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| author | Janne Grunau <janne-libav@jannau.net> | 2012-12-15 22:21:23 +0100 |
|---|---|---|
| committer | Janne Grunau <janne-libav@jannau.net> | 2012-12-18 11:01:14 +0100 |
| commit | 61c6eef5456f2bc8b1dc49a0a759c975551cea29 (patch) | |
| tree | 33bee5b20a90f39428dcf2eec256cc93323bca53 /libavcodec/h264.c | |
| parent | 26e4f0c70f781a16f4234c101ceceb640ec5ff31 (diff) | |
| download | ffmpeg-61c6eef5456f2bc8b1dc49a0a759c975551cea29.tar.gz | |
h264: prevent decoding of slice NALs in extradata
It is not posible to call get_buffer during frame-mt codec
initialization. Libavformat might pass huge amounts of data as
extradata after parsing broken files. The 'extradata' for the fuzzed
sample sample_varPAR_s5374_r001-02.avi is 2.8M large and contains
multiple slices.
Diffstat (limited to 'libavcodec/h264.c')
| -rw-r--r-- | libavcodec/h264.c | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/libavcodec/h264.c b/libavcodec/h264.c index 4146b6f052..f568858792 100644 --- a/libavcodec/h264.c +++ b/libavcodec/h264.c @@ -954,7 +954,8 @@ fail: return -1; // free_tables will clean up for us } -static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size); +static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size, + int parse_extradata); static av_cold void common_init(H264Context *h) { @@ -1001,7 +1002,7 @@ int ff_h264_decode_extradata(H264Context *h) nalsize = AV_RB16(p) + 2; if (p - avctx->extradata + nalsize > avctx->extradata_size) return -1; - if (decode_nal_units(h, p, nalsize) < 0) { + if (decode_nal_units(h, p, nalsize, 1) < 0) { av_log(avctx, AV_LOG_ERROR, "Decoding sps %d from avcC failed\n", i); return -1; @@ -1014,7 +1015,7 @@ int ff_h264_decode_extradata(H264Context *h) nalsize = AV_RB16(p) + 2; if (p - avctx->extradata + nalsize > avctx->extradata_size) return -1; - if (decode_nal_units(h, p, nalsize) < 0) { + if (decode_nal_units(h, p, nalsize, 1) < 0) { av_log(avctx, AV_LOG_ERROR, "Decoding pps %d from avcC failed\n", i); return -1; @@ -1025,7 +1026,7 @@ int ff_h264_decode_extradata(H264Context *h) h->nal_length_size = (avctx->extradata[4] & 0x03) + 1; } else { h->is_avc = 0; - if (decode_nal_units(h, avctx->extradata, avctx->extradata_size) < 0) + if (decode_nal_units(h, avctx->extradata, avctx->extradata_size, 1) < 0) return -1; } return 0; @@ -3708,7 +3709,8 @@ static int execute_decode_slices(H264Context *h, int context_count) return 0; } -static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size) +static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size, + int parse_extradata) { MpegEncContext *const s = &h->s; AVCodecContext *const avctx = s->avctx; @@ -3831,6 +3833,17 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size) continue; again: + /* Ignore every NAL unit type except PPS and SPS during extradata + * parsing. Decoding slices is not possible in codec init + * with frame-mt */ + if (parse_extradata && HAVE_THREADS && + (s->avctx->active_thread_type & FF_THREAD_FRAME) && + (hx->nal_unit_type != NAL_PPS && + hx->nal_unit_type != NAL_SPS)) { + av_log(avctx, AV_LOG_INFO, "Ignoring NAL unit %d during " + "extradata parsing\n", hx->nal_unit_type); + hx->nal_unit_type = NAL_FF_IGNORE; + } err = 0; switch (hx->nal_unit_type) { case NAL_IDR_SLICE: @@ -3953,6 +3966,8 @@ again: case NAL_SPS_EXT: case NAL_AUXILIARY_SLICE: break; + case NAL_FF_IGNORE: + break; default: av_log(avctx, AV_LOG_DEBUG, "Unknown NAL code: %d (%d bits)\n", hx->nal_unit_type, bit_length); @@ -4049,7 +4064,7 @@ out: return buf_index; } - buf_index = decode_nal_units(h, buf, buf_size); + buf_index = decode_nal_units(h, buf, buf_size, 0); if (buf_index < 0) return -1; |