Merge commit '85b8b169175a55fc862e01ecc96f649374bc14d2' into release/1.1

* commit '85b8b169175a55fc862e01ecc96f649374bc14d2':
  tiffdec: use bytestream2 to simplify overread/overwrite protection

Conflicts:
	libavcodec/tiff.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 37 insertions, 29 deletions

diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c
index 0824934025..7394655c8e 100644
--- a/libavcodec/tiff.c
+++ b/libavcodec/tiff.c
@@ -409,6 +409,7 @@ static void av_always_inline horizontal_fill(unsigned int bpp, uint8_t* dst,
 static int tiff_unpack_strip(TiffContext *s, uint8_t *dst, int stride,
                              const uint8_t *src, int size, int lines)
 {
+    PutByteContext pb;
     int c, line, pixels, code;
     const uint8_t *ssrc = src;
     int width = ((s->width * s->bpp) + 7) >> 3;
@@ -479,6 +480,18 @@ static int tiff_unpack_strip(TiffContext *s, uint8_t *dst, int stride,
             av_log(s->avctx, AV_LOG_ERROR, "Error initializing LZW decoder\n");
             return -1;
         }
+        for (line = 0; line < lines; line++) {
+            pixels = ff_lzw_decode(s->lzw, dst, width);
+            if (pixels < width) {
+                av_log(s->avctx, AV_LOG_ERROR, "Decoded only %i bytes of %i\n",
+                       pixels, width);
+                return AVERROR_INVALIDDATA;
+            }
+            if (s->bpp < 8 && s->avctx->pix_fmt == AV_PIX_FMT_PAL8)
+                horizontal_fill(s->bpp, dst, 1, dst, 0, width, 0);
+            dst += stride;
+        }
+        return 0;
     }
     if (s->compr == TIFF_CCITT_RLE || s->compr == TIFF_G3
         || s->compr == TIFF_G4) {
@@ -520,15 +533,24 @@ static int tiff_unpack_strip(TiffContext *s, uint8_t *dst, int stride,
         av_free(src2);
         return ret;
     }
+
+    bytestream2_init(&s->gb, src, size);
+    bytestream2_init_writer(&pb, dst, stride * lines);
+
     for (line = 0; line < lines; line++) {
         if (src - ssrc > size) {
             av_log(s->avctx, AV_LOG_ERROR, "Source data overread\n");
             return -1;
         }
+
+        if (bytestream2_get_bytes_left(&s->gb) == 0 || bytestream2_get_eof(&pb))
+            break;
+        bytestream2_seek_p(&pb, stride * line, SEEK_SET);
         switch (s->compr) {
         case TIFF_RAW:
             if (ssrc + size - src < width)
                 return AVERROR_INVALIDDATA;
+
             if (!s->fill_order) {
                 horizontal_fill(s->bpp * (s->avctx->pix_fmt == AV_PIX_FMT_PAL8),
                                 dst, 1, src, 0, width, 0);
@@ -572,16 +594,6 @@ static int tiff_unpack_strip(TiffContext *s, uint8_t *dst, int stride,
                 }
             }
             break;
-        case TIFF_LZW:
-            pixels = ff_lzw_decode(s->lzw, dst, width);
-            if (pixels < width) {
-                av_log(s->avctx, AV_LOG_ERROR, "Decoded only %i bytes of %i\n",
-                       pixels, width);
-                return -1;
-            }
-            if (s->bpp < 8 && s->avctx->pix_fmt == AV_PIX_FMT_PAL8)
-                horizontal_fill(s->bpp, dst, 1, dst, 0, width, 0);
-            break;
         }
         dst += stride;
     }
@@ -655,7 +667,8 @@ static int init_image(TiffContext *s)
 static int tiff_decode_tag(TiffContext *s)
 {
     unsigned tag, type, count, off, value = 0;
-    int i, j, k, pos, start;
+    int i, start;
+    int j, k, pos;
     int ret;
     uint32_t *pal;
     double *dp;
@@ -797,27 +810,17 @@ static int tiff_decode_tag(TiffContext *s)
         if (s->strips == 1)
             s->rps = s->height;
         s->sot = type;
-        if (s->strippos > bytestream2_size(&s->gb)) {
-            av_log(s->avctx, AV_LOG_ERROR,
-                   "Tag referencing position outside the image\n");
-            return -1;
-        }
         break;
     case TIFF_STRIP_SIZE:
         if (count == 1) {
             s->stripsizesoff = 0;
-            s->stripsize = value;
-            s->strips = 1;
+            s->stripsize     = value;
+            s->strips        = 1;
         } else {
             s->stripsizesoff = off;
         }
         s->strips = count;
         s->sstype = type;
-        if (s->stripsizesoff > bytestream2_size(&s->gb)) {
-            av_log(s->avctx, AV_LOG_ERROR,
-                   "Tag referencing position outside the image\n");
-            return -1;
-        }
         break;
     case TIFF_TILE_BYTE_COUNTS:
     case TIFF_TILE_LENGTH:
@@ -854,11 +857,13 @@ static int tiff_decode_tag(TiffContext *s)
         }
         s->fill_order = value - 1;
         break;
-    case TIFF_PAL:
+    case TIFF_PAL: {
         pal = (uint32_t *) s->palette;
         off = type_sizes[type];
-        if (count / 3 > 256 || bytestream2_get_bytes_left(&s->gb) < count / 3 * off * 3)
+        if (count / 3 > 256 ||
+            bytestream2_get_bytes_left(&s->gb) < count / 3 * off * 3)
             return -1;
+
         off = (type_sizes[type] - 1) << 3;
         for (k = 2; k >= 0; k--) {
             for (i = 0; i < count / 3; i++) {
@@ -870,6 +875,7 @@ static int tiff_decode_tag(TiffContext *s)
         }
         s->palette_is_set = 1;
         break;
+    }
     case TIFF_PLANAR:
         if (value == 2) {
             av_log(s->avctx, AV_LOG_ERROR, "Planar format is not supported\n");
@@ -1119,12 +1125,14 @@ static int decode_frame(AVCodecContext *avctx,
     if (s->stripsizesoff) {
         if (s->stripsizesoff >= (unsigned)avpkt->size)
             return AVERROR_INVALIDDATA;
-        bytestream2_init(&stripsizes, avpkt->data + s->stripsizesoff, avpkt->size - s->stripsizesoff);
+        bytestream2_init(&stripsizes, avpkt->data + s->stripsizesoff,
+                         avpkt->size - s->stripsizesoff);
     }
     if (s->strippos) {
         if (s->strippos >= (unsigned)avpkt->size)
             return AVERROR_INVALIDDATA;
-        bytestream2_init(&stripdata, avpkt->data + s->strippos, avpkt->size - s->strippos);
+        bytestream2_init(&stripdata, avpkt->data + s->strippos,
+                         avpkt->size - s->strippos);
     }
 
     if (s->rps <= 0) {
@@ -1134,12 +1142,12 @@ static int decode_frame(AVCodecContext *avctx,
 
     for (i = 0; i < s->height; i += s->rps) {
         if (s->stripsizesoff)
-            ssize = tget(&stripsizes, s->sstype, s->le);
+            ssize = tget(&stripsizes, s->sstype, le);
         else
             ssize = s->stripsize;
 
         if (s->strippos)
-            soff = tget(&stripdata, s->sot, s->le);
+            soff = tget(&stripdata, s->sot, le);
         else
             soff = s->stripoff;