[Bug 47878] New: VirtualProtect across page boundaries does not work

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=47878

Bug ID: 47878
           Summary: VirtualProtect across page boundaries does not work
           Product: Wine
           Version: unspecified
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: kernel32
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Official VirtualProtect documentation states:

The size of the region whose access protection attributes are to be changed, in
bytes. The region of affected pages includes all pages containing one or more
bytes in the range from the lpAddress parameter to (lpAddress+dwSize). This
means that a 2-byte range straddling a page boundary causes the protection
attributes of both pages to be changed.

This however is not replicated in Wine as only the first page will have its
protection changed and any pages after that resulting from the dwSize crossing
the boundary will not be affected.

[Bug 47878] VirtualProtect across page boundaries does not work

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=47878

--- Comment #1 from Alexandre Julliard  ---
Where do you see that? Do you have a test case?

[Bug 47878] VirtualProtect across page boundaries does not work

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=47878

--- Comment #2 from [e-mail] ---
It's kinda hard to reproduce. Basically, I was trying to install Median XL
Sigma mod over Diablo 2 and run it over Wine. It requires manually extracting
the installer ( the installer itself doesn't work on wine ) and applying the
file changes by myself. The mod works by hijacking a dll that is put aside the
original exe and applying a list of patches to the binary. It works by running
a VirtualProtect with 0x40 prot, doing WriteProcessMemory and running
VirtualProtect with old prot. It crashes on only one patch which is applied to
an offset ending with 0xFFD, and 4 bytes of size. I confirmed the bug by
changing the patch to 0xFFC after which it started working flawlessly.

If needed, I can try and prepare the install for someone so you can reproduce.