Heap buffer overflow (read) while loading map in CMapLayers::LoadEnvPoints, maplayers.cpp:164

[mmmds]

The client crashes when an invalid map (8.map.zip) is loaded. Such a map can be delivered to the client by a malicious server.

Tested on Ubuntu 20.04 x86_64, Teeworlds version: f35da54b6f2c5f9fd4bbd4559f887ccf8f8cc526

Compilation with ASAN:

export CXXFLAGS="-ggdb -O0 -fsanitize=address -fno-omit-frame-pointer"
export CFLAGS="-ggdb -O0 -fsanitize=address -fno-omit-frame-pointer"
cmake ..
make

Run and connect to a server that delivers an invalid map:

./teeworlds "connect 127.0.0.1" "gfx_fullscreen 0" "gfx_screen_height 240" "gfx_screen_width 360"
[...]
=================================================================
==33556==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61f0000df180 at pc 0x5555556faf77 bp 0x7ffffffd8e10 sp 0x7ffffffd8e00
READ of size 88 at 0x61f0000df180 thread T0
    #0 0x5555556faf76 in array<CEnvPoint, allocator_default<CEnvPoint> >::add(CEnvPoint const&) /home/osboxes/teeworlds/teeworlds-asan/src/base/tl/array.h:171
    #1 0x5555556faf76 in CMapLayers::LoadEnvPoints(CLayers const*, array<CEnvPoint, allocator_default<CEnvPoint> >&) /home/osboxes/teeworlds/teeworlds-asan/src/game/client/components/maplayers.cpp:164
    #2 0x5555556fcf3b in CMapLayers::OnMapLoad() /home/osboxes/teeworlds/teeworlds-asan/src/game/client/components/maplayers.cpp:117
    #3 0x555555839981 in CGameClient::OnConnected() /home/osboxes/teeworlds/teeworlds-asan/src/game/client/gameclient.cpp:459
    #4 0x5555555f6755 in CClient::ProcessServerPacket(CNetChunk*) /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:1283
    #5 0x5555555f91ce in CClient::PumpNetwork() /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:1596
    #6 0x5555555f9596 in CClient::Update() /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:1766
    #7 0x5555555fc1f0 in CClient::Run() /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:2108
    #8 0x5555555d24e5 in main /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:2704
    #9 0x7ffff68e10b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
    #10 0x5555555dc48d in _start (/home/osboxes/teeworlds/teeworlds-asan/build/teeworlds+0x8848d)

0x61f0000df180 is located 0 bytes to the right of 3328-byte region [0x61f0000de480,0x61f0000df180)
allocated by thread T0 here:
    #0 0x7ffff768ebc8 in malloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dbc8)
    #1 0x55555597188f in CDataFileReader::Open(IStorage*, char const*, int) /home/osboxes/teeworlds/teeworlds-asan/src/engine/shared/datafile.cpp:151
    #2 0x555555995754 in CMap::Load(char const*, IStorage*) /home/osboxes/teeworlds/teeworlds-asan/src/engine/shared/map.cpp:34
    #3 0x5555555f0c15 in CClient::LoadMap(char const*, char const*, SHA256_DIGEST const*, unsigned int) /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:807
    #4 0x5555555f7c58 in CClient::ProcessServerPacket(CNetChunk*) /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:1251
    #5 0x5555555f91ce in CClient::PumpNetwork() /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:1596
    #6 0x5555555f9596 in CClient::Update() /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:1766
    #7 0x5555555fc1f0 in CClient::Run() /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:2108
    #8 0x5555555d24e5 in main /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:2704
    #9 0x7ffff68e10b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)

SUMMARY: AddressSanitizer: heap-buffer-overflow /home/osboxes/teeworlds/teeworlds-asan/src/base/tl/array.h:171 in array<CEnvPoint, allocator_default<CEnvPoint> >::add(CEnvPoint const&)
Shadow bytes around the buggy address:
  0x0c3e80013de0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c3e80013df0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c3e80013e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c3e80013e10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c3e80013e20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c3e80013e30:[fa]fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c3e80013e40: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c3e80013e50: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c3e80013e60: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c3e80013e70: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c3e80013e80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07 
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
  Shadow gap:              cc
==33556==ABORTING

Compilation without ASAN:

export CXXFLAGS="-ggdb -O0"
export CFLAGS="-ggdb -O0"
cmake ..
make

Run and connect to a server that delivers an invalid map:

./teeworlds "connect 127.0.0.1" "gfx_fullscreen 0" "gfx_screen_height 240" "gfx_screen_width 360"
[...]
Segmentation fault (core dumped)