[Bug 4456] New: Segfault on any filesystem access to VFAT mounts

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=4456

Summary: Segfault on any filesystem access to VFAT mounts
           Product: Wine
           Version: 0.9.5.
          Platform: PC-x86-64
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: critical
          Priority: P4
         Component: wine-files
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

Any application running on wine (including winefile) segfaults on read access to
any VFAT filesystem, be it directly through a dosdevices link, or indirectly
through the z: root path.

This issue has been consistently present in wine versions 0.9.2 through 0.9.5 on
a Gentoo AMD64, with any FAT32 partition, for me as well as a few other x86_64
users.

Bug is limited to VFAT filesystems only. Other filesystems (including NTFS) work
properly with wine.

Output on attempting to browse a VFAT filesystem in winefile :-

wine: Unhandled page fault on read access to 0x00000000 at address (nil) (thread
0009), starting debugger...
WineDbg starting on pid 0x8
Unhandled exception: page fault on read access to 0x00000000 in 32-bit code
(0x00000000).
In 32 bit mode.
Register dump:
 CS:0023 SS:002b DS:002b ES:002b FS:006b GS:0063
 EIP:00000000 ESP:55beb5b4 EBP:82187201 EFLAGS:00010217(   - 00      RIAP1C)
 EAX:00000000 EBX:00000000 ECX:55744bc0 EDX:8019519e
 ESI:fffffff7 EDI:00000000
Stack dump:
0x55beb5b4:  00000000 43777fe2 00000000 00000000
0x55beb5c4:  00000000 43777fe0 00000000 2d4cae00
0x55beb5d4:  00000000 00000010 00000000 82187201
0x55beb5e4:  00000000 00000000 00000000 00000000
0x55beb5f4:  00000000 00000000 00000000 00000000
0x55beb604:  00000000 801217a3 ffffffff 00000246
Backtrace:
=>1 0x00000000 (0x00000000)
  2 0x00000000 (0x00000000)
0x00000000: addb        %al,0x0(%eax)
Modules:
Module  Address                 Debug info      Name (66 modules)
ELF     0x55555000-5556c000     Deferred        ld-linux.so.2
ELF     0x5556e000-55576000     Deferred        libnss_compat.so.2
ELF     0x55576000-5558b000     Deferred        libnsl.so.1
ELF     0x5558b000-55595000     Deferred        libnss_nis.so.2
ELF     0x55597000-555b1000     Deferred        libwine.so.1
ELF     0x555b1000-555c3000     Deferred        libpthread.so.0
ELF     0x555c3000-556da000     Deferred        libc.so.6
ELF     0x556da000-556de000     Deferred        libdl.so.2
ELF     0x556df000-55748000     Deferred        ntdll<elf>
  -PE  0x556f0000-55748000     \               ntdll
ELF     0x55748000-5583e000     Deferred        libwine_unicode.so.1
ELF     0x5583e000-55861000     Deferred        libm.so.6
ELF     0x55861000-55870000     Deferred        libz.so.1
ELF     0x55872000-55889000     Deferred        version<elf>
  -PE  0x55880000-55889000     \               version
ELF     0x55889000-5588b000     Deferred        libnvidia-tls.so.1
ELF     0x5588b000-55895000     Deferred        libnss_files.so.2
ELF     0x55895000-5589e000     Deferred        libsm.so.6
ELF     0x559b0000-55a9c000     Deferred        kernel32<elf>
  -PE  0x559d0000-55a9c000     \               kernel32
ELF     0x55a9c000-55ad7000     Deferred        winefile<elf>
  -PE  0x55ab0000-55ad7000     \               winefile
ELF     0x55ad7000-55add000     Deferred        libxxf86dga.so.1
ELF     0x55add000-55ae0000     Deferred        xlcdef.so.2
ELF     0x55bf0000-55c9a000     Deferred        shell32<elf>
  -PE  0x55c10000-55c9a000     \               shell32
ELF     0x55c9a000-55d1a000     Deferred        gdi32<elf>
  -PE  0x55cb0000-55d1a000     \               gdi32
ELF     0x55d1a000-55d50000     Deferred        advapi32<elf>
  -PE  0x55d30000-55d50000     \               advapi32
ELF     0x55d50000-55e5a000     Deferred        user32<elf>
  -PE  0x55d70000-55e5a000     \               user32
ELF     0x55e5a000-55ef1000     Deferred        comctl32<elf>
  -PE  0x55e60000-55ef1000     \               comctl32
ELF     0x55ef1000-55f83000     Deferred        comdlg32<elf>
  -PE  0x55f00000-55f83000     \               comdlg32
ELF     0x55f83000-55fa8000     Deferred        winspool<elf>
  -PE  0x55f90000-55fa8000     \               winspool
ELF     0x55fa8000-55fc3000     Deferred        mpr<elf>
  -PE  0x55fb0000-55fc3000     \               mpr
ELF     0x55fc3000-55fd7000     Deferred        lz32<elf>
  -PE  0x55fd0000-55fd7000     \               lz32
ELF     0x55fd7000-55fdc000     Deferred        libxxf86vm.so.1
ELF     0x560f0000-5610d000     Deferred        ximcp.so.2
ELF     0x5610d000-56115000     Deferred        libxrender.so.1
ELF     0x5611a000-56189000     Deferred        libfreetype.so.6
ELF     0x56189000-561b0000     Deferred        libfontconfig.so.1
ELF     0x561b0000-561d0000     Deferred        libexpat.so.0
ELF     0x561d0000-56240000     Deferred        winex11<elf>
  -PE  0x561e0000-56240000     \               winex11
ELF     0x56240000-56258000     Deferred        libice.so.6
ELF     0x56258000-56266000     Deferred        libxext.so.6
ELF     0x56266000-56330000     Deferred        libx11.so.6
ELF     0x56330000-563b3000     Deferred        libgl.so.1
ELF     0x563b3000-56b70000     Deferred        libglcore.so.1
ELF     0x56b70000-56b8a000     Deferred        imm32<elf>
  -PE  0x56b80000-56b8a000     \               imm32
ELF     0x56bb4000-56bbd000     Deferred        libxcursor.so.1
ELF     0x56bbd000-56bed000     Deferred        uxtheme<elf>
  -PE  0x56bd0000-56bed000     \               uxtheme
ELF     0x574e2000-574f6000     Deferred        msimg32<elf>
  -PE  0x574f0000-574f6000     \               msimg32
PE      0x65f00000-65fc2000     Deferred        ole32
PE      0x70bd0000-70c35000     Deferred        shlwapi
PE      0x78000000-78040000     Deferred        msvcrt
ELF     0x7bf00000-7bf03000     Deferred        <wine-loader>
Threads:
process  tid      prio (all id:s are in hex)
00000008 (D) c:\windows\system32\winefile.exe
        00000009    0 <==
WineDbg terminated on pid 0x8