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ntoskrnl.exe: Protect relocated pages one at a time. 

Blindwrite 7's ezplay.sys has sections which are consecutive in memory but not
page aligned.  Thus changing the protection to PROT_READWRITE one section at a
time has the effect that old_prot for all sections but the first is set to
PROT_READWRITE (actually, PROT_WRITECOPY), causing us to restore the wrong
protection and the driver to crash in its entry point.

To fix this, protect and unprotect one page at a time while processing it, i.e.
essentially revert 6c0a8c359.  To avoid reintroducing bug 28254, protect two
pages at a time instead of just one.

Signed-off-by: Zebediah Figura <z.figura12@gmail.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
This commit is contained in:
Zebediah Figura 2020-05-02 20:55:54 -05:00 committed by Alexandre Julliard
parent 7eef40d444
commit 22dfb0df10
1 changed files with 12 additions and 29 deletions
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41
dlls/ntoskrnl.exe/ntoskrnl.c
View File

@ -3378,16 +3378,13 @@ static inline void *get_rva( HMODULE module, DWORD va )
return (void *)((char *)module + va);
}
/* Copied from ntdll with checks for page alignment and characteristics removed */
static NTSTATUS perform_relocations( void *module, SIZE_T len )
static NTSTATUS perform_relocations( void *module, SIZE_T len, ULONG page_size )
{
IMAGE_NT_HEADERS *nt;
char *base;
IMAGE_BASE_RELOCATION *rel, *end;
const IMAGE_DATA_DIRECTORY *relocs;
const IMAGE_SECTION_HEADER *sec;
INT_PTR delta;
ULONG protect_old[96], i;
nt = RtlImageNtHeader( module );
base = (char *)nt->OptionalHeader.ImageBase;
@ -3406,19 +3403,6 @@ static NTSTATUS perform_relocations( void *module, SIZE_T len )
if (!relocs->Size) return STATUS_SUCCESS;
if (!relocs->VirtualAddress) return STATUS_CONFLICTING_ADDRESSES;
if (nt->FileHeader.NumberOfSections > ARRAY_SIZE( protect_old ))
return STATUS_INVALID_IMAGE_FORMAT;
sec = (const IMAGE_SECTION_HEADER *)((const char *)&nt->OptionalHeader +
nt->FileHeader.SizeOfOptionalHeader);
for (i = 0; i < nt->FileHeader.NumberOfSections; i++)
{
void *addr = get_rva( module, sec[i].VirtualAddress );
SIZE_T size = sec[i].SizeOfRawData;
NtProtectVirtualMemory( NtCurrentProcess(), &addr,
&size, PAGE_READWRITE, &protect_old[i] );
}
TRACE( "relocating from %p-%p to %p-%p\n",
base, base + len, module, (char *)module + len );
@ -3428,23 +3412,22 @@ static NTSTATUS perform_relocations( void *module, SIZE_T len )
while (rel < end - 1 && rel->SizeOfBlock)
{
void *page = get_rva( module, rel->VirtualAddress );
DWORD old_prot;
if (rel->VirtualAddress >= len)
{
WARN( "invalid address %p in relocation %p\n", get_rva( module, rel->VirtualAddress ), rel );
return STATUS_ACCESS_VIOLATION;
}
rel = LdrProcessRelocationBlock( get_rva( module, rel->VirtualAddress ),
(rel->SizeOfBlock - sizeof(*rel)) / sizeof(USHORT),
(USHORT *)(rel + 1), delta );
if (!rel) return STATUS_INVALID_IMAGE_FORMAT;
}
for (i = 0; i < nt->FileHeader.NumberOfSections; i++)
{
void *addr = get_rva( module, sec[i].VirtualAddress );
SIZE_T size = sec[i].SizeOfRawData;
NtProtectVirtualMemory( NtCurrentProcess(), &addr,
&size, protect_old[i], &protect_old[i] );
/* Relocation entries may hang over the end of the page, so we need to
* protect two pages. */
VirtualProtect( page, page_size * 2, PAGE_READWRITE, &old_prot );
rel = LdrProcessRelocationBlock( page, (rel->SizeOfBlock - sizeof(*rel)) / sizeof(USHORT),
(USHORT *)(rel + 1), delta );
VirtualProtect( page, page_size * 2, old_prot, &old_prot );
if (!rel) return STATUS_INVALID_IMAGE_FORMAT;
}
return STATUS_SUCCESS;
@ -3475,7 +3458,7 @@ static HMODULE load_driver_module( const WCHAR *name )
if (nt->OptionalHeader.SectionAlignment < info.PageSize ||
!(nt->FileHeader.Characteristics & IMAGE_FILE_DLL))
{
status = perform_relocations(module, nt->OptionalHeader.SizeOfImage);
status = perform_relocations( module, nt->OptionalHeader.SizeOfImage, info.PageSize );
if (status != STATUS_SUCCESS)
goto error;