[reactos] 01/01: [NTOS:MM] Do proper checks & acquire proper locks when sweeping user pages

[Jérôme Gardou]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=7c006df7e0ea1fe321513…

commit 7c006df7e0ea1fe3215137199bca7f4a0215a351
Author:     Jérôme Gardou <jerome.gardou(a)reactos.org>
AuthorDate: Wed Aug 4 20:35:14 2021 +0200
Commit:     Jérôme Gardou <jerome.gardou(a)reactos.org>
CommitDate: Wed Aug 4 20:38:37 2021 +0200

    [NTOS:MM] Do proper checks & acquire proper locks when sweeping user pages
    
    CORE-17595
---
 ntoskrnl/mm/balance.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/ntoskrnl/mm/balance.c b/ntoskrnl/mm/balance.c
index 0eec51fbb88..fe882aff6c4 100644
--- a/ntoskrnl/mm/balance.c
+++ b/ntoskrnl/mm/balance.c
@@ -213,15 +213,22 @@ MmTrimUserMemory(ULONG Target, ULONG Priority, PULONG NrFreedPages)
 
                 MmLockAddressSpace(&Process->Vm);
 
-                /* Be sure this is still valid. */
-                PMMPTE Pte = MiAddressToPte(Address);
-                if (Pte->u.Hard.Valid)
+                if (!Process->VmDeleted)
                 {
-                    Accessed = Accessed || Pte->u.Hard.Accessed;
-                    Pte->u.Hard.Accessed = 0;
+                    MiLockProcessWorkingSetUnsafe(Process, PsGetCurrentThread());
 
-                    /* There is no need to invalidate, the balancer thread is never on a
user process */
-                    //KeInvalidateTlbEntry(Address);
+                    /* Be sure this is still valid. */
+                    if (MmIsAddressValid(Address))
+                    {
+                        PMMPTE Pte = MiAddressToPte(Address);
+                        Accessed = Accessed || Pte->u.Hard.Accessed;
+                        Pte->u.Hard.Accessed = 0;
+
+                        /* There is no need to invalidate, the balancer thread is never
on a user process */
+                        //KeInvalidateTlbEntry(Address);
+                    }
+
+                    MiUnlockProcessWorkingSet(Process, PsGetCurrentThread());
                 }
 
                 MmUnlockAddressSpace(&Process->Vm);