1 files changed, 107 insertions, 44 deletions

diff --git a/libavcodec/4xm.c b/libavcodec/4xm.c
index fa5256c..406ca72 100644
--- a/libavcodec/4xm.c
+++ b/libavcodec/4xm.c
@@ -2,20 +2,20 @@
  * 4XM codec
  * Copyright (c) 2003 Michael Niedermayer
  *
- * This file is part of Libav.
+ * This file is part of FFmpeg.
  *
- * Libav is free software; you can redistribute it and/or
+ * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
- * Libav is distributed in the hope that it will be useful,
+ * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with Libav; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
@@ -31,8 +31,7 @@
 #include "get_bits.h"
 #include "internal.h"
 
-//#undef NDEBUG
-//#include <assert.h>
+#include "libavutil/avassert.h"
 
 #define BLOCK_TYPE_VLC_BITS 5
 #define ACDC_VLC_BITS 9
@@ -285,7 +284,7 @@ static void init_mv(FourXContext *f)
     }
 #endif
 
-static inline void mcdc(uint16_t *dst, uint16_t *src, int log2w,
+static inline void mcdc(uint16_t *dst, const uint16_t *src, int log2w,
                         int h, int stride, int scale, unsigned dc)
 {
     int i;
@@ -329,7 +328,7 @@ static inline void mcdc(uint16_t *dst, uint16_t *src, int log2w,
         }
         break;
     default:
-        assert(0);
+        av_assert2(0);
     }
 }
 
@@ -344,10 +343,14 @@ static void decode_p_block(FourXContext *f, uint16_t *dst, uint16_t *src,
     uint16_t *start = (uint16_t *)f->last_picture->data[0];
     uint16_t *end   = start + stride * (f->avctx->height - h + 1) - (1 << log2w);
 
-    assert(code >= 0 && code <= 6);
+    av_assert2(code >= 0 && code <= 6);
 
     if (code == 0) {
-        src += f->mv[bytestream2_get_byte(&f->g)];
+        if (bytestream2_get_bytes_left(&f->g) < 1) {
+            av_log(f->avctx, AV_LOG_ERROR, "bytestream overread\n");
+            return;
+        }
+        src += f->mv[bytestream2_get_byteu(&f->g)];
         if (start > src || src > end) {
             av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
             return;
@@ -366,21 +369,37 @@ static void decode_p_block(FourXContext *f, uint16_t *dst, uint16_t *src,
     } else if (code == 3 && f->version < 2) {
         mcdc(dst, src, log2w, h, stride, 1, 0);
     } else if (code == 4) {
-        src += f->mv[bytestream2_get_byte(&f->g)];
+        if (bytestream2_get_bytes_left(&f->g) < 1) {
+            av_log(f->avctx, AV_LOG_ERROR, "bytestream overread\n");
+            return;
+        }
+        src += f->mv[bytestream2_get_byteu(&f->g)];
         if (start > src || src > end) {
             av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
             return;
         }
-        mcdc(dst, src, log2w, h, stride, 1, bytestream2_get_le16(&f->g2));
+        if (bytestream2_get_bytes_left(&f->g2) < 2){
+            av_log(f->avctx, AV_LOG_ERROR, "wordstream overread\n");
+            return;
+        }
+        mcdc(dst, src, log2w, h, stride, 1, bytestream2_get_le16u(&f->g2));
     } else if (code == 5) {
-        mcdc(dst, src, log2w, h, stride, 0, bytestream2_get_le16(&f->g2));
+        if (bytestream2_get_bytes_left(&f->g2) < 2) {
+            av_log(f->avctx, AV_LOG_ERROR, "wordstream overread\n");
+            return;
+        }
+        mcdc(dst, src, log2w, h, stride, 0, bytestream2_get_le16u(&f->g2));
     } else if (code == 6) {
+        if (bytestream2_get_bytes_left(&f->g2) < 4) {
+            av_log(f->avctx, AV_LOG_ERROR, "wordstream overread\n");
+            return;
+        }
         if (log2w) {
-            dst[0]      = bytestream2_get_le16(&f->g2);
-            dst[1]      = bytestream2_get_le16(&f->g2);
+            dst[0]      = bytestream2_get_le16u(&f->g2);
+            dst[1]      = bytestream2_get_le16u(&f->g2);
         } else {
-            dst[0]      = bytestream2_get_le16(&f->g2);
-            dst[stride] = bytestream2_get_le16(&f->g2);
+            dst[0]      = bytestream2_get_le16u(&f->g2);
+            dst[stride] = bytestream2_get_le16u(&f->g2);
         }
     }
 }
@@ -398,6 +417,8 @@ static int decode_p_frame(FourXContext *f, const uint8_t *buf, int length)
 
     if (f->version > 1) {
         extra           = 20;
+        if (length < extra)
+            return -1;
         bitstream_size  = AV_RL32(buf + 8);
         wordstream_size = AV_RL32(buf + 12);
         bytestream_size = AV_RL32(buf + 16);
@@ -408,13 +429,12 @@ static int decode_p_frame(FourXContext *f, const uint8_t *buf, int length)
         bytestream_size = FFMAX(length - bitstream_size - wordstream_size, 0);
     }
 
-    if (bitstream_size + bytestream_size + wordstream_size + extra != length
-        || bitstream_size  > (1 << 26)
-        || bytestream_size > (1 << 26)
-        || wordstream_size > (1 << 26)) {
-        av_log(f->avctx, AV_LOG_ERROR, "lengths %d %d %d %d\n",
-               bitstream_size, bytestream_size, wordstream_size,
-               bitstream_size + bytestream_size + wordstream_size - length);
+    if (bitstream_size > length || bitstream_size >= INT_MAX/8 ||
+        bytestream_size > length - bitstream_size ||
+        wordstream_size > length - bytestream_size - bitstream_size ||
+        extra > length - bytestream_size - bitstream_size - wordstream_size) {
+        av_log(f->avctx, AV_LOG_ERROR, "lengths %d %d %d %d\n", bitstream_size, bytestream_size, wordstream_size,
+        bitstream_size+ bytestream_size+ wordstream_size - length);
         return AVERROR_INVALIDDATA;
     }
 
@@ -455,6 +475,11 @@ static int decode_i_block(FourXContext *f, int16_t *block)
 {
     int code, i, j, level, val;
 
+    if (get_bits_left(&f->gb) < 2){
+        av_log(f->avctx, AV_LOG_ERROR, "%d bits left before decode_i_block()\n", get_bits_left(&f->gb));
+        return -1;
+    }
+
     /* DC coef */
     val = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
     if (val >> 4)
@@ -555,7 +580,7 @@ static int decode_i_mb(FourXContext *f)
 }
 
 static const uint8_t *read_huffman_tables(FourXContext *f,
-                                          const uint8_t * const buf)
+                                          const uint8_t * const buf, int buf_size)
 {
     int frequency[512] = { 0 };
     uint8_t flag[512];
@@ -564,6 +589,7 @@ static const uint8_t *read_huffman_tables(FourXContext *f,
     int bits_tab[257];
     int start, end;
     const uint8_t *ptr = buf;
+    const uint8_t *ptr_end = buf + buf_size;
     int j;
 
     memset(up, -1, sizeof(up));
@@ -573,6 +599,10 @@ static const uint8_t *read_huffman_tables(FourXContext *f,
     for (;;) {
         int i;
 
+        if (ptr_end - ptr < FFMAX(end - start + 1, 0) + 1) {
+            av_log(f->avctx, AV_LOG_ERROR, "invalid data in read_huffman_tables\n");
+            return NULL;
+        }
         for (i = start; i <= end; i++)
             frequency[i] = *ptr++;
         start = *ptr++;
@@ -586,6 +616,11 @@ static const uint8_t *read_huffman_tables(FourXContext *f,
     while ((ptr - buf) & 3)
         ptr++; // 4byte align
 
+    if (ptr > ptr_end) {
+        av_log(f->avctx, AV_LOG_ERROR, "ptr overflow in read_huffman_tables\n");
+        return NULL;
+    }
+
     for (j = 257; j < 512; j++) {
         int min_freq[2] = { 256 * 256, 256 * 256 };
         int smallest[2] = { 0, 0 };
@@ -655,6 +690,7 @@ static int decode_i2_frame(FourXContext *f, const uint8_t *buf, int length)
     const int mbs    = (FFALIGN(width, 16) >> 4) * (FFALIGN(height, 16) >> 4);
     uint16_t *dst    = (uint16_t*)f->current_picture->data[0];
     const int stride =            f->current_picture->linesize[0]>>1;
+    const uint8_t *buf_end = buf + length;
     GetByteContext g3;
 
     if (length < mbs * 8) {
@@ -666,6 +702,8 @@ static int decode_i2_frame(FourXContext *f, const uint8_t *buf, int length)
     for (y = 0; y < height; y += 16) {
         for (x = 0; x < width; x += 16) {
             unsigned int color[4] = { 0 }, bits;
+            if (buf_end - buf < 8)
+                return -1;
             // warning following is purely guessed ...
             color[0] = bytestream2_get_le16u(&g3);
             color[1] = bytestream2_get_le16u(&g3);
@@ -699,16 +737,14 @@ static int decode_i_frame(FourXContext *f, const uint8_t *buf, int length)
     const int width  = f->avctx->width;
     const int height = f->avctx->height;
     const unsigned int bitstream_size = AV_RL32(buf);
-    int token_count av_unused;
     unsigned int prestream_size;
     const uint8_t *prestream;
 
-    if (length < bitstream_size + 12) {
+    if (bitstream_size > (1<<26) || length < bitstream_size + 12) {
         av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");
         return AVERROR_INVALIDDATA;
     }
 
-    token_count    =     AV_RL32(buf + bitstream_size + 8);
     prestream_size = 4 * AV_RL32(buf + bitstream_size + 4);
     prestream      =             buf + bitstream_size + 12;
 
@@ -720,7 +756,11 @@ static int decode_i_frame(FourXContext *f, const uint8_t *buf, int length)
         return AVERROR_INVALIDDATA;
     }
 
-    prestream = read_huffman_tables(f, prestream);
+    prestream = read_huffman_tables(f, prestream, buf + length - prestream);
+    if (!prestream)
+        return -1;
+
+    av_assert0(prestream <= buf + length);
 
     init_get_bits(&f->gb, buf + 4, 8 * bitstream_size);
 
@@ -763,6 +803,8 @@ static int decode_frame(AVCodecContext *avctx, void *data,
     AVFrame *p;
     int i, frame_4cc, frame_size, ret;
 
+    if (buf_size < 12)
+        return AVERROR_INVALIDDATA;
     frame_4cc = AV_RL32(buf);
     if (buf_size != AV_RL32(buf + 4) + 8 || buf_size < 20)
         av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d\n",
@@ -775,6 +817,16 @@ static int decode_frame(AVCodecContext *avctx, void *data,
         const int whole_size = AV_RL32(buf + 16);
         CFrameBuffer *cfrm;
 
+        if (data_size < 0 || whole_size < 0) {
+            av_log(f->avctx, AV_LOG_ERROR, "sizes invalid\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        if (f->version <= 1) {
+            av_log(f->avctx, AV_LOG_ERROR, "cfrm in version %d\n", f->version);
+            return AVERROR_INVALIDDATA;
+        }
+
         for (i = 0; i < CFRAME_BUFFER_COUNT; i++)
             if (f->cfrm[i].id && f->cfrm[i].id < avctx->frame_number)
                 av_log(f->avctx, AV_LOG_ERROR, "lost c frame %d\n",
@@ -793,11 +845,14 @@ static int decode_frame(AVCodecContext *avctx, void *data,
         }
         cfrm = &f->cfrm[i];
 
+        if (data_size > UINT_MAX -  cfrm->size - FF_INPUT_BUFFER_PADDING_SIZE)
+            return AVERROR_INVALIDDATA;
+
         cfrm->data = av_fast_realloc(cfrm->data, &cfrm->allocated_size,
                                      cfrm->size + data_size + FF_INPUT_BUFFER_PADDING_SIZE);
         // explicit check needed as memcpy below might not catch a NULL
         if (!cfrm->data) {
-            av_log(f->avctx, AV_LOG_ERROR, "realloc failure");
+            av_log(f->avctx, AV_LOG_ERROR, "realloc failure\n");
             return AVERROR(ENOMEM);
         }
 
@@ -829,36 +884,40 @@ static int decode_frame(AVCodecContext *avctx, void *data,
     // alternatively we would have to use our own buffer management
     avctx->flags |= CODEC_FLAG_EMU_EDGE;
 
-    if (p->data[0])
-        avctx->release_buffer(avctx, p);
-
-    p->reference = 1;
-    if ((ret = ff_get_buffer(avctx, p)) < 0) {
-        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+    p->reference= 3;
+    if ((ret = avctx->reget_buffer(avctx, p)) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
         return ret;
     }
 
     if (frame_4cc == AV_RL32("ifr2")) {
-        p->pict_type = AV_PICTURE_TYPE_I;
-        if ((ret = decode_i2_frame(f, buf - 4, frame_size + 4)) < 0)
+        p->pict_type= AV_PICTURE_TYPE_I;
+        if ((ret = decode_i2_frame(f, buf - 4, frame_size + 4)) < 0) {
+            av_log(f->avctx, AV_LOG_ERROR, "decode i2 frame failed\n");
             return ret;
+        }
     } else if (frame_4cc == AV_RL32("ifrm")) {
-        p->pict_type = AV_PICTURE_TYPE_I;
-        if ((ret = decode_i_frame(f, buf, frame_size)) < 0)
+        p->pict_type= AV_PICTURE_TYPE_I;
+        if ((ret = decode_i_frame(f, buf, frame_size)) < 0) {
+            av_log(f->avctx, AV_LOG_ERROR, "decode i frame failed\n");
             return ret;
+        }
     } else if (frame_4cc == AV_RL32("pfrm") || frame_4cc == AV_RL32("pfr2")) {
         if (!f->last_picture->data[0]) {
-            f->last_picture->reference = 1;
+            f->last_picture->reference = 3;
             if ((ret = ff_get_buffer(avctx, f->last_picture)) < 0) {
                 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
                 return ret;
             }
-            memset(f->last_picture->data[0], 0, avctx->height * FFABS(f->last_picture->linesize[0]));
+            for (i=0; i<avctx->height; i++)
+                memset(f->last_picture->data[0] + i*f->last_picture->linesize[0], 0, 2*avctx->width);
         }
 
         p->pict_type = AV_PICTURE_TYPE_P;
-        if ((ret = decode_p_frame(f, buf, frame_size)) < 0)
+        if ((ret = decode_p_frame(f, buf, frame_size)) < 0) {
+            av_log(f->avctx, AV_LOG_ERROR, "decode p frame failed\n");
             return ret;
+        }
     } else if (frame_4cc == AV_RL32("snd_")) {
         av_log(avctx, AV_LOG_ERROR, "ignoring snd_ chunk length:%d\n",
                buf_size);
@@ -883,7 +942,11 @@ static av_cold int decode_init(AVCodecContext *avctx)
 
     if (avctx->extradata_size != 4 || !avctx->extradata) {
         av_log(avctx, AV_LOG_ERROR, "extradata wrong or missing\n");
-        return 1;
+        return AVERROR_INVALIDDATA;
+    }
+    if((avctx->width % 16) || (avctx->height % 16)) {
+        av_log(avctx, AV_LOG_ERROR, "unsupported width/height\n");
+        return AVERROR_INVALIDDATA;
     }
 
     f->version = AV_RL32(avctx->extradata) >> 16;