A stack-buffer-overflow exists in libde265 v1.0.8 via fallback-motion.cc in function put_epel_hv_fallback when running program dec265.
Hello,
A stack-buffer-overflow  has occurred when running program dec265
System info：
Ubuntu 20.04.1 : clang 10.0.0 , gcc 9.3.0



Dec265 v1.0.8

[poc (4).zip](https://github.com/strukturag/libde265/files/6710061/poc.4.zip)




Verification steps：
1.Get the source code of libde265
2.Compile 

```
cd libde265
mkdir build && cd build
cmake ../ -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_CXX_FLAGS="fsanitize=address"
make -j 32
``` 
3.run dec265

```
./dec265 poc 
```

asan info

```
=================================================================
==1262407==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffeacbd65e3 at pc 0x7ff9ff7de308 bp 0x7ffeacbd3f00 sp 0x7ffeacbd3ef0
READ of size 2 at 0x7ffeacbd65e3 thread T0
    #0 0x7ff9ff7de307 in void put_epel_hv_fallback<unsigned short>(short*, long, unsigned short const*, long, int, int, int, int, short*, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/fallback-motion.cc:352
    #1 0x7ff9ff830067 in acceleration_functions::put_hevc_epel_hv(short*, long, void const*, long, int, int, int, int, short*, int) const /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/acceleration.h:328
    #2 0x7ff9ff830067 in void mc_chroma<unsigned char>(base_context const*, seq_parameter_set const*, int, int, int, int, short*, int, unsigned char const*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/motion.cc:254
    #3 0x7ff9ff8262ab in generate_inter_prediction_samples(base_context*, slice_segment_header const*, de265_image*, int, int, int, int, int, int, int, PBMotion const*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/motion.cc:388
    #4 0x7ff9ff828626 in decode_prediction_unit(base_context*, slice_segment_header const*, de265_image*, PBMotionCoding const&, int, int, int, int, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/motion.cc:2107
    #5 0x7ff9ff89c8aa in read_coding_unit(thread_context*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:4314
    #6 0x7ff9ff8a48f2 in read_coding_quadtree(thread_context*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:4652
    #7 0x7ff9ff8a4e43 in read_coding_quadtree(thread_context*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:4638
    #8 0x7ff9ff8a4ace in read_coding_quadtree(thread_context*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:4645
    #9 0x7ff9ff8a4db9 in read_coding_quadtree(thread_context*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:4641
    #10 0x7ff9ff8a6564 in decode_substream(thread_context*, bool, bool) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:4741
    #11 0x7ff9ff8a8ddb in read_slice_segment_data(thread_context*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:5054
    #12 0x7ff9ff78dd75 in decoder_context::decode_slice_unit_sequential(image_unit*, slice_unit*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/decctx.cc:843
    #13 0x7ff9ff790c0f in decoder_context::decode_slice_unit_parallel(image_unit*, slice_unit*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/decctx.cc:945
    #14 0x7ff9ff791715 in decoder_context::decode_some(bool*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/decctx.cc:730
    #15 0x7ff9ff7949bb in decoder_context::read_slice_NAL(bitreader&, NAL_unit*, nal_header&) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/decctx.cc:688
    #16 0x7ff9ff795839 in decoder_context::decode_NAL(NAL_unit*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/decctx.cc:1230
    #17 0x7ff9ff796e1e in decoder_context::decode(int*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/decctx.cc:1318
    #18 0x5573510028fd in main /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/dec265/dec265.cc:764
    #19 0x7ff9ff2e50b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
    #20 0x55735100576d in _start (/home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/out/dec265-afl+++0xa76d)

Address 0x7ffeacbd65e3 is located in stack of thread T0 at offset 9315 in frame
    #0 0x7ff9ff82e67f in void mc_chroma<unsigned char>(base_context const*, seq_parameter_set const*, int, int, int, int, short*, int, unsigned char const*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/motion.cc:174

  This frame has 2 object(s):
    [32, 9120) 'mcbuffer' (line 200)
    [9392, 14752) 'padbuf' (line 222) <== Memory access at offset 9315 underflows this variable
HINT: this may be a false positive if your program uses some custom stack unwind mechanism, swapcontext or vfork
      (longjmp and C++ exceptions *are* supported)
SUMMARY: AddressSanitizer: stack-buffer-overflow /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/fallback-motion.cc:352 in void put_epel_hv_fallback<unsigned short>(short*, long, unsigned short const*, long, int, int, int, int, short*, int)
Shadow bytes around the buggy address:
  0x100055972c60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972c70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972c90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972ca0: 00 00 00 00 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2
=>0x100055972cb0: f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2[f2]f2 f2 f2
  0x100055972cc0: f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 00 00 00
  0x100055972cd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972ce0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972cf0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972d00: 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
==1262407==ABORTING


```











stack-buffer-overflow in fallback-motion.cc when decoding file
This is a GitHub Issue
repo:libde265
owner:strukturag
Title : stack-buffer-overflow in fallback-motion.cc when decoding file
Issue date:

--- start body ---
Hello,
A stack-buffer-overflow  has occurred when running program dec265
System info：
Ubuntu 20.04.1 : clang 10.0.0 , gcc 9.3.0



Dec265 v1.0.8

[poc (4).zip](https://github.com/strukturag/libde265/files/6710061/poc.4.zip)




Verification steps：
1.Get the source code of libde265
2.Compile 

```
cd libde265
mkdir build && cd build
cmake ../ -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_CXX_FLAGS="fsanitize=address"
make -j 32
``` 
3.run dec265

```
./dec265 poc 
```

asan info

```
=================================================================
==1262407==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffeacbd65e3 at pc 0x7ff9ff7de308 bp 0x7ffeacbd3f00 sp 0x7ffeacbd3ef0
READ of size 2 at 0x7ffeacbd65e3 thread T0
    #0 0x7ff9ff7de307 in void put_epel_hv_fallback<unsigned short>(short*, long, unsigned short const*, long, int, int, int, int, short*, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/fallback-motion.cc:352
    #1 0x7ff9ff830067 in acceleration_functions::put_hevc_epel_hv(short*, long, void const*, long, int, int, int, int, short*, int) const /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/acceleration.h:328
    #2 0x7ff9ff830067 in void mc_chroma<unsigned char>(base_context const*, seq_parameter_set const*, int, int, int, int, short*, int, unsigned char const*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/motion.cc:254
    #3 0x7ff9ff8262ab in generate_inter_prediction_samples(base_context*, slice_segment_header const*, de265_image*, int, int, int, int, int, int, int, PBMotion const*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/motion.cc:388
    #4 0x7ff9ff828626 in decode_prediction_unit(base_context*, slice_segment_header const*, de265_image*, PBMotionCoding const&, int, int, int, int, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/motion.cc:2107
    #5 0x7ff9ff89c8aa in read_coding_unit(thread_context*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:4314
    #6 0x7ff9ff8a48f2 in read_coding_quadtree(thread_context*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:4652
    #7 0x7ff9ff8a4e43 in read_coding_quadtree(thread_context*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:4638
    #8 0x7ff9ff8a4ace in read_coding_quadtree(thread_context*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:4645
    #9 0x7ff9ff8a4db9 in read_coding_quadtree(thread_context*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:4641
    #10 0x7ff9ff8a6564 in decode_substream(thread_context*, bool, bool) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:4741
    #11 0x7ff9ff8a8ddb in read_slice_segment_data(thread_context*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/slice.cc:5054
    #12 0x7ff9ff78dd75 in decoder_context::decode_slice_unit_sequential(image_unit*, slice_unit*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/decctx.cc:843
    #13 0x7ff9ff790c0f in decoder_context::decode_slice_unit_parallel(image_unit*, slice_unit*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/decctx.cc:945
    #14 0x7ff9ff791715 in decoder_context::decode_some(bool*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/decctx.cc:730
    #15 0x7ff9ff7949bb in decoder_context::read_slice_NAL(bitreader&, NAL_unit*, nal_header&) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/decctx.cc:688
    #16 0x7ff9ff795839 in decoder_context::decode_NAL(NAL_unit*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/decctx.cc:1230
    #17 0x7ff9ff796e1e in decoder_context::decode(int*) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/decctx.cc:1318
    #18 0x5573510028fd in main /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/dec265/dec265.cc:764
    #19 0x7ff9ff2e50b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
    #20 0x55735100576d in _start (/home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/out/dec265-afl+++0xa76d)

Address 0x7ffeacbd65e3 is located in stack of thread T0 at offset 9315 in frame
    #0 0x7ff9ff82e67f in void mc_chroma<unsigned char>(base_context const*, seq_parameter_set const*, int, int, int, int, short*, int, unsigned char const*, int, int, int, int) /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/motion.cc:174

  This frame has 2 object(s):
    [32, 9120) 'mcbuffer' (line 200)
    [9392, 14752) 'padbuf' (line 222) <== Memory access at offset 9315 underflows this variable
HINT: this may be a false positive if your program uses some custom stack unwind mechanism, swapcontext or vfork
      (longjmp and C++ exceptions *are* supported)
SUMMARY: AddressSanitizer: stack-buffer-overflow /home/dh/sda3/AFLplusplus/libde265-master/libde265-master-afl++/libde265/fallback-motion.cc:352 in void put_epel_hv_fallback<unsigned short>(short*, long, unsigned short const*, long, int, int, int, int, short*, int)
Shadow bytes around the buggy address:
  0x100055972c60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972c70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972c90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972ca0: 00 00 00 00 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2
=>0x100055972cb0: f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2[f2]f2 f2 f2
  0x100055972cc0: f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 00 00 00
  0x100055972cd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972ce0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972cf0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100055972d00: 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
==1262407==ABORTING


```











--- end body ---
