#8274: heap-buffer-overflow at libavfilter/vf_avgblur.c:172
-------------------------------------+-------------------------------------
Reporter: Suhwan | Type: defect
Status: new | Priority: important
Component: | Version: git-
undetermined | master
Keywords: asan | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Summary of the bug:
There is a heap-buffer-overflow at libavfilter/vf_avgblur.c:172 in
filter_vertically_8
I compiled ffmpeg with "--toolchain=clang-asan" to check the memory
corruption and attached log file.
How to reproduce:
{{{
% ffmpeg_g -y -i $PoC -filter_complex avgblur -target dv50 -loglevel 99
tmp.acm
ffmpeg version N-95382-g62f4722582 Copyright (c) 2000-2019 the FFmpeg
developers
built with clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
configuration: --cc=clang --cxx=clang++ --ld=clang --enable-debug
--toolchain=clang-asan
}}}
Here's ASAN log
{{{
=================================================================
==6091==ERROR: AddressSanitizer: heap-buffer-overflow on address
0x609000006c50 at pc 0x0000009a519a bp 0x7ffff1725c40 sp 0x7ffff1725c38
READ of size 4 at 0x609000006c50 thread T1
#0 0x9a5199 in filter_vertically_8
ffmpeg/libavfilter/vf_avgblur.c:172:1
#1 0x942909 in worker_func ffmpeg/libavfilter/pthread.c:50:15
#2 0x86863a2 in run_jobs ffmpeg/libavutil/slicethread.c:61:9
#3 0x8683d0d in thread_worker ffmpeg/libavutil/slicethread.c:85:13
#4 0x4eb9de in __asan::AsanThread::ThreadStart(unsigned long,
__sanitizer::atomic_uintptr_t*) (ffmpeg_asan+0x4eb9de)
#5 0x7ffff668e6da in start_thread (/lib/x86_64-linux-
gnu/libpthread.so.0+0x76da)
#6 0x7ffff5d9388e in clone /build/glibc-
OTsEL5/glibc-2.27/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:95
0x609000006c50 is located 0 bytes to the right of 16-byte region
[0x609000006c40,0x609000006c50)
allocated by thread T0 here:
#0 0x4de9e8 in posix_memalign (ffmpeg_asan+0x4de9e8)
#1 0x8592f19 in av_malloc ffmpeg/libavutil/mem.c:87:9
#2 0x8592f19 in av_malloc_array ffmpeg/libavutil/mem.c:188
#3 0x9a0bf3 in config_input ffmpeg/libavfilter/vf_avgblur.c:188:17
Thread T1 created by T0 here:
#0 0x436f80 in pthread_create (ffmpeg_asan+0x436f80)
#1 0x8682ef9 in avpriv_slicethread_create
ffmpeg/libavutil/slicethread.c:147:19
SUMMARY: AddressSanitizer: heap-buffer-overflow
ffmpeg/libavfilter/vf_avgblur.c:172:1 in filter_vertically_8
Shadow bytes around the buggy address:
0x0c127fff8d30: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c127fff8d40: 00 fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c127fff8d50: 00 00 00 fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c127fff8d60: 00 fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c127fff8d70: 00 00 00 fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0c127fff8d80: fa fa fa fa fa fa fa fa 00 00[fa]fa fa fa fa fa
0x0c127fff8d90: fa fa fa fa fa fa fa fa fd fa fa fa fa fa fa fa
0x0c127fff8da0: fa fa fa fa fa fa fa fa fd fa fa fa fa fa fa fa
0x0c127fff8db0: fa fa fa fa fa fa fa fa fd fa fa fa fa fa fa fa
0x0c127fff8dc0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c127fff8dd0: 00 00 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
==6091==ABORTING
}}}
Please confirm.
Thanks
--
Ticket URL: <https://trac.ffmpeg.org/ticket/8274>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker
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