Revert "[NTOS] On DBG builds, fill pool allocations with 0xCD and freed pool with 0xDD"
This reverts commit 24f240be8a.
Revert "[NTOS] Add compile time option to trace callers of pool allocations"
This reverts commit 8b20755040.
Revert "WIP"
This reverts commit 8cfd5c601f.
As documented in https://docs.microsoft.com/fr-fr/windows-hardware/drivers/ddi/wdm/nf-wdm-exallocatepoolwithtag
pool tag "characters" must be a value in the range 0x20 (space) to 0x7E (tilde),
which happen indeed to be the range of printable (non-extended) ASCII characters.
(The display problem was originally caught while attempting to display
the pool tag 0x3a306847 corresponding to 'Gh0:', a win32ss GDIOBJ pool tag
encoded with macro GDIOBJ_POOL_TAG().)
This allows setting the memory protection of the kernel's resource
section as will. MmMakeKernelResourceSectionWritable() is re-implemented
around this helper.
- MiLocateKernelSections(): Fix the calculation of MiKernelResourceEndPte,
MmPoolCodeEnd and MmPteCodeEnd.
- MmMakeKernelResourceSectionWritable(): Fix PTE looping upper limit;
use MI_MAKE_HARDWARE_PTE_KERNEL to build the updated read-write PTE.
- Introduce the MmMakeKernelResourceSectionWritable() helper for
making the kernel resource memory section writable, and use it
in KeGetBugMessageText(). Indeed, this latter function patches
in place the bugcheck resource message to trim any trailing
newlines before displaying the message on screen.
See also https://github.com/osresearch/uxen/blob/83bad53/dm/introspection-win7.c#L286
that mentions it too.
This fixes bugcheck text display (e.g. the MANUALLY_INITIATED_CRASH one)
when using (at least) MSVC-built ReactOS, avoiding a Page-Fault
exception during the bugcheck.
- Cover KeGetBugMessageText() in SEH since we are accessing kernel
resources that could also be corrupted in bugcheck scenarii, and we
don't want to further bugcheck.
- Fix newline trimming loop.
- KiDoBugCheckCallbacks():
* Wrap the bugcheck CallbackRoutine call in SEH.
* Add a FIXME concerning the need of further memory validation of CurrentRecord.
- Add a FIXME concerning the need to run the bugcheck-reason callbacks
with the KbCallbackReserved1 reason, in KeBugCheckWithTf().
Mentioned in http://blog.ptsecurity.com/2012/06/customizing-blue-screen-of-death.html
"Release" builds should not BSoD on 'Freeing pool - invalid tag specified' case,
this is compatible with Windows behaviour.
Nothing changes otherwise concerning the "Debug" builds, where pool-tag mismatch
triggers a BSoD as expected.
CORE-15446
* The previous version was overcomplicated and broken and therefore disabled.
* The new version also enforces NX protection on x64.
* Now that protecting works, also protect the boot loaded images.
This allows avoiding one of the previous implementation limits:
leaked IRP not queued to a thread are now totally visible since
we look directly in the memory pool.
For now, it allows searching for pool allocations in
both paged and non paged pool.
It is based on Andreas Schuster work to identify POOL_HEADER
structures.
* Add an NDK header to define INIT_FUNCTION/INIT_SECTION globally
* Use _declspec(allocate(x)) and _declspec(code_seg(x)) on MSVC versions that support it
* Use INIT_FUNCTION on functions only and INIT_SECTION on data only (required by MSVC)
* Place INIT_FUNCTION before the return type (required by MSVC)
* Make sure declarations and implementations share the same modifiers (required by MSVC)
* Add a global linker option to suppress warnings about defined but unused INIT section
* Merge INIT section into .text in freeldr
Short: The code was suffering from an off-by-one bug (inconsistency between inclusive end exclusive end address), which could lead to freeing one page above the initialization code. This led to freeing part of the kernel import section on x64. Now it is consistently using the aligned/exclusive end address.
Long:
* Initialization sections are freed both for the boot loaded images as well as for drivers that are loaded later. Obviously the second mechanism needs to be able to run at any time, so it is not initialization code itself. For some reason someone decided though, it would be a smart idea to implement the code twice, once for the boot loaded images, once for drivers and concluding that the former was initialization code itself and had to be freed.
* Since freeing the code that frees the initialization sections, while it is doing that is not possible, it uses a "smart trick", initially skipping that range, returning its start and end to the caller and have the caller free it afterwards.
* The code was using the end address in an inconsistent way, partly aligning it to the start of the following section, sometimes pointing to the last byte that should be freed. The function that freed each chunk was assuming the latter (i.e. that the end was included in the range) and thus freed the page that contained the end address. The end address for the range that was returned to the caller was aligned to the start of the next section, and the caller used it to free the range including the following page. On x64 this was the start of the import section of ntoskrnl. How that worked on x86 I don't even want to know.
Kernel stacks that re freed, can be placed on an SLIST for quick reuse. The old code was using a member of the PFN of the last stack page as the SLIST_ENTRY. This relies on the following (non-portable) assumptions:
- A stack always has a PTE associated with it.
- This PTE has a PFN associated with it.
- The PFN has an empty field that can be re-used as an SLIST_ENTRY.
- The PFN has another field that points back to the PTE, which then can be used to get the stack base.
Specifically: On x64 the PFN field is not 16 bytes aligned, so it cannot be used as an SLIST_ENTRY. (In a "usermode kernel" the other assumptions are also invalid).
The new code does what Windows does (and which seems absolutely obvious to do): Place the SLIST_ENTRY directly on the stack.
The size is in bytes, not in pages! On x86 we got away with it, since PEB and TEB require only a single page and the 1 passed to MiInsertVadEx() was aligned up to PAGE_SIZE. On x64 this doesn't work, since the size is 2 pages.
