[reactos] 01/01: [NTOS:FSRTL] Check for the correct return status when inserting a new Filter Context entry According to our declaration/definition, IoChangeFileObjectFilerContext returns NTSTATUS, not BOOLEAN. Zero return (which was actually checked before) for BOOLEAN means failure, but for NTSTATUS it's success. So it should (and now actually does) free and fail appropriately only in failure case, but not in success, when it shouldn't. This fixes most of problems with fltmgr.sys driver from W

[Oleg Dubinskiy]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=c59e2d20d9c8a42f3c944…

commit c59e2d20d9c8a42f3c94403282efcab1cbe20fd9
Author:     Oleg Dubinskiy <oleg.dubinskij30(a)gmail.com>
AuthorDate: Mon Aug 26 11:16:49 2024 +0200
Commit:     Oleg Dubinskiy <oleg.dubinskij30(a)gmail.com>
CommitDate: Mon Aug 26 11:16:49 2024 +0200

    [NTOS:FSRTL] Check for the correct return status when inserting a new Filter Context
entry
    According to our declaration/definition, IoChangeFileObjectFilerContext returns
NTSTATUS, not BOOLEAN. Zero return (which was actually checked before) for BOOLEAN means
failure, but for NTSTATUS it's success. So it should (and now actually does) free and
fail appropriately only in failure case, but not in success, when it shouldn't.
    This fixes most of problems with fltmgr.sys driver from Windows XP/Server 2003 and a
lot of 3rd party filter drivers which use it from many apps (Avast Free Antivirus all
versions, Avira AntiVir Personal 8.2, Dr. Web Security Space 8.0, Kaspersky Antivirus 2012
etc. etc.).
    CORE-14157, CORE-14635, CORE-19318
---
 ntoskrnl/fsrtl/filtrctx.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/ntoskrnl/fsrtl/filtrctx.c b/ntoskrnl/fsrtl/filtrctx.c
index 9bd616fad7a..a71475a93bc 100644
--- a/ntoskrnl/fsrtl/filtrctx.c
+++ b/ntoskrnl/fsrtl/filtrctx.c
@@ -176,6 +176,7 @@ FsRtlInsertPerFileObjectContext(IN PFILE_OBJECT FileObject,
                                 IN PFSRTL_PER_FILEOBJECT_CONTEXT Ptr)
 {
     PFILE_OBJECT_FILTER_CONTEXTS FOContext = NULL;
+    NTSTATUS Status;
 
     if (!FileObject)
     {
@@ -203,7 +204,8 @@ FsRtlInsertPerFileObjectContext(IN PFILE_OBJECT FileObject,
         InitializeListHead(&(FOContext->FilterContexts));
 
         /* Set it */
-        if (!IoChangeFileObjectFilterContext(FileObject, FOContext, TRUE))
+        Status = IoChangeFileObjectFilterContext(FileObject, FOContext, TRUE);
+        if (!NT_SUCCESS(Status))
         {
             /* If it fails, it means that someone else has set it in the meanwhile */
             ExFreePoolWithTag(FOContext, 'FOCX');