[FFmpeg-cvslog] avcodec: Ignoring errors is only possible before the input end

[Michael Niedermayer]

ffmpeg | branch: release/3.4 | Michael Niedermayer <michael at niedermayer.cc> | Sat Jun  3 21:44:37 2023 +0200| [7167952f0ee6f38a3d145488048413810358409c] | committer: Michael Niedermayer

avcodec: Ignoring errors is only possible before the input end

Fixes: out of array read
Fixes: Ticket 10308

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit fead656a7bf523d448fe8bd39c1f2ea36be98fb9)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7167952f0ee6f38a3d145488048413810358409c
---

 libavcodec/h263dec.c       | 2 +-
 libavcodec/mpeg4videodec.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/libavcodec/h263dec.c b/libavcodec/h263dec.c
index b13892ddbb..b2939abd16 100644
--- a/libavcodec/h263dec.c
+++ b/libavcodec/h263dec.c
@@ -289,7 +289,7 @@ static int decode_slice(MpegEncContext *s)
                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
                                 s->mb_x, s->mb_y, ER_MB_ERROR & part_mask);
 
-                if (s->avctx->err_recognition & AV_EF_IGNORE_ERR)
+                if ((s->avctx->err_recognition & AV_EF_IGNORE_ERR) && get_bits_left(&s->gb) > 0)
                     continue;
                 return AVERROR_INVALIDDATA;
             }
diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c
index 11cf530cdd..81a73a466f 100644
--- a/libavcodec/mpeg4videodec.c
+++ b/libavcodec/mpeg4videodec.c
@@ -1128,7 +1128,7 @@ static inline int mpeg4_decode_block(Mpeg4DecContext *ctx, int16_t *block,
                                 if (SHOW_UBITS(re, &s->gb, 1) == 0) {
                                     av_log(s->avctx, AV_LOG_ERROR,
                                            "1. marker bit missing in 3. esc\n");
-                                    if (!(s->avctx->err_recognition & AV_EF_IGNORE_ERR))
+                                    if (!(s->avctx->err_recognition & AV_EF_IGNORE_ERR) || get_bits_left(&s->gb) <= 0)
                                         return -1;
                                 }
                                 SKIP_CACHE(re, &s->gb, 1);
@@ -1139,7 +1139,7 @@ static inline int mpeg4_decode_block(Mpeg4DecContext *ctx, int16_t *block,
                                 if (SHOW_UBITS(re, &s->gb, 1) == 0) {
                                     av_log(s->avctx, AV_LOG_ERROR,
                                            "2. marker bit missing in 3. esc\n");
-                                    if (!(s->avctx->err_recognition & AV_EF_IGNORE_ERR))
+                                    if (!(s->avctx->err_recognition & AV_EF_IGNORE_ERR) || get_bits_left(&s->gb) <= 0)
                                         return -1;
                                 }