[Bug 49753] New: server_ioctl_file: Syscall param writev(vector[...]) points to uninitialised byte(s)

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=49753

Bug ID: 49753
           Summary: server_ioctl_file: Syscall param writev(vector[...])
                    points to uninitialised byte(s)
           Product: Wine
           Version: 5.16
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: ntdll
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 68056
  --> https://bugs.winehq.org/attachment.cgi?id=68056
Valgrind output.

Occurs as of commit 5bb27d1edb2.  Valgrind output attached.

Full valgrind trace:

==26644== Syscall param writev(vector[...]) points to uninitialised byte(s)
==26644==    at 0x4322F07: writev (writev.c:26)
==26644==    by 0x48530E2: send_request (server.c:213)
==26644==    by 0x4853224: server_call_unlocked (server.c:273)
==26644==    by 0x48722CF: virtual_locked_server_call (virtual.c:3015)
==26644==    by 0x483F666: server_ioctl_file (file.c:4730)
==26644==    by 0x484143A: NtDeviceIoControlFile (file.c:5561)
==26644==    by 0x4838F6E: get_mountmgr_fs_info (file.c:1975)
==26644==    by 0x4842E3A: NtQueryVolumeInformationFile (file.c:6380)
==26644==    by 0x482F1BD: __wine_syscall_dispatcher (in
/home/rofl/wine32-build-debug-nomingw/dlls/ntdll/ntdll.so)
==26644==    by 0x7BC32F9B: NtQueryVolumeInformationFile (in
/home/rofl/wine32-build-debug-nomingw/dlls/ntdll/ntdll.dll.so)
==26644==    by 0x7B0403EB: GetFileInformationByHandle (file.c:2930)
==26644==    by 0x536D262: MSVCRT__fstat64 (file.c:1781)
==26644==    by 0x536D4B5: MSVCRT__fstat32 (file.c:1839)
==26644==    by 0x512498B: fstat (stat.h:222)
==26644==    by 0x5128EC5: update_wineprefix (wineboot.c:1437)
==26644==    by 0x5129BF7: main (wineboot.c:1671)