[tfaber] 72873: [NTOS:EX] - Acquire ProcessLock before accessing a process's thread list in NtQuerySystemInformation/SystemProcessInformation. Patch by Volodymyr Shcherbyna. CORE-12001 #resolve

Author: tfaber
Date: Sat Oct  1 09:03:47 2016
New Revision: 72873

URL: http://svn.reactos.org/svn/reactos?rev=72873&view=rev
Log:
[NTOS:EX]
- Acquire ProcessLock before accessing a process's thread list in
NtQuerySystemInformation/SystemProcessInformation. Patch by Volodymyr Shcherbyna.
CORE-12001 #resolve

Modified:
    trunk/reactos/ntoskrnl/ex/sysinfo.c

Modified: trunk/reactos/ntoskrnl/ex/sysinfo.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ex/sysinfo.c?rev=…
==============================================================================
--- trunk/reactos/ntoskrnl/ex/sysinfo.c	[iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/ex/sysinfo.c	[iso-8859-1] Sat Oct  1 09:03:47 2016
@@ -812,6 +812,10 @@
         {
             SpiCurrent = (PSYSTEM_PROCESS_INFORMATION) Current;
 
+            /* Lock the Process */
+            KeEnterCriticalRegion();
+            ExAcquirePushLockShared(&Process->ProcessLock);
+
             if ((Process->ProcessExiting) &&
                 (Process->Pcb.Header.SignalState) &&
                 !(Process->ActiveThreads) &&
@@ -821,6 +825,10 @@
                         Process, Process->ImageFileName,
Process->UniqueProcessId);
                 CurrentSize = 0;
                 ImageNameMaximumLength = 0;
+
+                /* Unlock the Process */
+                ExReleasePushLockShared(&Process->ProcessLock);
+                KeLeaveCriticalRegion();
                 goto Skip;
             }
 
@@ -954,6 +962,10 @@
                 ExFreePoolWithTag(ProcessImageName, TAG_SEPA);
                 ProcessImageName = NULL;
             }
+
+            /* Unlock the Process */
+            ExReleasePushLockShared(&Process->ProcessLock);
+            KeLeaveCriticalRegion();
 
             /* Handle idle process entry */
 Skip: