Heap buffer overflow (read) while loading map in CRenderTools::RenderTilemap, render_map.cpp:390

[mmmds]

The client crashes (only with ASAN) when an invalid map (11.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"
[...]
=================================================================
==33639==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61900082f57c at pc 0x555555854a9c bp 0x7fffffffb280 sp 0x7fffffffb270
READ of size 1 at 0x61900082f57c thread T0
    #0 0x555555854a9b in CRenderTools::RenderTilemap(CTile*, int, int, float, vector4_base<float>, int, void (*)(float, int, float*, void*), void*, int, int) /home/osboxes/teeworlds/teeworlds-asan/src/game/client/render_map.cpp:390
    #1 0x5555556f7e4a in CMapLayers::OnRender() /home/osboxes/teeworlds/teeworlds-asan/src/game/client/components/maplayers.cpp:356
    #2 0x555555827989 in CGameClient::OnRender() /home/osboxes/teeworlds/teeworlds-asan/src/game/client/gameclient.cpp:611
    #3 0x5555555fce4e in CClient::Render() /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:796
    #4 0x5555555fce4e in CClient::Run() /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:2131
    #5 0x5555555d24e5 in main /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:2704
    #6 0x7ffff68e10b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
    #7 0x5555555dc48d in _start (/home/osboxes/teeworlds/teeworlds-asan/build/teeworlds+0x8848d)

0x61900082f57c is located 4 bytes to the left of 968-byte region [0x61900082f580,0x61900082f948)
allocated by thread T0 here:
    #0 0x7ffff768ebc8 in malloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dbc8)
    #1 0x555555973785 in CDataFileReader::GetDataImpl(int, int) /home/osboxes/teeworlds/teeworlds-asan/src/engine/shared/datafile.cpp:303
    #2 0x555555973785 in CDataFileReader::GetData(int) /home/osboxes/teeworlds/teeworlds-asan/src/engine/shared/datafile.cpp:341
    #3 0x5555559e6444 in CLayers::InitTilemapSkip() /home/osboxes/teeworlds/teeworlds-asan/src/game/layers.cpp:75
    #4 0x5555558398d0 in CGameClient::OnConnected() /home/osboxes/teeworlds/teeworlds-asan/src/game/client/gameclient.cpp:454
    #5 0x5555555f6755 in CClient::ProcessServerPacket(CNetChunk*) /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:1283
    #6 0x5555555f91ce in CClient::PumpNetwork() /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:1596
    #7 0x5555555f9596 in CClient::Update() /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:1766
    #8 0x5555555fc1f0 in CClient::Run() /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:2108
    #9 0x5555555d24e5 in main /home/osboxes/teeworlds/teeworlds-asan/src/engine/client/client.cpp:2704
    #10 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/game/client/render_map.cpp:390 in CRenderTools::RenderTilemap(CTile*, int, int, float, vector4_base<float>, int, void (*)(float, int, float*, void*), void*, int, int)
Shadow bytes around the buggy address:
  0x0c32800fde50: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c32800fde60: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c32800fde70: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c32800fde80: fd fd fd fd fd fd fd fd fd fd fa fa fa fa fa fa
  0x0c32800fde90: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0c32800fdea0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa[fa]
  0x0c32800fdeb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c32800fdec0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c32800fded0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c32800fdee0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c32800fdef0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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
==33639==ABORTING

Doesn't crash without ASAN.

[AssassinTee]

wasn't able to load this anymore
E datafile: invalid header data size or truncated file. data_size=2683 file_size=5720

[ChillerDragon]

This map does not error or segfault for me when running with a debug build without asan. It just loads fine and I can play.
With asan I can still reproduce the same error on Linux archlinux 6.16.6-arch1-1 at 5d68273

[2025-09-23 10:00:14][client]: connected, sending info
[2025-09-23 10:00:14][client]: loading map, map=11 wanted sha256=b27fdf34fa3f142e143936b03a8a84620e62a716686c8ca995f1b1a195d3495a crc=8f8bdcc8
[2025-09-23 10:00:14][datafile]: loading. filename='maps/11.map'
[2025-09-23 10:00:14][datafile]: could not open 'maps/11.map'
[2025-09-23 10:00:14][datafile]: loading. filename='downloadedmaps/11_b27fdf34fa3f142e143936b03a8a84620e62a716686c8ca995f1b1a195d3495a.map'
[2025-09-23 10:00:14][datafile]: allocsize=3328
[2025-09-23 10:00:14][datafile]: readsize=3012
[2025-09-23 10:00:14][datafile]: swaplen=3032
[2025-09-23 10:00:14][datafile]: item_size=2716
[2025-09-23 10:00:14][datafile]: loading done. datafile='downloadedmaps/11_b27fdf34fa3f142e143936b03a8a84620e62a716686c8ca995f1b1a195d3495a.map'
[2025-09-23 10:00:14][datafile]: loading data index=9 size=516 uncompressed=1172
[2025-09-23 10:00:14][datafile]: loading data index=10 size=291 uncompressed=972
[2025-09-23 10:00:14][datafile]: loading data index=11 size=519 uncompressed=1984
[2025-09-23 10:00:14][datafile]: loading data index=12 size=206 uncompressed=368
[2025-09-23 10:00:14][client]: loaded map 'downloadedmaps/11_b27fdf34fa3f142e143936b03a8a84620e62a716686c8ca995f1b1a195d3495a.map'
[2025-09-23 10:00:14][client/network]: loading done
[2025-09-23 10:00:14][datafile]: loading data index=8 size=249 uncompressed=968
[2025-09-23 10:00:14][datafile]: loading data index=0 size=22 uncompressed=14
[2025-09-23 10:00:14][datafile]: loading data index=1 size=19 uncompressed=11
[2025-09-23 10:00:14][datafile]: loading data index=2 size=18 uncompressed=10
[2025-09-23 10:00:14][datafile]: loading data index=3 size=12 uncompressed=4
[2025-09-23 10:00:14][datafile]: loading data index=4 size=69 uncompressed=152
[2025-09-23 10:00:14][datafile]: loading data index=5 size=627 uncompressed=2432
[2025-09-23 10:00:14][datafile]: loading data index=6 size=59 uncompressed=152
[2025-09-23 10:00:14][datafile]: loading data index=7 size=76 uncompressed=152

=================================================================
==287765==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7d166e8c3e7c at pc 0x5584bd60820a bp 0x7fff78801030 sp 0x7fff78801028
READ of size 1 at 0x7d166e8c3e7c thread T0
    #0 0x5584bd608209 in CRenderTools::RenderTilemap(CTile const*, int, int, float, vector4_base<float>, int, void (*)(float, int, float*, void*), void*, int, int) /home/chiller/Desktop/gaming/teeworlds/src/game/client/render_map.cpp:389:36
    #1 0x5584bd38cf9a in CMapLayers::OnRender() /home/chiller/Desktop/gaming/teeworlds/src/game/client/components/maplayers.cpp:359:22
    #2 0x5584bd59a42f in CGameClient::OnRender() /home/chiller/Desktop/gaming/teeworlds/src/game/client/gameclient.cpp:614:28
    #3 0x5584bd159b44 in CClient::Render() /home/chiller/Desktop/gaming/teeworlds/src/engine/client/client.cpp:786:17
    #4 0x5584bd182ef2 in CClient::Run() /home/chiller/Desktop/gaming/teeworlds/src/engine/client/client.cpp:2120:6
    #5 0x5584bd192cbf in main /home/chiller/Desktop/gaming/teeworlds/src/engine/client/client.cpp:2702:11
    #6 0x7f866f227674 in __libc_start_call_main /usr/src/debug/glibc/glibc/csu/../sysdeps/nptl/libc_start_call_main.h:58:16
    #7 0x7f866f227728 in __libc_start_main /usr/src/debug/glibc/glibc/csu/../csu/libc-start.c:360:3
    #8 0x5584bcfd9554 in _start (/home/chiller/Desktop/gaming/teeworlds/build-san/teeworlds+0x4bc554) (BuildId: 0296ee92775973a0733886e6dd2a66c871f6f674)

0x7d166e8c3e7c is located 4 bytes before 968-byte region [0x7d166e8c3e80,0x7d166e8c4248)
allocated by thread T0 here:
    #0 0x5584bd0da735 in malloc (/home/chiller/Desktop/gaming/teeworlds/build-san/teeworlds+0x5bd735) (BuildId: 0296ee92775973a0733886e6dd2a66c871f6f674)
    #1 0x5584bd9149dd in mem_alloc /home/chiller/Desktop/gaming/teeworlds/src/base/system.c:330:9
    #2 0x5584bd8498df in CDataFileReader::GetDataImpl(int, int) /home/chiller/Desktop/gaming/teeworlds/src/engine/shared/datafile.cpp:303:47
    #3 0x5584bd84ae9d in CDataFileReader::GetData(int) /home/chiller/Desktop/gaming/teeworlds/src/engine/shared/datafile.cpp:341:9
    #4 0x5584bd891bd7 in CMap::GetData(int) /home/chiller/Desktop/gaming/teeworlds/src/engine/shared/map.cpp:15:55
    #5 0x5584bd94895b in CLayers::InitTilemapSkip() /home/chiller/Desktop/gaming/teeworlds/src/game/layers.cpp:75:37
    #6 0x5584bd947488 in CLayers::Init(IKernel*, IMap*) /home/chiller/Desktop/gaming/teeworlds/src/game/layers.cpp:23:2
    #7 0x5584bd592a6f in CGameClient::OnConnected() /home/chiller/Desktop/gaming/teeworlds/src/game/client/gameclient.cpp:455:11
    #8 0x5584bd167bf9 in CClient::ProcessServerPacket(CNetChunk*) /home/chiller/Desktop/gaming/teeworlds/src/engine/client/client.cpp:1270:18
    #9 0x5584bd170007 in CClient::PumpNetwork() /home/chiller/Desktop/gaming/teeworlds/src/engine/client/client.cpp:1586:4
    #10 0x5584bd175b27 in CClient::Update() /home/chiller/Desktop/gaming/teeworlds/src/engine/client/client.cpp:1751:2
    #11 0x5584bd181c40 in CClient::Run() /home/chiller/Desktop/gaming/teeworlds/src/engine/client/client.cpp:2095:4
    #12 0x5584bd192cbf in main /home/chiller/Desktop/gaming/teeworlds/src/engine/client/client.cpp:2702:11
    #13 0x7f866f227674 in __libc_start_call_main /usr/src/debug/glibc/glibc/csu/../sysdeps/nptl/libc_start_call_main.h:58:16
    #14 0x7f866f227728 in __libc_start_main /usr/src/debug/glibc/glibc/csu/../csu/libc-start.c:360:3
    #15 0x5584bcfd9554 in _start (/home/chiller/Desktop/gaming/teeworlds/build-san/teeworlds+0x4bc554) (BuildId: 0296ee92775973a0733886e6dd2a66c871f6f674)

SUMMARY: AddressSanitizer: heap-buffer-overflow /home/chiller/Desktop/gaming/teeworlds/src/game/client/render_map.cpp:389:36 in CRenderTools::RenderTilemap(CTile const*, int, int, float, vector4_base<float>, int, void (*)(float, int, float*, void*), void*, int, int)
Shadow bytes around the buggy address:
  0x7d166e8c3b80: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x7d166e8c3c00: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x7d166e8c3c80: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x7d166e8c3d00: fd fd fd fd fd fd fd fd fd fd fa fa fa fa fa fa
  0x7d166e8c3d80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x7d166e8c3e00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa[fa]
  0x7d166e8c3e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x7d166e8c3f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x7d166e8c3f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x7d166e8c4000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x7d166e8c4080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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
==287765==ABORTING