Stack-buffer-overflow in sao.cc:248: void apply_sao_internal<unsigned short>

[fdu-sec]

Description

Stack-buffer-overflow (/libde265/build/libde265/liblibde265.so+0x19337f) in void apply_sao_internal(de265_image*, int, int, slice_segment_header const*, int, int, int, unsigned short const*, int, unsigned short*, int)

Version

$ ./dec265 -h
 dec265  v1.0.8
--------------
usage: dec265 [options] videofile.bin
The video file must be a raw bitstream, or a stream with NAL units (option -n).

options:
  -q, --quiet       do not show decoded image
  -t, --threads N   set number of worker threads (0 - no threading)
  -c, --check-hash  perform hash check
  -n, --nal         input is a stream with 4-byte length prefixed NAL units
  -f, --frames N    set number of frames to process
  -o, --output      write YUV reconstruction
  -d, --dump        dump headers
  -0, --noaccel     do not use any accelerated code (SSE)
  -v, --verbose     increase verbosity level (up to 3 times)
  -L, --no-logging  disable logging
  -B, --write-bytestream FILENAME  write raw bytestream (from NAL input)
  -m, --measure YUV compute PSNRs relative to reference YUV
  -T, --highest-TID select highest temporal sublayer to decode
      --disable-deblocking   disable deblocking filter
      --disable-sao          disable sample-adaptive offset filter
  -h, --help        show help

Replay

git clone https://github.com/strukturag/libde265.git
cd libde265
mkdir build
cd build
cmake ../ -DCMAKE_CXX_FLAGS="-fsanitize=address"
make -j$(nproc)
./dec265/dec265 poc16

ASAN

WARNING: end_of_sub_stream_one_bit not set to 1 when it should be
WARNING: non-existing PPS referenced
WARNING: non-existing PPS referenced
=================================================================
==38055==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fff34a96b44 at pc 0x7f62be643380 bp 0x7fff34a96550 sp 0x7fff34a96540
READ of size 4 at 0x7fff34a96b44 thread T0
    #0 0x7f62be64337f in void apply_sao_internal<unsigned short>(de265_image*, int, int, slice_segment_header const*, int, int, int, unsigned short const*, int, unsigned short*, int) (/libde265/build/libde265/liblibde265.so+0x19337f)
    #1 0x7f62be6413b6 in void apply_sao<unsigned char>(de265_image*, int, int, slice_segment_header const*, int, int, int, unsigned char const*, int, unsigned char*, int) (/libde265/build/libde265/liblibde265.so+0x1913b6)
    #2 0x7f62be63f761 in apply_sample_adaptive_offset_sequential(de265_image*) (/libde265/build/libde265/liblibde265.so+0x18f761)
    #3 0x7f62be5cda5d in decoder_context::run_postprocessing_filters_sequential(de265_image*) (/libde265/build/libde265/liblibde265.so+0x11da5d)
    #4 0x7f62be5c4ecf in decoder_context::decode_some(bool*) (/libde265/build/libde265/liblibde265.so+0x114ecf)
    #5 0x7f62be5c493d in decoder_context::read_slice_NAL(bitreader&, NAL_unit*, nal_header&) (/libde265/build/libde265/liblibde265.so+0x11493d)
    #6 0x7f62be5c743e in decoder_context::decode_NAL(NAL_unit*) (/libde265/build/libde265/liblibde265.so+0x11743e)
    #7 0x7f62be5c7ab3 in decoder_context::decode(int*) (/libde265/build/libde265/liblibde265.so+0x117ab3)
    #8 0x7f62be5aee95 in de265_decode (/libde265/build/libde265/liblibde265.so+0xfee95)
    #9 0x563cdef44bc9 in main (/libde265/build/dec265/dec265+0x6bc9)
    #10 0x7f62be0e0c86 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21c86)
    #11 0x563cdef429b9 in _start (/libde265/build/dec265/dec265+0x49b9)

Address 0x7fff34a96b44 is located in stack of thread T0 at offset 308 in frame
    #0 0x7f62be5c3e8b in decoder_context::read_slice_NAL(bitreader&, NAL_unit*, nal_header&) (/libde265/build/libde265/liblibde265.so+0x113e8b)

  This frame has 5 object(s):
    [32, 33) 'continueDecoding'
    [96, 97) 'did_work'
    [160, 164) 'err'
    [224, 232) 'imgunit'
    [288, 296) 'sliceunit' <== Memory access at offset 308 overflows this variable
HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext
      (longjmp and C++ exceptions *are* supported)
SUMMARY: AddressSanitizer: stack-buffer-overflow (/libde265/build/libde265/liblibde265.so+0x19337f) in void apply_sao_internal<unsigned short>(de265_image*, int, int, slice_segment_header const*, int, int, int, unsigned short const*, int, unsigned short*, int)
Shadow bytes around the buggy address:
  0x10006694ad10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10006694ad20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10006694ad30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10006694ad40: 00 00 f1 f1 f1 f1 01 f2 f2 f2 f2 f2 f2 f2 01 f2
  0x10006694ad50: f2 f2 f2 f2 f2 f2 04 f2 f2 f2 f2 f2 f2 f2 00 f2
=>0x10006694ad60: f2 f2 f2 f2 f2 f2 f8 f2[f2]f2 00 00 00 00 00 00
  0x10006694ad70: 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 03 f2
  0x10006694ad80: f2 f2 f2 f2 f2 f2 00 00 00 00 f3 f3 f3 f3 00 00
  0x10006694ad90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10006694ada0: f1 f1 f1 f1 01 f2 f2 f2 00 00 00 00 00 00 00 00
  0x10006694adb0: 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
==38055==ABORTING

POC

https://github.com/FDU-Sec/poc/blob/main/libde265/poc16

Environment

Ubuntu 18.04.5 LTS
Clang 10.0.1
gcc 7.5.0

Credit

Peng Deng (Fudan University)

[farindk]

Should be fixed by #375