- Stay attached while deleting the VAD node
- Acquire the appropriate working set lock when deleting a VAD node
- Both are needed for locking correctness
- Acquire the appropriate working set lock when calling MmLocateMemoryAreaByAddress
- Do not access MemoryArea without holding the lock (otherwise it can be pulled away under our feet)
- Fix range check for paged pool
These faults are handled by ARM³ and we don't need to check for a memory area. They can be recursive faults (e.g. from MiDeleteSystemPageableVm), so we might be holding the WS lock already. Passing it straight to ARM³ allows to acquire the WS lock below to look up the memory area.
Addendum to commit b3c55b9e6 (PR #4399).
Passing &CapturedObjectName as pointer to be probed and captured would
fail if e.g. PreviousMode == UserMode, since that pointer is always in
kernel space. Instead, pass the original user-mode pointer.
Bug caught by Timo Kreuzer ;)
This is a hack, because the kernel mode path can incur a recursive page fault with the AddressCreationLock acquired, which would lead to a recursive acquisition, once we do proper locking in MmAccessFault.
To properly fix this the PDE must be made valid, similar to the user mode path, but that is not that simple...
They can be spammy. Also clarify these debug prints, because some people
think that "failed to grant access rights" means there's something wrong
in the core access check functions.
Temporarily add the local group to the system token so that Virtualbox
GA services can properly set up network drives for shared folders.
What happens is that a security descriptor has a DACL with only one ACE
that grants access to Local SID (presumably coming from Vbox?)
but the client token is that of the service which is a SYSTEM token.
Perhaps we are not impersonating the right user or whatever else.
This is only a temporary placebo, until a proper solution is found.
CORE-18250
Certain apps such as AIM installer passes an empty generic mapping (this can
be understood with their generic masks set to 0) and our code tries to map
the access right from an ACE with the mapping provided by AccessCheck.
This can lead to a bug where we would not be able to decode the generic right
from an ACE as we need a proper generic mapping in order to do so. A mask
right that is not decoded it cannot be used to mask out the remaining rights,
further resulting into a denied access right.
What Windows does instead is they are mapping the ACE's rights in another place,
presumably when setting security data to an object, and they are using the
generic mapping passed by the kernel.
What we can do for the time being is to temporarily grant access to the client,
but only if they are an administrator.
CORE-18576
During an open or create procedure of a registry key, the registry parser grabs
a key control block (KCB) from the parser object and uses its information to do the
necessary work in order to obtain a pointer to the newly created or opened registry key.
However, the registry parsers faces several issues. First, we don't do subkey cache cleaning
information against gathered KCBs so whenever we do a registry parse we end up with KCBs
that have cache inconsistencies. Moreover we don't do any locking of whatever KCB we
are grabing during a parse procedure.
=== PROPOSED CHANGES ===
* Implement CmpComputeHashValue and CmpLookInCache functions. With CmpComputeHashValue we can
compute the convkey hashes of each subkey in the path name of a key so we can lock them
with CmpBuildAndLockKcbArray. CmpLookInCache is a function that searches for the suitable
KCB in the cache. The factors that determine if a KCB is "suitable" are:
-- the currently found KCB in the hash list has the same levels as that of the
given KCB from the parse object;
-- The key names from the computed hash values match with the block name of
the KCB;
-- The currently found KCB is not deleted.
The KCB will be changed if the key path name points to a partial match name in
the cache. The KCB from the parse object will be used if we have a full match
of remaining levels.
* Add missing CMP_LOCK_HASHES_FOR_KCB flags on CmpCreateKeyControlBlock calls
that create KCBs during a parse procedure. Such lock has to be preserved until
we're done with the registry parsing.
* On CmpDoCreateChild, preserve the exclusive lock of the KCB when we are
enlisting the key body.
* On CmpDoCreate, make sure that the passed parent KCB is locked exclusively and
lock the hiver flusher as we don't want the flusher to kick in during a key
creation on the given hive. Cleanup the subkey info when we're creating a key
object. Also implement missing cleanup path codes. Furthermore, avoid key
object creation if the parent KCB is protected with a read-only switch.
* Soft rewrite the CmpDoOpen function, namely how we manage a direct open vs
create KCB on open scenario. When a KCB is found in cache avoid touching
the key node. If the symbolic link has been resolved (aka found) then lock
exclusively the symbolic KCB. Otherwise just give the cached KCB to the caller.
If it were for the caller to request a KCB creation, we must check the passed
KCB from the parser object is locked exclusively, unlike on the case above
the caller doesn't want to create a KCB because there's already one in the cache.
We don't want anybody to touch our KCB while we are still toying with it during
its birth. Furthermore, enlist the key body but mind the kind of lock it's been
used.
* On CmpCreateLinkNode, avoid creating a key object if the parent KCB is protected
with a read-only switch. In addition, add missing hive flusher locks for both
the target hive and its child. Cleanup the subkey information of the KCB when
creating a link node, this ensures our cached KCB data remains consistent.
* Do a direct open on CmpParseKey if no remaining subkey levels have been found
during hash computation and cache lookup, in this case the given KCB is the
block that points to the exact key. This happens when for example someone tried
to call RegOpenKeyExW but submitting NULL to the lpSubKey argument parameter.
CORE-10581
ROSTESTS-198
CmpSecurityMethod is a method used by the Object Manager and called by this
subsystem whenever a security operation has to be done against a key object.
As CmpSecurityMethod is a specific OB construct we should not make any direct
call attempts to CmpSecurityMethod, only OB is responsible for that. This fixes
a deadlock where CmpSecurityMethod acquires a push lock for exclusive access
even though such lock is already acquired by the same calling thread in
CmpDoCreateChild.
This prevents a deadlock in DelistKeyBodyFromKCB when we delete a key
object because of an access check failure during a open procedure of a
registry key, as we are already holding a lock against the target KCB of
the key body.
Whenever a security request is invoked into a key object, such as when requesting
information from its security descriptor, the Object Manager will execute
the CmpSecurityMethod method to do the job.
The problem is that CmpSecurityMethod is not aware if the key control block
of the key body already has a lock acquired which means the function will attempt
to acquire a lock again, leading to a deadlock. This happens if the same
calling thread locks the KCB but it also wants to acquire security information
with ObCheckObjectAccess in CmpDoOpen.
Windows has a hack in CmpSecurityMethod where the passed KCB pointer is ORed
with a bitfield mask to avoid locking in all cases. This is ugly because it negates
every thread to acquire a lock if at least one has it.
The CmpUnLockKcbArray, CmpLockKcbArray and CmpBuildAndLockKcbArray routines
help us to lock KCBs within array so that information remains consistent when
we are doing a cache lookup during a parse procedure of the registry database.
Implement CmpBuildAndLockKcbArray and CmpUnLockKcbArray prototypes, we'll gonna need these
to do the locking/unlocking of KCBs stacked up in an array. In addition implement some CM
constructs specifically for cache lookup implementation (more at documentation remarks).
=== DOCUMENTATION REMARKS ===
CMP_SUBKEY_LEVELS_DEPTH_LIMIT -- This is the limit of up to 32 subkey levels
that the registry can permit. This is used in CmpComputeHashValue to ensure
that we don't compute more than the limit of subkeys we're allowed to.
CMP_KCBS_IN_ARRAY_LIMIT -- This is equal to CMP_SUBKEY_LEVELS_DEPTH_LIMIT
plus the addition by 2. This construct is used as a limit of KCB elements
the array can hold. 2 serves as an additional space for the array (one for
the root object and another one as extra space so we don't blow up the stack
array).
CMP_LOCK_KCB_ARRAY_EXCLUSIVE & CMP_LOCK_KCB_ARRAY_SHARED -- These flags are used exclusively
for CmpBuildAndLockKcbArray and CmpLockKcbArray. Their meaning are obvious.
CM_HASH_CACHE_STACK -- A structure used to store the hashes of KCBs for locking. It is named
"stack" because the way we store the hashes of KCBs is within an auxilliary "outer stack array".
CmpAcquireKcbLockSharedByKey can come in handy for use to lock KCBs by their convkey with a shared lock, specifically we would need this for cache lookup stuff.
- RtlpQuerySecurityDescriptor: Change argument type of first parameter from PISECURITY_DESCRIPTOR to PSECURITY_DESCRIPTOR, since it handles both absolute and self-relative SDs.
- RtlMakeSelfRelativeSD: rename first parameter from AbsoluteSD to SecurityDescriptor, since it handles both absolute and self-relative SDs.
- SepGetGroupFromDescriptor/SepGetOwnerFromDescriptor/SepGetDaclFromDescriptor/SepGetSaclFromDescriptor: Change parameter type from PVOID to PSECURITY_DESCRIPTOR for clarity.
The code was passing 0 instead of SECTION_INHERIT::ViewUnmap (2). 0 isn't even a proper constant to be used here. It worked, because MmMapViewOfSection only compares against ViewShare (1) and treats everything else as ViewUnmap.
The function set CtxSwitchFrame->ApcBypass to FALSE, preventing APCs (like when user mode sets the context while the thread is suspended) from being delivered as soon as the thread lowers IRQL to PASSIVE_LEVEL. This resulted in the SetContext APC to be delivered only after the user mode APC was initialized, overwriting the user mode APC context in the trap frame. This caused kernel32_winetest process to break.
Now that the Memory Management is a bit more under control again,
and branching releases/0.4.15 is near,
do mute some frequent log-spam that got introduced during 0.4.15-dev'ing
regarding lazy-flushes and MM balancing.
It frequently logged even while being idle.
Slightly improve the headers of the two touched files.
No rocket-science.
- They notify, via the "\\Callback\\SetSystemTime" callback, components
of a change of system time (for example, Win32k).
Note, that our Win32k currently does not handle power callouts, so
it isn't affected by these changes (yet).
- NtSetSystemTime(NULL, ...) means "update system time using the current
time-zone information", which is something we don't implement yet.
(And, nothing was previously protecting this call from a NULL parameter...)
Add redirections for KdSave/KdRestore and KdD0Transition/KdD3Transition.
Both KDBG and KD(TERM) need those since they will become external
transport DLLs later.
Split KdSendPacket and KdReceivePacket into those that manipulate the
KDBG state proper (reside in kdbg/kdbg.c), and those that deal only with
debug input/output that will reside in a KDTERM "KD Terminal Driver" DLL.
Based on some previous preparatory work by Hervé Poussineau in PR #4600.
(Equivalents of commits 5162bf106 and partly e9bcf7275.)
As it turns out, those three functions were duplicating the same code
between each other. Reimplement these in terms of a common helper,
RtlFindExportedRoutineByName().
Indeed: MiFindExportedRoutineByName() was just MiLocateExportName()
but taking a PANSI_STRING instead of a NULL-terminated string.
A similar state of affairs also existed in Windows <= 2003, and the
MS guys also noticed it. Both routines have been then merged and renamed
to MiFindExportedRoutineByName() on Windows 8 (taking a PCSTR instead),
and finally renamed and exported as RtlFindExportedRoutineByName()
on Windows 10.
