CVE-2022-3437 source4/heimdal: Don't pass NULL pointers to memcpy() in DES unwrap

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15134

Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/source4/heimdal/lib/gssapi/krb5/unwrap.c b/source4/heimdal/lib/gssapi/krb5/unwrap.c
index 7111a7944fe0d55c94fe9a1c06166722b0fe94f8..9639091cb3a63b51829f372ff1a2ea8f3b310843 100644 (file)
--- a/source4/heimdal/lib/gssapi/krb5/unwrap.c
+++ b/source4/heimdal/lib/gssapi/krb5/unwrap.c
@@ -180,9 +180,10 @@ unwrap_des
   output_message_buffer->value  = malloc(output_message_buffer->length);
   if(output_message_buffer->length != 0 && output_message_buffer->value == NULL)
       return GSS_S_FAILURE;
-  memcpy (output_message_buffer->value,
-         p + 24,
-         output_message_buffer->length);
+  if (output_message_buffer->value != NULL)
+      memcpy (output_message_buffer->value,
+             p + 24,
+             output_message_buffer->length);
   return GSS_S_COMPLETE;
 }
 #endif
@@ -374,9 +375,10 @@ unwrap_des3
   output_message_buffer->value  = malloc(output_message_buffer->length);
   if(output_message_buffer->length != 0 && output_message_buffer->value == NULL)
       return GSS_S_FAILURE;
-  memcpy (output_message_buffer->value,
-         p + 36,
-         output_message_buffer->length);
+  if (output_message_buffer->value != NULL)
+      memcpy (output_message_buffer->value,
+             p + 36,
+             output_message_buffer->length);
   return GSS_S_COMPLETE;
 }