From 842605e3ef6c3673d8846181787c1f671a2e8c24 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Herm=C3=A8s=20B=C3=A9lusca-Ma=C3=AFto?=
 <hermes.belusca-maito@reactos.org>
Date: Sun, 1 Apr 2018 15:53:49 +0200
Subject: [PATCH] [NTOSKRNL] Don't emit hard errors for the calling thread if
 hard errors have been disabled for this thread on user-mode side.

---
 ntoskrnl/ex/harderr.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/ntoskrnl/ex/harderr.c b/ntoskrnl/ex/harderr.c
index 82d22f49263..185d43537ee 100644
--- a/ntoskrnl/ex/harderr.c
+++ b/ntoskrnl/ex/harderr.c
@@ -105,13 +105,14 @@ ExpRaiseHardError(IN NTSTATUS ErrorStatus,
                   IN ULONG ValidResponseOptions,
                   OUT PULONG Response)
 {
+    NTSTATUS Status;
     PEPROCESS Process = PsGetCurrentProcess();
     PETHREAD Thread = PsGetCurrentThread();
     UCHAR Buffer[PORT_MAXIMUM_MESSAGE_LENGTH];
     PHARDERROR_MSG Message = (PHARDERROR_MSG)Buffer;
-    NTSTATUS Status;
     HANDLE PortHandle;
     KPROCESSOR_MODE PreviousMode = KeGetPreviousMode();
+
     PAGED_CODE();
 
     /* Check if this error will shutdown the system */
@@ -182,6 +183,31 @@ ExpRaiseHardError(IN NTSTATUS ErrorStatus,
     /* If hard errors are disabled, do nothing */
     if (Thread->HardErrorsAreDisabled) PortHandle = NULL;
 
+    /*
+     * If this is not the system thread, check whether hard errors are
+     * disabled for this thread on user-mode side, and if so, do nothing.
+     */
+    if (!Thread->SystemThread && (PortHandle != NULL))
+    {
+        /* Check if we have a TEB */
+        PTEB Teb = PsGetCurrentThread()->Tcb.Teb;
+        if (Teb)
+        {
+            _SEH2_TRY
+            {
+                if (Teb->HardErrorMode & RTL_SEM_FAILCRITICALERRORS)
+                {
+                    PortHandle = NULL;
+                }
+            }
+            _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
+            {
+                NOTHING;
+            }
+            _SEH2_END;
+        }
+    }
+
     /* Now check if we have a port */
     if (PortHandle == NULL)
     {