Libav fuzzing starts getting heap-buffer-overflow pretty quickly. It doesn't seem to be a problem in libav but in libav_fuzzer.
==9==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x611000008320 at pc 0x0000017a3725 bp 0x7ffd5acb0eb0 sp 0x7ffd5acb0ea8
READ of size 4 at 0x611000008320 thread T0
#0 0x17a3724 in get_bits /src/libav/libavcodec/get_bits.h:232:5
#1 0x17a3724 in mp_decode_layer3 /src/libav/libavcodec/mpegaudiodec_template.c:1492
#2 0x17a3724 in mp_decode_frame /src/libav/libavcodec/mpegaudiodec_template.c:1549
#3 0x178e4d3 in decode_frame /src/libav/libavcodec/mpegaudiodec_template.c:1646:11
#4 0x1df71b4 in avcodec_decode_audio4 /src/libav/libavcodec/utils.c:1638:15
#5 0x22f578a in LLVMFuzzerTestOneInput (/src/libav/libav_fuzzer+0x22f578a)
#6 0x4ff8cc in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) /src/Fuzzer/FuzzerLoop.cpp:490:13
#7 0x4ff100 in fuzzer::Fuzzer::RunOne(unsigned char const*, unsigned long) /src/Fuzzer/FuzzerLoop.cpp:446:3
#8 0x4ff982 in fuzzer::Fuzzer::RunOneAndUpdateCorpus(unsigned char const*, unsigned long) /src/Fuzzer/FuzzerLoop.cpp:467:7
#9 0x500e87 in fuzzer::Fuzzer::MutateAndTestOne() /src/Fuzzer/FuzzerLoop.cpp:682:5
#10 0x5013f7 in fuzzer::Fuzzer::Loop() /src/Fuzzer/FuzzerLoop.cpp:770:5
#11 0x4fa4e8 in fuzzer::FuzzerDriver(int*, char***, int (*)(unsigned char const*, unsigned long)) /src/Fuzzer/FuzzerDriver.cpp:416:5
#12 0x4f8a60 in main /src/Fuzzer/FuzzerMain.cpp:21:10
#13 0x7f66d754b82f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
#14 0x4245c8 in _start (/src/libav/libav_fuzzer+0x4245c8)
0x611000008320 is located 1 bytes to the right of 223-byte region [0x611000008240,0x61100000831f)
allocated by thread T0 here:
#0 0x4f5e40 in operator new[](unsigned long) (/src/libav/libav_fuzzer+0x4f5e40)
#1 0x4ff86d in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) /src/Fuzzer/FuzzerLoop.cpp:483:39
SUMMARY: AddressSanitizer: heap-buffer-overflow /src/libav/libavcodec/get_bits.h:232:5 in get_bits
Shadow bytes around the buggy address:
0x0c227fff9010: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c227fff9020: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c227fff9030: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c227fff9040: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
0x0c227fff9050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c227fff9060: 00 00 00 07[fa]fa fa fa fa fa fa fa fa fa fa fa
0x0c227fff9070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c227fff9080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fa fa
0x0c227fff9090: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
0x0c227fff90a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c227fff90b0: 00 00 00 00 00 00 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
Heap right redzone: fb
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack partial redzone: f4
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
==9==ABORTING
Libav fuzzing starts getting heap-buffer-overflow pretty quickly. It doesn't seem to be a problem in libav but in libav_fuzzer.