[FFmpeg-devel] [PATCH 09/12] avformat/mxfdec: add support for clip wrapped essences

[Michael Niedermayer]

On Tue, Jun 12, 2018 at 11:59:26PM +0200, Marton Balint wrote:
> 
> 
> On Tue, 12 Jun 2018, Michael Niedermayer wrote:
> 
> >On Tue, Jun 12, 2018 at 10:47:24AM +0200, Marton Balint wrote:
> >>
> >>
> >>On Tue, 12 Jun 2018, Michael Niedermayer wrote:
> >>
> >>>On Sun, Jun 10, 2018 at 12:36:47PM +0200, Marton Balint wrote:
> >>>>Also use common code with opAtom.
> >>>>
> >>>>Fixes ticket #2776.
> >>>>Partially fixes ticket #5671.
> >>>>Fixes ticket #5866.
> >>>>
> >>>>Signed-off-by: Marton Balint <cus at passwd.hu>
> >>>>---
> >>>>libavformat/mxfdec.c | 281 ++++++++++++++++++++++++---------------------------
> >>>>1 file changed, 130 insertions(+), 151 deletions(-)
> >>>
> >>>causes a segfault:
> >>>
> >>>==23735== Invalid read of size 8
> >>>==23735==    at 0x75A627: mxf_set_pts (mxfdec.c:3277)
> >>>==23735==    by 0x75ACAD: mxf_read_packet_old (mxfdec.c:3396)
> >>>==23735==    by 0x7E099D: ff_read_packet (utils.c:856)
> >>>==23735==    by 0x7E39FF: read_frame_internal (utils.c:1581)
> >>>==23735==    by 0x7EB82B: avformat_find_stream_info (utils.c:3773)
> >>>==23735==    by 0x415534: open_input_file (ffmpeg_opt.c:1091)
> >>>==23735==    by 0x41EB11: open_files (ffmpeg_opt.c:3206)
> >>>==23735==    by 0x41ECA3: ffmpeg_parse_options (ffmpeg_opt.c:3246)
> >>>==23735==    by 0x43D1A3: main (ffmpeg.c:4832)
> >>>==23735==  Address 0x0 is not stack'd, malloc'd or (recently) free'd
> >>>==23735==
> >>>==23735==
> >>>==23735== Process terminating with default action of signal 11 (SIGSEGV)
> >>>==23735==  Access not within mapped region at address 0x0
> >>>==23735==    at 0x75A627: mxf_set_pts (mxfdec.c:3277)
> >>>==23735==    by 0x75ACAD: mxf_read_packet_old (mxfdec.c:3396)
> >>>==23735==    by 0x7E099D: ff_read_packet (utils.c:856)
> >>>==23735==    by 0x7E39FF: read_frame_internal (utils.c:1581)
> >>>==23735==    by 0x7EB82B: avformat_find_stream_info (utils.c:3773)
> >>>==23735==    by 0x415534: open_input_file (ffmpeg_opt.c:1091)
> >>>==23735==    by 0x41EB11: open_files (ffmpeg_opt.c:3206)
> >>>==23735==    by 0x41ECA3: ffmpeg_parse_options (ffmpeg_opt.c:3246)
> >>>==23735==    by 0x43D1A3: main (ffmpeg.c:4832)
> >>>==23735==  If you believe this happened as a result of a stack
> >>>==23735==  overflow in your program's main thread (unlikely but
> >>>==23735==  possible), you can try to increase the size of the
> >>>==23735==  main thread stack using the --main-stacksize= flag.
> >>>==23735==  The main thread stack size used in this run was 8388608.
> >>
> >>I don't see this. What is your command line?
> >
> >testcase sent privatly
> 
> index_table->nb_ptses was negative, but that did not cause problems before
> the patch, because the comparison to nb_ptses was signed, after the patch it
> became unsigned.
> 
> It is better to explicitly disallow a negative nb_ptses, please apply the
> attached patch before this one, you should be good.

confirmed, seems to fix it

thanks

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

You can kill me, but you cannot change the truth.
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