This reverts 8479509 commit which pretty much does nothing at all (the captured pointer is NULL within the stack of the function has no effect outside of the function). My mistake, sorry.
Whenever a captured security property such as privilege or SID is released, we must not have such captured property point at random address in memory but rather we must assign it as NULL after it's been freed from pool memory. This avoids potential double-after-free situations where we might release a buffer twice.
This is exactly the case with token filtering.
Before purging the data cache of a certain section of a file from system cache, we have to unintialize the private cache maps of that section if a filesystem or any other component prompts the kernel to do so.
Currently, these features are vital for the kernel:
- CPUID instruction
- CMPXCHG8B instruction
- TSC aka Time Stamp Counter
All of that have to be present on i586
As it currently stands the Object Manager doesn't charge any quotas when objects are created, nor it returns quotas when objects are de-allocated and freed from the objects namespace database. This alone can bring inconsistencies in the kernel as we simply don't know what is the amount charged in an object and thus we aren't keeping track of quotas flow.
Now with both PsReturnSharedPoolQuota and PsChargeSharedPoolQuota implemented, the Object Manager can now track the said flow of quotas every time an object is created or de-allocated, thus enforcing consistency with the use of quota resources.
Ensure that when we're cleaning up the EPROCESS object, that we are dereferencing the quota block the process in question was using. The routine will automatically request a quota block cleanup if the process that dereferenced the quota block was the last.
-- Rewrite PspChargeProcessQuotaSpecifiedPool and PspReturnProcessQuotaSpecifiedPool private kernel routines, with the goal to implement the algorithms necessary to manage the fields of quota blocks (Usage, Return, Limit and Peak).
-- Invoke the Mm if quota limit raising or returning has to be done
-- When destroying a quota block, make sure that we're giving back all the rest of non-returned quotas to Memory Mm
-- Crash the system with QUOTA_UNDERFLOW if someone is returning way too much quota than it was previously charged
-- When a process exits, ensure that it doesn't hold up any charged quotas in QuotaUsage field of the process object, that way we're enforcing proper kernel consistency
-- Implement PsChargeSharedPoolQuota and PsChargeProcessPageFileQuota functions, used exclusively by the Object Manager. These routines are used to charge or return amount of quotas of a newly created object.
-- On PspInheritQuota, when assigning to process the default quota block if no parent process is given, we must increment the reference counts as we're using it
-- Handle the ProcessCount reference field, as it wasn't used
-- Annotate the functions with SAL
-- Document the code
=== REMARKS ===
Windows LogOn (Winlogon) is responsible for setting up a different quota block for all the processes within an interactive session, which is what we don't do. What we're currently doing instead is we're using the default block, PspDefaultQuotaBlock, for all the processes
across the system. The default block contains the default limits of -1 (which would imply no limits). By definition, the kernel won't ever return STATUS_QUOTA_EXCEEDED as we literally don't set up a definite limit for regular processes. This situation has to be tackled
in the future.
=== TODO FOR FUTURE ===
Most of the code in PspChargeProcessQuotaSpecifiedPool and PspReturnProcessQuotaSpecifiedPool private routines must be refactored in order to reduce the usage of the quota spin lock, possibly wrapping such code in a loop and whatnot.
CORE-17784
This implements both MmRaisePoolQuota and MmReturnPoolQuota functions, which serve exclusively for quota pool management. The process manager communicates with the memory manager in a call of need to charge or return pool quota limits.
OBP_SYSTEM_PROCESS_QUOTA is a macro that'll be used as a way to assign a dummy quota block to system processes, as we mustn't do anything to those in case the Object Manager is charging or returning pool quotas.
Declare PsReturnSharedPoolQuota and PsChargeSharedPoolQuota prototypes and annotate the functions. Furthermore, add two definitions related to quota pool limits threshold -- PSP_NON_PAGED_POOL_QUOTA_THRESHOLD and PSP_PAGED_POOL_QUOTA_THRESHOLD. For further details, see the commit description of "[NTOS:MM] Add the pool quota prototypes and some definitions".
Declare the MmRaisePoolQuota and MmReturnPoolQuota prototypes in the header and add some definitions related to pool quotas, namely MmTotalNonPagedPoolQuota and MmTotalPagedPoolQuota. These variables are used internally by the kernel as sort of "containers" (for the lack of a better term)
which uphold the amount of quotas that the Process Manager is requesting the Memory Manager to raise or return the pool quota limit. In addition to that, add some definitions needed for both of these functions.
The definitions, MI_CHARGE_PAGED_POOL_QUOTA and MI_CHARGE_NON_PAGED_POOL_QUOTA respectively, bear some interesting aspect. Seemingly the 0x80000 and 0x10000 values (that would denote to 524288 and 65536 specifically) are used as quota "limits" or in other words, thresholds that the kernel
uses. So for example if one would want to raise the quota limit charge, MmRaisePoolQuota will raise it so based on this formula -- NewMaxQuota = CurrentQuota + LIMIT_VALUE. LIMIT_VALUE can be either MI_CHARGE_PAGED_POOL_QUOTA or MI_CHARGE_NON_PAGED_POOL_QUOTA, depending a per quota pool basis.
What's more interesting is that these values are pervasive in Process Manager even. This is when quotas are to be returned back and trim the limit of the quota block if needed, the kernel would either take the amount provided by the caller of quotas to return or the threshold (paged or not paged)
if the amount to return exceeds the said threshold in question.
This fixes an issue where ReactOS would assert on QuotaUsage == 0 as the process was still taking up quotas during a quota block de-reference with root cause of ThisBufferLength member field being 0 which made process quota charging/returning flow unbalanced.
In addition to that, on FsRtlCancelNotify routine API all we must ensure that if PsChargePoolQuota or ExAllocatePoolWithTag function fails we have to handle the raised exceptions accordingly and return the charged quota back (if we actually charged quotas that is). With said, wrap that part of code with SEH.
=== DOCUMENTATION REMARKS ===
The cause of the assert is due to the fact ThisBufferLength was being handled wrongly ever since, until this commit. When FsRtl of the Executive has to filter reported changes (with logic algorithm implemented in FsRtlNotifyFilterReportChange function), the said function will charge the quota of a given process
with an amount that is represented as the buffer length whose size is expressed in bytes. This length buffer is preserved in a local variable called NumberOfBytes, which is initialized from BufferLength member field of notification structure or from the length from stack parameters pointed from an IRP.
As it currently stands, the code is implemented in such a way that FsRtlNotifyFilterReportChange will charge quotas to a process but it doesn't assign the buffer length to ThisBufferLength. On the first glimpse ThisBufferLength and BufferLength are very similar members that serve exact same purpose but in reality there's a subtle distinction between the two.
BufferLength is a member whose length size is given by FSDs (filesystem drivers) during a notification dispatching. Whenever FsRtl receives the notification structure packed with data from the filesystem, the length pointed by BufferLength gets passed to ThisBufferLength and from now on the kernel has to use this member for the whole time of its task to accomplish
whatever request it's been given by the filesystem. In other words, BufferLength is strictly used only to pass length size data to the kernel by initializing ThisBufferLength based on that length and unequivocally the kernel uses this member field. What we're doing is that ThisBufferLength never receives the length from BufferLength therefore whenever FsRtl component
has to return quotas back it'll return an amount of 0 (which means no amount to return) and that's a bug in the kernel.
Also generate processor identifier properly based on this value
on the Configuration Manager machine-dependent initialization.
Update processor driver INF file accordingly.
CORE-17970 CORE-14922
We have a special file, tag.h, which serves as a place to store whatever kernel pool allocation tag yet we still have some tags sparse over the kernel code... So just re-group them in one unique place.
SIDs are variadic by nature which means their lengths can vary in a given amount of time and certain factors that allow for this happen. This also especially can lead to issues when capturing SIDs and attributes because SeCaptureSidAndAttributesArray might end up overwriting the buffer during the time it's been called.
Therefore when we're copying the SIDs, validate their lengths. In addition to that, update the documentation header accordingly and add some debug prints in code.
NormalContext and NormalRoutine are just for good measure, but
SystemArgument2 is actually used by the function.
And yes, this appears to be a bug in Win 2003.
This implements the support of token filtering within the kernel, where the kernel can create restricted tokens of regular ones on demand by the caller. The implementation can be accessed thorough a NT syscall, NtFilterToken, and a kernel mode routine, SeFilterToken.
The continue statements do not server any useful purpose in these loops so they're basically pointless. These have been introduced by mistake so my bad.
