Headline
CVE-2019-14465: Heap-based buffer overflow in the fmt_mtm_load_song() function · Issue #198 · schismtracker/schismtracker
fmt_mtm_load_song in fmt/mtm.c in Schism Tracker 20190722 has a heap-based buffer overflow.
While fuzzing Schism Tracker with Honggfuzz, I found a heap-based buffer overflow in the fmt_mtm_load_song() function, in mtm.c L139.
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==11045==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7ff6d73debd4 at pc 0x0000004b4ae4 bp 0x7ffea6d192b0 sp 0x7ffea6d18a48
WRITE of size 1 at 0x7ff6d73debd4 thread T0
#0 0x4b4ae3 in strcpy /build/llvm-toolchain-8-F3l7P1/llvm-toolchain-8-8/projects/compiler-rt/lib/asan/asan_interceptors.cc:433:5
#1 0x5c40f0 in fmt_mtm_load_song /home/fcambus/schismtracker/fmt/mtm.c:139:3
#2 0x6caa4b in song_create_load /home/fcambus/schismtracker/schism/audio_loadsave.c:224:11
#3 0x6caf4e in song_load_unchecked /home/fcambus/schismtracker/schism/audio_loadsave.c:282:12
#4 0x61dd3c in main /home/fcambus/schismtracker/schism/main.c:1132:7
#5 0x7ff6dbb9ab6a in __libc_start_main /build/glibc-KRRWSm/glibc-2.29/csu/../csu/libc-start.c:308:16
#6 0x41eb99 in _start (/home/fcambus/schismtracker/schismtracker+0x41eb99)
0x7ff6d73debd4 is located 140 bytes to the right of 168776-byte region [0x7ff6d73b5800,0x7ff6d73deb48)
allocated by thread T0 here:
#0 0x4ca73a in calloc /build/llvm-toolchain-8-F3l7P1/llvm-toolchain-8-8/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:155:3
#1 0x5fb5dc in mem_calloc /home/fcambus/schismtracker/schism/util.c:113:6
#2 0x6de326 in csf_allocate /home/fcambus/schismtracker/player/csndfile.c:98:16
#3 0x6ca557 in song_create_load /home/fcambus/schismtracker/schism/audio_loadsave.c:207:20
#4 0x6caf4e in song_load_unchecked /home/fcambus/schismtracker/schism/audio_loadsave.c:282:12
#5 0x61dd3c in main /home/fcambus/schismtracker/schism/main.c:1132:7
#6 0x7ff6dbb9ab6a in __libc_start_main /build/glibc-KRRWSm/glibc-2.29/csu/../csu/libc-start.c:308:16
SUMMARY: AddressSanitizer: heap-buffer-overflow /build/llvm-toolchain-8-F3l7P1/llvm-toolchain-8-8/projects/compiler-rt/lib/asan/asan_interceptors.cc:433:5 in strcpy
Shadow bytes around the buggy address:
0x0fff5ae73d20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fff5ae73d30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fff5ae73d40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fff5ae73d50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fff5ae73d60: 00 00 00 00 00 00 00 00 00 fa fa fa fa fa fa fa
=>0x0fff5ae73d70: fa fa fa fa fa fa fa fa fa fa[fa]fa fa fa fa fa
0x0fff5ae73d80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0fff5ae73d90: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0fff5ae73da0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0fff5ae73db0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0fff5ae73dc0: 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
==11045==ABORTING