diff options
| author | Andreas Rheinhardt <andreas.rheinhardt@outlook.com> | 2021-04-05 02:05:58 +0200 |
|---|---|---|
| committer | Andreas Rheinhardt <andreas.rheinhardt@outlook.com> | 2021-04-08 01:17:24 +0200 |
| commit | 9abda1365c5e2d827eb673b6d98245163c868bf1 (patch) | |
| tree | e0c3436b48ef988b37fd0a861fdba4790ad88cb9 /libavcodec/rv34.c | |
| parent | 8ffd3ef9d94f33b411348c594a49d994b55c9550 (diff) | |
| download | ffmpeg-9abda1365c5e2d827eb673b6d98245163c868bf1.tar.gz | |
avcodec/rv34, mpegvideo: Fix segfault upon frame size change error
The RealVideo 3.0 and 4.0 decoders call ff_mpv_common_init() only during
their init function and not during decode_frame(); when the size of the
frame changes, they call ff_mpv_common_frame_size_change(). Yet upon
error, said function calls ff_mpv_common_end() which frees the whole
MpegEncContext and not only those parts that
ff_mpv_common_frame_size_change() reinits. As a result, the context will
never be usable again; worse, because decode_frame() contains no check
for whether the context is initialized or not, it is presumed that it is
initialized, leading to segfaults. Basically the same happens if
rv34_decoder_realloc() fails.
This commit fixes this by only resetting the parts that
ff_mpv_common_frame_size_change() changes upon error and by actually
checking whether the context is in need of reinitialization in
ff_rv34_decode_frame().
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Diffstat (limited to 'libavcodec/rv34.c')
| -rw-r--r-- | libavcodec/rv34.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/libavcodec/rv34.c b/libavcodec/rv34.c index 7e5bfe0e22..99e580a09a 100644 --- a/libavcodec/rv34.c +++ b/libavcodec/rv34.c @@ -1383,6 +1383,7 @@ static int rv34_decoder_alloc(RV34DecContext *r) if (!(r->cbp_chroma && r->cbp_luma && r->deblock_coefs && r->intra_types_hist && r->mb_type)) { + r->s.context_reinit = 1; rv34_decoder_free(r); return AVERROR(ENOMEM); } @@ -1530,7 +1531,7 @@ int ff_rv34_decode_update_thread_context(AVCodecContext *dst, const AVCodecConte if (dst == src || !s1->context_initialized) return 0; - if (s->height != s1->height || s->width != s1->width) { + if (s->height != s1->height || s->width != s1->width || s->context_reinit) { s->height = s1->height; s->width = s1->width; if ((err = ff_mpv_common_frame_size_change(s)) < 0) @@ -1667,11 +1668,12 @@ int ff_rv34_decode_frame(AVCodecContext *avctx, if (s->mb_num_left > 0 && s->current_picture_ptr) { av_log(avctx, AV_LOG_ERROR, "New frame but still %d MB left.\n", s->mb_num_left); - ff_er_frame_end(&s->er); + if (!s->context_reinit) + ff_er_frame_end(&s->er); ff_mpv_frame_end(s); } - if (s->width != si.width || s->height != si.height) { + if (s->width != si.width || s->height != si.height || s->context_reinit) { int err; av_log(s->avctx, AV_LOG_WARNING, "Changing dimensions to %dx%d\n", @@ -1689,7 +1691,6 @@ int ff_rv34_decode_frame(AVCodecContext *avctx, err = ff_set_dimensions(s->avctx, s->width, s->height); if (err < 0) return err; - if ((err = ff_mpv_common_frame_size_change(s)) < 0) return err; if ((err = rv34_decoder_realloc(r)) < 0) @@ -1744,6 +1745,10 @@ int ff_rv34_decode_frame(AVCodecContext *avctx, } s->mb_x = s->mb_y = 0; ff_thread_finish_setup(s->avctx); + } else if (s->context_reinit) { + av_log(s->avctx, AV_LOG_ERROR, "Decoder needs full frames to " + "reinitialize (start MB is %d).\n", si.start); + return AVERROR_INVALIDDATA; } else if (HAVE_THREADS && (s->avctx->active_thread_type & FF_THREAD_FRAME)) { av_log(s->avctx, AV_LOG_ERROR, "Decoder needs full frames in frame " |