plugin/vfspk3: prevent buffer overflow/stack smashing

This isssue:

```
netradiant/plugins/vfspk3/vfs.cpp:595:7: warning: array index 1024 is past the end of the array (which contains 1024 elements)
      [-Warray-bounds]
                                                tmppath[PATH_MAX] = '\0';
                                                ^       ~~~~~~~~
netradiant/plugins/vfspk3/vfs.cpp:587:5: note: array 'tmppath' declared here
                                char tmppath[PATH_MAX];
                                ^
netradiant/plugins/vfspk3/vfs.cpp:607:7: warning: array index 1024 is past the end of the array (which contains 1024 elements)
      [-Warray-bounds]
                                                tmppath[PATH_MAX] = '\0';
                                                ^       ~~~~~~~~
netradiant/plugins/vfspk3/vfs.cpp:587:5: note: array 'tmppath' declared here
                                char tmppath[PATH_MAX];
```

is producing this (on macOS):

```
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
    frame #0: 0x00007fff58f4f2c6 libsystem_kernel.dylib`__pthread_kill + 10
libsystem_kernel.dylib`__pthread_kill:
->  0x7fff58f4f2c6 <+10>: jae    0x7fff58f4f2d0            ; <+20>
    0x7fff58f4f2c8 <+12>: movq   %rax, %rdi
    0x7fff58f4f2cb <+15>: jmp    0x7fff58f49457            ; cerror_nocancel
    0x7fff58f4f2d0 <+20>: retq
Target 0: (netradiant) stopped.
(lldb) thread backtrace all
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
  * frame #0: 0x00007fff58f4f2c6 libsystem_kernel.dylib`__pthread_kill + 10
    frame #1: 0x00007fff5900abf1 libsystem_pthread.dylib`pthread_kill + 284
    frame #2: 0x00007fff58eb9745 libsystem_c.dylib`__abort + 144
    frame #3: 0x00007fff58eb9ff3 libsystem_c.dylib`__stack_chk_fail + 205
    frame #4: 0x000000010a8a7e59 libvfspk3.so`InitDirectory(char const*, Modules<_QERArchiveTable>&) + 7689
    frame #5: 0x00000001000e0a57 netradiant`QE_InitVFS() + 1351
    frame #6: 0x0000000100094673 netradiant`VFSModuleObserver::realise() + 19
    frame #7: 0x000000010009478a netradiant`HomePathsModuleObserver::realise() + 58
    frame #8: 0x000000010008906a netradiant`EnginePath_Realise() + 58
    frame #9: 0x00000001000d3f5f netradiant`Radiant::Radiant() + 351
    frame #10: 0x00000001000d15d1 netradiant`Radiant_Construct(ModuleServer&) + 353
    frame #11: 0x000000010008a84a netradiant`Radiant_Initialise() + 42
    frame #12: 0x0000000100088087 netradiant`main + 535
    frame #13: 0x00007fff58e143d5 libdyld.dylib`start + 1
  thread #2
    frame #0: 0x00007fff58f4abfe libsystem_kernel.dylib`__workq_kernreturn + 10
    frame #1: 0x00007fff59007636 libsystem_pthread.dylib`_pthread_wqthread + 458
    frame #2: 0x00007fff590073fd libsystem_pthread.dylib`start_wqthread + 13
  thread #3
    frame #0: 0x00007fff58f4abfe libsystem_kernel.dylib`__workq_kernreturn + 10
    frame #1: 0x00007fff59007636 libsystem_pthread.dylib`_pthread_wqthread + 458
    frame #2: 0x00007fff590073fd libsystem_pthread.dylib`start_wqthread + 13
  thread #4
    frame #0: 0x00007fff58f4abfe libsystem_kernel.dylib`__workq_kernreturn + 10
    frame #&1: 0x00007fff590076e6 libsystem_pthread.dylib`_pthread_wqthread + 634
    frame #2: 0x00007fff590073fd libsystem_pthread.dylib`start_wqthread + 13
```

diff --git a/plugins/vfspk3/vfs.cpp b/plugins/vfspk3/vfs.cpp
index ded3d048f817a5278b0dec1f05762c96339965f2..44c2ebb5290630fe13f17d1415773c27f55dc8eb 100644 (file)
--- a/plugins/vfspk3/vfs.cpp
+++ b/plugins/vfspk3/vfs.cpp
@@ -562,7 +562,7 @@ void InitDirectory( const char* directory, ArchiveModules& archiveModules ){
                                }
 
                                const char *ext = strrchr( name, '.' );
-                               char tmppath[PATH_MAX];
+                               char tmppath[PATH_MAX + 1];
 
                                if ( ext != nullptr ) {
                                        if ( is_dpk_vfs && !string_compare_nocase_upper( ext, ".dpkdir" ) ) {