From aca31249ed43050ced1c939ed9d9631e8607819e Mon Sep 17 00:00:00 2001
From: Owen Smith <owen.smith@cloud.com>
Date: Mon, 17 Apr 2023 14:24:39 +0100
Subject: [PATCH] Check for zero byte allocations

Avoid attempting to allocate zero byte buffers, which can lead to
inefficiencies in pool memory usage.

Suggested-by: Matthew Sykes <matthew.sykes@citrix.com>
Signed-off-by: Owen Smith <owen.smith@cloud.com>
---
 src/xenvkbd/util.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/xenvkbd/util.h b/src/xenvkbd/util.h
index f393709..495162e 100644
--- a/src/xenvkbd/util.h
+++ b/src/xenvkbd/util.h
@@ -153,6 +153,9 @@ __AllocatePoolWithTag(
     __analysis_assume(PoolType == NonPagedPool ||
                       PoolType == PagedPool);
 
+    if (NumberOfBytes == 0)
+        return NULL;
+
 #if (_MSC_VER >= 1928) // VS 16.9 (EWDK 20344 or later)
     Buffer = ExAllocatePoolUninitialized(PoolType, NumberOfBytes, Tag);
 #else
-- 
2.39.5