Closed
Description
Hi,
fuzzing sndfile-info with AFL++ I found a heap-buffer-overflow in in msadpcm_decode_block /home/andreaf/real/libsndfile/src/ms_adpcm.c:279
I'm on an x86-64 Ubuntu 20.04 with Clang 10.
The AddressSanitizer report is the following:
=================================================================
==24888==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x621000001238 at pc 0x0000005ebedc bp 0x7ffced651bd0 sp 0x7ffced651bc8
WRITE of size 2 at 0x621000001238 thread T0
#0 0x5ebedb in msadpcm_decode_block /home/andreaf/libsndfile/src/ms_adpcm.c:279:31
#1 0x5e9cf8 in wavlike_msadpcm_init /home/andreaf/libsndfile/src/ms_adpcm.c:171:3
#2 0x566da9 in wav_open /home/andreaf/libsndfile/src/wav.c:258:14
#3 0x4cc6d2 in psf_open_file /home/andreaf/libsndfile/src/sndfile.c:3080:13
#4 0x4caa5e in sf_open /home/andreaf/libsndfile/src/sndfile.c:359:9
#5 0x4c57dd in cart_dump /home/andreaf/libsndfile/programs/sndfile-info.c:479:14
#6 0x4c36c3 in main /home/andreaf/libsndfile/programs/sndfile-info.c:96:13
#7 0x7f114ca61bf6 in __libc_start_main /build/glibc-S9d2JN/glibc-2.27/csu/../csu/libc-start.c:310
#8 0x41b4c9 in _start (/home/andreaf/libsndfile/programs/sndfile-info+0x41b4c9)
0x621000001238 is located 0 bytes to the right of 4408-byte region [0x621000000100,0x621000001238)
allocated by thread T0 here:
#0 0x493d82 in calloc (/home/andreaf/libsndfile/programs/sndfile-info+0x493d82)
#1 0x5e90b4 in wavlike_msadpcm_init /home/andreaf/libsndfile/src/ms_adpcm.c:138:27
#2 0x566da9 in wav_open /home/andreaf/libsndfile/src/wav.c:258:14
#3 0x4cc6d2 in psf_open_file /home/andreaf/libsndfile/src/sndfile.c:3080:13
#4 0x4caa5e in sf_open /home/andreaf/libsndfile/src/sndfile.c:359:9
#5 0x4c57dd in cart_dump /home/andreaf/libsndfile/programs/sndfile-info.c:479:14
#6 0x4c36c3 in main /home/andreaf/libsndfile/programs/sndfile-info.c:96:13
#7 0x7f114ca61bf6 in __libc_start_main /build/glibc-S9d2JN/glibc-2.27/csu/../csu/libc-start.c:310
SUMMARY: AddressSanitizer: heap-buffer-overflow /home/andreaf/libsndfile/src/ms_adpcm.c:279:31 in msadpcm_decode_block
Shadow bytes around the buggy address:
0x0c427fff81f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c427fff8200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c427fff8210: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c427fff8220: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c427fff8230: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c427fff8240: 00 00 00 00 00 00 00[fa]fa fa fa fa fa fa fa fa
0x0c427fff8250: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c427fff8260: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c427fff8270: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c427fff8280: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c427fff8290: 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
==24888==ABORTING
To reproduce on git master:
export CC='clang-10 -fsanitize=address'
export CFLAGS='-g'
./configure --disable-shared
make
./programs/sndfile-info --cart ./sndfile_heap_overflow
The testcase that triggers the bug is (decompress it before):