Fix potential TunDispatchSecurityDescriptor leak

TunDispatchSecurityDescriptor will leak if RtlAbsoluteToSelfRelativeSD
fails. Add cleanup in error path.

Reported-by: Shawn Hoffman <godisgovernment@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/wintun.c b/wintun.c
index 12ef467..9e10e13 100644
--- a/wintun.c
+++ b/wintun.c
@@ -816,7 +816,10 @@ static NTSTATUS TunInitializeDispatchSecurityDescriptor(VOID)
         return STATUS_INSUFFICIENT_RESOURCES;
     Status = RtlAbsoluteToSelfRelativeSD(&SecurityDescriptor, TunDispatchSecurityDescriptor, &RequiredBytes);
     if (!NT_SUCCESS(Status))
+    {
+        ExFreePoolWithTag(TunDispatchSecurityDescriptor, TUN_MEMORY_TAG);
         return Status;
+    }
     return STATUS_SUCCESS;
 }