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(struct Curl_cfilter *cf,
                                        GSS_C_NT_HOSTBASED_SERVICE, &server);
   }
 
-  gss_release_buffer(&gss_status, &service); /* clear allocated memory */
+  Curl_safefree(service.value);
 
   if(check_gss_err(data, gss_major_status,
                    gss_minor_status, "gss_import_name()")) {
@@ -192,7 +192,7 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(struct Curl_cfilter *cf,
                                                  &gss_ret_flags);
 
     if(gss_token != GSS_C_NO_BUFFER)
-      gss_release_buffer(&gss_status, &gss_recv_token);
+      Curl_safefree(gss_recv_token.value);
     if(check_gss_err(data, gss_major_status,
                      gss_minor_status, "gss_init_sec_context") ||
        /* the size needs to fit in a 16 bit field */
@@ -276,7 +276,7 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(struct Curl_cfilter *cf,
     us_length = ntohs(us_length);
 
     gss_recv_token.length = us_length;
-    gss_recv_token.value = malloc(us_length);
+    gss_recv_token.value = malloc(gss_recv_token.length);
     if(!gss_recv_token.value) {
       failf(data,
             "Could not allocate memory for GSS-API authentication "
@@ -292,7 +292,7 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(struct Curl_cfilter *cf,
     if(result || (actualread != us_length)) {
       failf(data, "Failed to receive GSS-API authentication token.");
       gss_release_name(&gss_status, &server);
-      gss_release_buffer(&gss_status, &gss_recv_token);
+      Curl_safefree(gss_recv_token.value);
       Curl_gss_delete_sec_context(&gss_status, &gss_context, NULL);
       return CURLE_COULDNT_CONNECT;
     }
@@ -391,7 +391,7 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(struct Curl_cfilter *cf,
   }
   else {
     gss_send_token.length = 1;
-    gss_send_token.value = Curl_memdup(&gss_enc, 1);
+    gss_send_token.value = Curl_memdup(&gss_enc, gss_send_token.length);
     if(!gss_send_token.value) {
       Curl_gss_delete_sec_context(&gss_status, &gss_context, NULL);
       return CURLE_OUT_OF_MEMORY;
@@ -402,13 +402,13 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(struct Curl_cfilter *cf,
                                 &gss_conf_state, &gss_w_token);
 
     if(check_gss_err(data, gss_major_status, gss_minor_status, "gss_wrap")) {
-      gss_release_buffer(&gss_status, &gss_send_token);
+      Curl_safefree(gss_send_token.value);
       gss_release_buffer(&gss_status, &gss_w_token);
       Curl_gss_delete_sec_context(&gss_status, &gss_context, NULL);
       failf(data, "Failed to wrap GSS-API encryption value into token.");
       return CURLE_COULDNT_CONNECT;
     }
-    gss_release_buffer(&gss_status, &gss_send_token);
+    Curl_safefree(gss_send_token.value);
 
     us_length = htons((unsigned short)gss_w_token.length);
     memcpy(socksreq + 2, &us_length, sizeof(short));
@@ -481,7 +481,7 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(struct Curl_cfilter *cf,
 
   if(result || (actualread != us_length)) {
     failf(data, "Failed to receive GSS-API encryption type.");
-    gss_release_buffer(&gss_status, &gss_recv_token);
+    Curl_safefree(gss_recv_token.value);
     Curl_gss_delete_sec_context(&gss_status, &gss_context, NULL);
     return CURLE_COULDNT_CONNECT;
   }
@@ -492,13 +492,13 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(struct Curl_cfilter *cf,
                                   0, GSS_C_QOP_DEFAULT);
 
     if(check_gss_err(data, gss_major_status, gss_minor_status, "gss_unwrap")) {
-      gss_release_buffer(&gss_status, &gss_recv_token);
+      Curl_safefree(gss_recv_token.value);
       gss_release_buffer(&gss_status, &gss_w_token);
       Curl_gss_delete_sec_context(&gss_status, &gss_context, NULL);
       failf(data, "Failed to unwrap GSS-API encryption value into token.");
       return CURLE_COULDNT_CONNECT;
     }
-    gss_release_buffer(&gss_status, &gss_recv_token);
+    Curl_safefree(gss_recv_token.value);
 
     if(gss_w_token.length != 1) {
       failf(data, "Invalid GSS-API encryption response length (%zu).",
@@ -515,13 +515,13 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(struct Curl_cfilter *cf,
     if(gss_recv_token.length != 1) {
       failf(data, "Invalid GSS-API encryption response length (%zu).",
             gss_recv_token.length);
-      gss_release_buffer(&gss_status, &gss_recv_token);
+      Curl_safefree(gss_recv_token.value);
       Curl_gss_delete_sec_context(&gss_status, &gss_context, NULL);
       return CURLE_COULDNT_CONNECT;
     }
 
     memcpy(socksreq, gss_recv_token.value, gss_recv_token.length);
-    gss_release_buffer(&gss_status, &gss_recv_token);
+    Curl_safefree(gss_recv_token.value);
   }
 
   (void)curlx_nonblock(sock, TRUE);