Patches for the following CVE IDs:

CVE-2018-25009
CVE-2018-25010
CVE-2018-25011
CVE-2020-36328
CVE-2018-25013
CVE-2018-25014
CVE-2020-36328
CVE-2020-36329
CVE-2020-36330
CVE-2020-36331
CVE-2020-36332

Comprised of the following upstream commits:
1344a2e947c749d231141a295327e5b99b444d63
2c70ad76c94db5427d37ab4b85dc89b94dd75e01
39cb9aad85ca7bb1d193013460db1f8cc6bff109
569001f19fc81fcb5ab358f587a54c62e7c4665c
907208f97ead639bd521cf355a2f203f462eade6
95fd65070662e01cc9170c4444f5c0859a710097
be738c6d396fa5a272c1b209be4379a7532debfe
dad31750e374eff8e02fb467eb562d4bf236ed6e
dce5d7643177633ebe3513af492ea8c08c299cf3
eb82ce76ddca13ad6fb13376bb58b9fd3f850e9e

--- libwebp-0.6.1.orig/src/dec/buffer_dec.c
+++ libwebp-0.6.1/src/dec/buffer_dec.c
@@ -74,7 +74,8 @@ static VP8StatusCode CheckDecBuffer(cons
   } else {    // RGB checks
     const WebPRGBABuffer* const buf = &buffer->u.RGBA;
     const int stride = abs(buf->stride);
-    const uint64_t size = MIN_BUFFER_SIZE(width, height, stride);
+    const uint64_t size =
+        MIN_BUFFER_SIZE(width * kModeBpp[mode], height, stride);
     ok &= (size <= buf->size);
     ok &= (stride >= width * kModeBpp[mode]);
     ok &= (buf->rgba != NULL);
--- libwebp-0.6.1.orig/src/dec/idec_dec.c
+++ libwebp-0.6.1/src/dec/idec_dec.c
@@ -283,10 +283,8 @@ static void RestoreContext(const MBConte
 
 static VP8StatusCode IDecError(WebPIDecoder* const idec, VP8StatusCode error) {
   if (idec->state_ == STATE_VP8_DATA) {
-    VP8Io* const io = &idec->io_;
-    if (io->teardown != NULL) {
-      io->teardown(io);
-    }
+    // Synchronize the thread, clean-up and check for errors.
+    VP8ExitCritical((VP8Decoder*)idec->dec_, &idec->io_);
   }
   idec->state_ = STATE_ERROR;
   return error;
@@ -473,6 +471,12 @@ static VP8StatusCode DecodeRemaining(Web
             MemDataSize(&idec->mem_) > MAX_MB_SIZE) {
           return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR);
         }
+        // Synchronize the threads.
+        if (dec->mt_method_ > 0) {
+          if (!WebPGetWorkerInterface()->Sync(&dec->worker_)) {
+            return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR);
+          }
+        }
         RestoreContext(&context, dec, token_br);
         return VP8_STATUS_SUSPENDED;
       }
--- libwebp-0.6.1.orig/src/dec/vp8l_dec.c
+++ libwebp-0.6.1/src/dec/vp8l_dec.c
@@ -362,12 +362,19 @@ static int ReadHuffmanCodes(VP8LDecoder*
   VP8LMetadata* const hdr = &dec->hdr_;
   uint32_t* huffman_image = NULL;
   HTreeGroup* htree_groups = NULL;
+  // When reading htrees, some might be unused, as the format allows it.
+  // We will still read them but put them in this htree_group_bogus.
+  HTreeGroup htree_group_bogus;
   HuffmanCode* huffman_tables = NULL;
+  HuffmanCode* huffman_tables_bogus = NULL;
   HuffmanCode* next = NULL;
   int num_htree_groups = 1;
+  int num_htree_groups_max = 1;
   int max_alphabet_size = 0;
   int* code_lengths = NULL;
   const int table_size = kTableSize[color_cache_bits];
+  int* mapping = NULL;
+  int ok = 0;
 
   if (allow_recursion && VP8LReadBits(br, 1)) {
     // use meta Huffman codes.
@@ -384,10 +391,42 @@ static int ReadHuffmanCodes(VP8LDecoder*
       // The huffman data is stored in red and green bytes.
       const int group = (huffman_image[i] >> 8) & 0xffff;
       huffman_image[i] = group;
-      if (group >= num_htree_groups) {
-        num_htree_groups = group + 1;
+      if (group >= num_htree_groups_max) {
+        num_htree_groups_max = group + 1;
       }
     }
+    // Check the validity of num_htree_groups_max. If it seems too big, use a
+    // smaller value for later. This will prevent big memory allocations to end
+    // up with a bad bitstream anyway.
+    // The value of 1000 is totally arbitrary. We know that num_htree_groups_max
+    // is smaller than (1 << 16) and should be smaller than the number of pixels
+    // (though the format allows it to be bigger).
+    if (num_htree_groups_max > 1000 || num_htree_groups_max > xsize * ysize) {
+      // Create a mapping from the used indices to the minimal set of used
+      // values [0, num_htree_groups)
+      mapping = (int*)WebPSafeMalloc(num_htree_groups_max, sizeof(*mapping));
+      if (mapping == NULL) {
+        dec->status_ = VP8_STATUS_OUT_OF_MEMORY;
+        goto Error;
+      }
+      // -1 means a value is unmapped, and therefore unused in the Huffman
+      // image.
+      memset(mapping, 0xff, num_htree_groups_max * sizeof(*mapping));
+      for (num_htree_groups = 0, i = 0; i < huffman_pixs; ++i) {
+        // Get the current mapping for the group and remap the Huffman image.
+        int* const mapped_group = &mapping[huffman_image[i]];
+        if (*mapped_group == -1) *mapped_group = num_htree_groups++;
+        huffman_image[i] = *mapped_group;
+      }
+      huffman_tables_bogus = (HuffmanCode*)WebPSafeMalloc(
+          table_size, sizeof(*huffman_tables_bogus));
+      if (huffman_tables_bogus == NULL) {
+        dec->status_ = VP8_STATUS_OUT_OF_MEMORY;
+        goto Error;
+      }
+    } else {
+      num_htree_groups = num_htree_groups_max;
+    }
   }
 
   if (br->eos_) goto Error;
@@ -403,11 +442,11 @@ static int ReadHuffmanCodes(VP8LDecoder*
     }
   }
 
+  code_lengths = (int*)WebPSafeCalloc((uint64_t)max_alphabet_size,
+                                      sizeof(*code_lengths));
   huffman_tables = (HuffmanCode*)WebPSafeMalloc(num_htree_groups * table_size,
                                                 sizeof(*huffman_tables));
   htree_groups = VP8LHtreeGroupsNew(num_htree_groups);
-  code_lengths = (int*)WebPSafeCalloc((uint64_t)max_alphabet_size,
-                                      sizeof(*code_lengths));
 
   if (htree_groups == NULL || code_lengths == NULL || huffman_tables == NULL) {
     dec->status_ = VP8_STATUS_OUT_OF_MEMORY;
@@ -415,28 +454,35 @@ static int ReadHuffmanCodes(VP8LDecoder*
   }
 
   next = huffman_tables;
-  for (i = 0; i < num_htree_groups; ++i) {
-    HTreeGroup* const htree_group = &htree_groups[i];
+  for (i = 0; i < num_htree_groups_max; ++i) {
+    // If the index "i" is unused in the Huffman image, read the coefficients
+    // but store them to a bogus htree_group.
+    const int is_bogus = (mapping != NULL && mapping[i] == -1);
+    HTreeGroup* const htree_group =
+        is_bogus ? &htree_group_bogus :
+        &htree_groups[(mapping == NULL) ? i : mapping[i]];
     HuffmanCode** const htrees = htree_group->htrees;
+    HuffmanCode* huffman_tables_i = is_bogus ? huffman_tables_bogus : next;
     int size;
     int total_size = 0;
     int is_trivial_literal = 1;
     int max_bits = 0;
     for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; ++j) {
       int alphabet_size = kAlphabetSize[j];
-      htrees[j] = next;
+      htrees[j] = huffman_tables_i;
       if (j == 0 && color_cache_bits > 0) {
         alphabet_size += 1 << color_cache_bits;
       }
-      size = ReadHuffmanCode(alphabet_size, dec, code_lengths, next);
+      size =
+          ReadHuffmanCode(alphabet_size, dec, code_lengths, huffman_tables_i);
       if (size == 0) {
         goto Error;
       }
       if (is_trivial_literal && kLiteralMap[j] == 1) {
-        is_trivial_literal = (next->bits == 0);
+        is_trivial_literal = (huffman_tables_i->bits == 0);
       }
-      total_size += next->bits;
-      next += size;
+      total_size += huffman_tables_i->bits;
+      huffman_tables_i += size;
       if (j <= ALPHA) {
         int local_max_bits = code_lengths[0];
         int k;
@@ -448,38 +494,41 @@ static int ReadHuffmanCodes(VP8LDecoder*
         max_bits += local_max_bits;
       }
     }
+    if (!is_bogus) next = huffman_tables_i;
     htree_group->is_trivial_literal = is_trivial_literal;
     htree_group->is_trivial_code = 0;
     if (is_trivial_literal) {
       const int red = htrees[RED][0].value;
       const int blue = htrees[BLUE][0].value;
       const int alpha = htrees[ALPHA][0].value;
-      htree_group->literal_arb =
-          ((uint32_t)alpha << 24) | (red << 16) | blue;
+      htree_group->literal_arb = ((uint32_t)alpha << 24) | (red << 16) | blue;
       if (total_size == 0 && htrees[GREEN][0].value < NUM_LITERAL_CODES) {
         htree_group->is_trivial_code = 1;
         htree_group->literal_arb |= htrees[GREEN][0].value << 8;
       }
     }
-    htree_group->use_packed_table = !htree_group->is_trivial_code &&
-                                    (max_bits < HUFFMAN_PACKED_BITS);
+    htree_group->use_packed_table =
+        !htree_group->is_trivial_code && (max_bits < HUFFMAN_PACKED_BITS);
     if (htree_group->use_packed_table) BuildPackedTable(htree_group);
   }
-  WebPSafeFree(code_lengths);
+  ok = 1;
 
-  // All OK. Finalize pointers and return.
+  // All OK. Finalize pointers.
   hdr->huffman_image_ = huffman_image;
   hdr->num_htree_groups_ = num_htree_groups;
   hdr->htree_groups_ = htree_groups;
   hdr->huffman_tables_ = huffman_tables;
-  return 1;
 
  Error:
   WebPSafeFree(code_lengths);
-  WebPSafeFree(huffman_image);
-  WebPSafeFree(huffman_tables);
-  VP8LHtreeGroupsFree(htree_groups);
-  return 0;
+  WebPSafeFree(huffman_tables_bogus);
+  WebPSafeFree(mapping);
+  if (!ok) {
+    WebPSafeFree(huffman_image);
+    WebPSafeFree(huffman_tables);
+    VP8LHtreeGroupsFree(htree_groups);
+  }
+  return ok;
 }
 
 //------------------------------------------------------------------------------
--- libwebp-0.6.1.orig/src/mux/muxi.h
+++ libwebp-0.6.1/src/mux/muxi.h
@@ -14,6 +14,7 @@
 #ifndef WEBP_MUX_MUXI_H_
 #define WEBP_MUX_MUXI_H_
 
+#include <assert.h>
 #include <stdlib.h>
 #include "src/dec/vp8i_dec.h"
 #include "src/dec/vp8li_dec.h"
@@ -143,13 +144,13 @@ void ChunkListDelete(WebPChunk** const c
 
 // Returns size of the chunk including chunk header and padding byte (if any).
 static WEBP_INLINE size_t SizeWithPadding(size_t chunk_size) {
+  assert(chunk_size <= MAX_CHUNK_PAYLOAD);
   return CHUNK_HEADER_SIZE + ((chunk_size + 1) & ~1U);
 }
 
 // Size of a chunk including header and padding.
 static WEBP_INLINE size_t ChunkDiskSize(const WebPChunk* chunk) {
   const size_t data_size = chunk->data_.size;
-  assert(data_size < MAX_CHUNK_PAYLOAD);
   return SizeWithPadding(data_size);
 }
 
--- libwebp-0.6.1.orig/src/mux/muxread.c
+++ libwebp-0.6.1/src/mux/muxread.c
@@ -59,6 +59,7 @@ static WebPMuxError ChunkVerifyAndAssign
   // Sanity checks.
   if (data_size < CHUNK_HEADER_SIZE) return WEBP_MUX_NOT_ENOUGH_DATA;
   chunk_size = GetLE32(data + TAG_SIZE);
+  if (chunk_size > MAX_CHUNK_PAYLOAD) return WEBP_MUX_BAD_DATA;
 
   {
     const size_t chunk_disk_size = SizeWithPadding(chunk_size);
@@ -137,6 +138,7 @@ static int MuxImageParse(const WebPChunk
         wpi->is_partial_ = 1;  // Waiting for a VP8 chunk.
         break;
       case WEBP_CHUNK_IMAGE:
+        if (wpi->img_ != NULL) goto Fail;  // Only 1 image chunk allowed.
         if (ChunkSetNth(&subchunk, &wpi->img_, 1) != WEBP_MUX_OK) goto Fail;
         if (!MuxImageFinalize(wpi)) goto Fail;
         wpi->is_partial_ = 0;  // wpi is completely filled.
@@ -187,7 +189,7 @@ WebPMux* WebPMuxCreateInternal(const Web
   size = bitstream->size;
 
   if (data == NULL) return NULL;
-  if (size < RIFF_HEADER_SIZE) return NULL;
+  if (size < RIFF_HEADER_SIZE + CHUNK_HEADER_SIZE) return NULL;
   if (GetLE32(data + 0) != MKFOURCC('R', 'I', 'F', 'F') ||
       GetLE32(data + CHUNK_HEADER_SIZE) != MKFOURCC('W', 'E', 'B', 'P')) {
     return NULL;
@@ -196,8 +198,6 @@ WebPMux* WebPMuxCreateInternal(const Web
   mux = WebPMuxNew();
   if (mux == NULL) return NULL;
 
-  if (size < RIFF_HEADER_SIZE + TAG_SIZE) goto Err;
-
   tag = GetLE32(data + RIFF_HEADER_SIZE);
   if (tag != kChunks[IDX_VP8].tag &&
       tag != kChunks[IDX_VP8L].tag &&
@@ -205,13 +205,17 @@ WebPMux* WebPMuxCreateInternal(const Web
     goto Err;  // First chunk should be VP8, VP8L or VP8X.
   }
 
-  riff_size = SizeWithPadding(GetLE32(data + TAG_SIZE));
-  if (riff_size > MAX_CHUNK_PAYLOAD || riff_size > size) {
-    goto Err;
-  } else {
-    if (riff_size < size) {  // Redundant data after last chunk.
-      size = riff_size;  // To make sure we don't read any data beyond mux_size.
-    }
+  riff_size = GetLE32(data + TAG_SIZE);
+  if (riff_size > MAX_CHUNK_PAYLOAD) goto Err;
+
+  // Note this padding is historical and differs from demux.c which does not
+  // pad the file size.
+  riff_size = SizeWithPadding(riff_size);
+  if (riff_size < CHUNK_HEADER_SIZE) goto Err;
+  if (riff_size > size) goto Err;
+  // There's no point in reading past the end of the RIFF chunk.
+  if (size > riff_size + CHUNK_HEADER_SIZE) {
+    size = riff_size + CHUNK_HEADER_SIZE;
   }
 
   end = data + size;
@@ -260,6 +264,7 @@ WebPMux* WebPMuxCreateInternal(const Web
         chunk_list = MuxGetChunkListFromId(mux, id);  // List to add this chunk.
         if (ChunkSetNth(&chunk, chunk_list, 0) != WEBP_MUX_OK) goto Err;
         if (id == WEBP_CHUNK_VP8X) {  // grab global specs
+          if (data_size < CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE) goto Err;
           mux->canvas_width_ = GetLE24(data + 12) + 1;
           mux->canvas_height_ = GetLE24(data + 15) + 1;
         }
--- libwebp-0.6.1.orig/src/utils/quant_levels_dec_utils.c
+++ libwebp-0.6.1/src/utils/quant_levels_dec_utils.c
@@ -261,9 +261,15 @@ static void CleanupParams(SmoothParams*
 
 int WebPDequantizeLevels(uint8_t* const data, int width, int height, int stride,
                          int strength) {
-  const int radius = 4 * strength / 100;
+  int radius = 4 * strength / 100;
+
   if (strength < 0 || strength > 100) return 0;
   if (data == NULL || width <= 0 || height <= 0) return 0;  // bad params
+
+  // limit the filter size to not exceed the image dimensions
+  if (2 * radius + 1 > width) radius = (width - 1) >> 1;
+  if (2 * radius + 1 > height) radius = (height - 1) >> 1;
+
   if (radius > 0) {
     SmoothParams p;
     memset(&p, 0, sizeof(p));
