From 2d419e90f92890f55d5179ff8578d274cbfcc1f4 Mon Sep 17 00:00:00 2001
From: Thomas Faber <thomas.faber@reactos.org>
Date: Sat, 20 Apr 2019 10:49:13 +0200
Subject: [PATCH] [NTOS:PNP] Reduce the default buffer size in
 EnumerateDevices. CORE-15882

---
 ntoskrnl/io/pnpmgr/pnproot.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/ntoskrnl/io/pnpmgr/pnproot.c b/ntoskrnl/io/pnpmgr/pnproot.c
index 65ea5cc937b..03ae98131d6 100644
--- a/ntoskrnl/io/pnpmgr/pnproot.c
+++ b/ntoskrnl/io/pnpmgr/pnproot.c
@@ -461,7 +461,8 @@ EnumerateDevices(
     DeviceExtension = (PPNPROOT_FDO_DEVICE_EXTENSION)DeviceObject->DeviceExtension;
     KeAcquireGuardedMutex(&DeviceExtension->DeviceListLock);
 
-    KeyInfoSize = sizeof(KEY_BASIC_INFORMATION) + (MAX_PATH + 1) * sizeof(WCHAR);
+    /* Should hold most key names, but we reallocate below if it's too small */
+    KeyInfoSize = FIELD_OFFSET(KEY_BASIC_INFORMATION, Name) + 64 * sizeof(WCHAR);
     KeyInfo = ExAllocatePoolWithTag(PagedPool,
                                     KeyInfoSize + sizeof(UNICODE_NULL),
                                     TAG_PNP_ROOT);