[FFmpeg-cvslog] vp3: fix oob read for negative tokens and memleaks on error.
Ronald S. Bultje
git at videolan.org
Mon Jan 9 00:22:25 CET 2012
ffmpeg | branch: release/0.7 | Ronald S. Bultje <rsbultje at gmail.com> | Fri Oct 28 23:50:04 2011 -0700| [c624935554332f8921a15265b8720f0c7b3c8cc2] | committer: Reinhard Tartler
vp3: fix oob read for negative tokens and memleaks on error.
(cherry picked from commit 8370e426e42f2e4b9d14a1fb8107ecfe5163ce7f)
Fixes: #189
Chromium-Bug: 101172,100465
CVE-2011-3892
Signed-off-by: Reinhard Tartler <siretart at tauware.de>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c624935554332f8921a15265b8720f0c7b3c8cc2
---
libavcodec/vp3.c | 59 +++++++++++++++++++++++++++++++++++++++++------------
1 files changed, 45 insertions(+), 14 deletions(-)
diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c
index 2b47e93..69e3d33 100644
--- a/libavcodec/vp3.c
+++ b/libavcodec/vp3.c
@@ -45,6 +45,7 @@
#define FRAGMENT_PIXELS 8
static av_cold int vp3_decode_end(AVCodecContext *avctx);
+static void vp3_decode_flush(AVCodecContext *avctx);
//FIXME split things out into their own arrays
typedef struct Vp3Fragment {
@@ -890,7 +891,7 @@ static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
/* decode a VLC into a token */
token = get_vlc2(gb, vlc_table, 11, 3);
/* use the token to get a zero run, a coefficient, and an eob run */
- if (token <= 6) {
+ if ((unsigned) token <= 6U) {
eob_run = eob_run_base[token];
if (eob_run_get_bits[token])
eob_run += get_bits(gb, eob_run_get_bits[token]);
@@ -908,7 +909,7 @@ static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
coeff_i += eob_run;
eob_run = 0;
}
- } else {
+ } else if (token >= 0) {
bits_to_get = coeff_get_bits[token];
if (bits_to_get)
bits_to_get = get_bits(gb, bits_to_get);
@@ -942,6 +943,10 @@ static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
for (i = coeff_index+1; i <= coeff_index+zero_run; i++)
s->num_coded_frags[plane][i]--;
coeff_i++;
+ } else {
+ av_log(s->avctx, AV_LOG_ERROR,
+ "Invalid token %d\n", token);
+ return -1;
}
}
@@ -991,6 +996,8 @@ static int unpack_dct_coeffs(Vp3DecodeContext *s, GetBitContext *gb)
/* unpack the Y plane DC coefficients */
residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_y_table], 0,
0, residual_eob_run);
+ if (residual_eob_run < 0)
+ return residual_eob_run;
/* reverse prediction of the Y-plane DC coefficients */
reverse_dc_prediction(s, 0, s->fragment_width[0], s->fragment_height[0]);
@@ -998,8 +1005,12 @@ static int unpack_dct_coeffs(Vp3DecodeContext *s, GetBitContext *gb)
/* unpack the C plane DC coefficients */
residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_c_table], 0,
1, residual_eob_run);
+ if (residual_eob_run < 0)
+ return residual_eob_run;
residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_c_table], 0,
2, residual_eob_run);
+ if (residual_eob_run < 0)
+ return residual_eob_run;
/* reverse prediction of the C-plane DC coefficients */
if (!(s->avctx->flags & CODEC_FLAG_GRAY))
@@ -1036,11 +1047,17 @@ static int unpack_dct_coeffs(Vp3DecodeContext *s, GetBitContext *gb)
for (i = 1; i <= 63; i++) {
residual_eob_run = unpack_vlcs(s, gb, y_tables[i], i,
0, residual_eob_run);
+ if (residual_eob_run < 0)
+ return residual_eob_run;
residual_eob_run = unpack_vlcs(s, gb, c_tables[i], i,
1, residual_eob_run);
+ if (residual_eob_run < 0)
+ return residual_eob_run;
residual_eob_run = unpack_vlcs(s, gb, c_tables[i], i,
2, residual_eob_run);
+ if (residual_eob_run < 0)
+ return residual_eob_run;
}
return 0;
@@ -1789,10 +1806,15 @@ static int vp3_update_thread_context(AVCodecContext *dst, const AVCodecContext *
Vp3DecodeContext *s = dst->priv_data, *s1 = src->priv_data;
int qps_changed = 0, i, err;
+#define copy_fields(to, from, start_field, end_field) memcpy(&to->start_field, &from->start_field, (char*)&to->end_field - (char*)&to->start_field)
+
if (!s1->current_frame.data[0]
||s->width != s1->width
- ||s->height!= s1->height)
+ ||s->height!= s1->height) {
+ if (s != s1)
+ copy_fields(s, s1, golden_frame, current_frame);
return -1;
+ }
if (s != s1) {
// init tables if the first frame hasn't been decoded
@@ -1808,8 +1830,6 @@ static int vp3_update_thread_context(AVCodecContext *dst, const AVCodecContext *
memcpy(s->motion_val[1], s1->motion_val[1], c_fragment_count * sizeof(*s->motion_val[1]));
}
-#define copy_fields(to, from, start_field, end_field) memcpy(&to->start_field, &from->start_field, (char*)&to->end_field - (char*)&to->start_field)
-
// copy previous frame data
copy_fields(s, s1, golden_frame, dsp);
@@ -1999,9 +2019,6 @@ static av_cold int vp3_decode_end(AVCodecContext *avctx)
Vp3DecodeContext *s = avctx->priv_data;
int i;
- if (avctx->is_copy && !s->current_frame.data[0])
- return 0;
-
av_free(s->superblock_coding);
av_free(s->all_fragments);
av_free(s->coded_fragment_list[0]);
@@ -2028,12 +2045,7 @@ static av_cold int vp3_decode_end(AVCodecContext *avctx)
free_vlc(&s->motion_vector_vlc);
/* release all frames */
- if (s->golden_frame.data[0])
- ff_thread_release_buffer(avctx, &s->golden_frame);
- if (s->last_frame.data[0] && s->last_frame.type != FF_BUFFER_TYPE_COPY)
- ff_thread_release_buffer(avctx, &s->last_frame);
- /* no need to release the current_frame since it will always be pointing
- * to the same frame as either the golden or last frame */
+ vp3_decode_flush(avctx);
return 0;
}
@@ -2353,6 +2365,23 @@ static void vp3_decode_flush(AVCodecContext *avctx)
ff_thread_release_buffer(avctx, &s->current_frame);
}
+static int vp3_init_thread_copy(AVCodecContext *avctx)
+{
+ Vp3DecodeContext *s = avctx->priv_data;
+
+ s->superblock_coding = NULL;
+ s->all_fragments = NULL;
+ s->coded_fragment_list[0] = NULL;
+ s->dct_tokens_base = NULL;
+ s->superblock_fragments = NULL;
+ s->macroblock_coding = NULL;
+ s->motion_val[0] = NULL;
+ s->motion_val[1] = NULL;
+ s->edge_emu_buffer = NULL;
+
+ return 0;
+}
+
AVCodec ff_theora_decoder = {
"theora",
AVMEDIA_TYPE_VIDEO,
@@ -2366,6 +2395,7 @@ AVCodec ff_theora_decoder = {
NULL,
.flush = vp3_decode_flush,
.long_name = NULL_IF_CONFIG_SMALL("Theora"),
+ .init_thread_copy = ONLY_IF_THREADS_ENABLED(vp3_init_thread_copy),
.update_thread_context = ONLY_IF_THREADS_ENABLED(vp3_update_thread_context)
};
#endif
@@ -2383,5 +2413,6 @@ AVCodec ff_vp3_decoder = {
NULL,
.flush = vp3_decode_flush,
.long_name = NULL_IF_CONFIG_SMALL("On2 VP3"),
+ .init_thread_copy = ONLY_IF_THREADS_ENABLED(vp3_init_thread_copy),
.update_thread_context = ONLY_IF_THREADS_ENABLED(vp3_update_thread_context)
};
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