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firefox/CVE-2023-4863-1.patch
Jiayi Yin 3f5b6d926c init
2025-03-17 09:32:30 +00:00

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# HG changeset patch
# User Ryan VanderMeulen <ryanvm@gmail.com>
# Date 1694477965 14400
# Node ID 96bd93fca47ae72ff0385d2bd87ec7bd18382b0c
# Parent 0f605d803733000f3e1fcc3a22c2d53190305314
Bug 1852649 - Cherry-pick upstream libwebp fix. r=tnikkel, a=RyanVM
Backport of:
https://chromium.googlesource.com/webm/libwebp.git/+/2af26267cdfcb63a88e5c74a85927a12d6ca1d76
Differential Revision: https://phabricator.services.mozilla.com/D187950
diff --git a/media/libwebp/src/dec/vp8l_dec.c b/media/libwebp/src/dec/vp8l_dec.c
--- a/media/libwebp/src/dec/vp8l_dec.c
+++ b/media/libwebp/src/dec/vp8l_dec.c
@@ -248,21 +248,21 @@ static void BuildPackedTable(HTreeGroup*
static int ReadHuffmanCodeLengths(
VP8LDecoder* const dec, const int* const code_length_code_lengths,
int num_symbols, int* const code_lengths) {
int ok = 0;
VP8LBitReader* const br = &dec->br_;
int symbol;
int max_symbol;
int prev_code_len = DEFAULT_CODE_LENGTH;
- HuffmanCode table[1 << LENGTHS_TABLE_BITS];
+ HuffmanTables tables;
- if (!VP8LBuildHuffmanTable(table, LENGTHS_TABLE_BITS,
- code_length_code_lengths,
- NUM_CODE_LENGTH_CODES)) {
+ if (!VP8LHuffmanTablesAllocate(1 << LENGTHS_TABLE_BITS, &tables) ||
+ !VP8LBuildHuffmanTable(&tables, LENGTHS_TABLE_BITS,
+ code_length_code_lengths, NUM_CODE_LENGTH_CODES)) {
goto End;
}
if (VP8LReadBits(br, 1)) { // use length
const int length_nbits = 2 + 2 * VP8LReadBits(br, 3);
max_symbol = 2 + VP8LReadBits(br, length_nbits);
if (max_symbol > num_symbols) {
goto End;
@@ -272,17 +272,17 @@ static int ReadHuffmanCodeLengths(
}
symbol = 0;
while (symbol < num_symbols) {
const HuffmanCode* p;
int code_len;
if (max_symbol-- == 0) break;
VP8LFillBitWindow(br);
- p = &table[VP8LPrefetchBits(br) & LENGTHS_TABLE_MASK];
+ p = &tables.curr_segment->start[VP8LPrefetchBits(br) & LENGTHS_TABLE_MASK];
VP8LSetBitPos(br, br->bit_pos_ + p->bits);
code_len = p->value;
if (code_len < kCodeLengthLiterals) {
code_lengths[symbol++] = code_len;
if (code_len != 0) prev_code_len = code_len;
} else {
const int use_prev = (code_len == kCodeLengthRepeatCode);
const int slot = code_len - kCodeLengthLiterals;
@@ -295,24 +295,26 @@ static int ReadHuffmanCodeLengths(
const int length = use_prev ? prev_code_len : 0;
while (repeat-- > 0) code_lengths[symbol++] = length;
}
}
}
ok = 1;
End:
+ VP8LHuffmanTablesDeallocate(&tables);
if (!ok) dec->status_ = VP8_STATUS_BITSTREAM_ERROR;
return ok;
}
// 'code_lengths' is pre-allocated temporary buffer, used for creating Huffman
// tree.
static int ReadHuffmanCode(int alphabet_size, VP8LDecoder* const dec,
- int* const code_lengths, HuffmanCode* const table) {
+ int* const code_lengths,
+ HuffmanTables* const table) {
int ok = 0;
int size = 0;
VP8LBitReader* const br = &dec->br_;
const int simple_code = VP8LReadBits(br, 1);
memset(code_lengths, 0, alphabet_size * sizeof(*code_lengths));
if (simple_code) { // Read symbols, codes & code lengths directly.
@@ -357,26 +359,29 @@ static int ReadHuffmanCode(int alphabet_
static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
int color_cache_bits, int allow_recursion) {
int i, j;
VP8LBitReader* const br = &dec->br_;
VP8LMetadata* const hdr = &dec->hdr_;
uint32_t* huffman_image = NULL;
HTreeGroup* htree_groups = NULL;
- HuffmanCode* huffman_tables = NULL;
- HuffmanCode* huffman_table = NULL;
+ HuffmanTables* huffman_tables = &hdr->huffman_tables_;
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;
+ // Check the table has been 0 initialized (through InitMetadata).
+ assert(huffman_tables->root.start == NULL);
+ assert(huffman_tables->curr_segment == NULL);
+
if (allow_recursion && VP8LReadBits(br, 1)) {
// use meta Huffman codes.
const int huffman_precision = VP8LReadBits(br, 3) + 2;
const int huffman_xsize = VP8LSubSampleSize(xsize, huffman_precision);
const int huffman_ysize = VP8LSubSampleSize(ysize, huffman_precision);
const int huffman_pixs = huffman_xsize * huffman_ysize;
if (!DecodeImageStream(huffman_xsize, huffman_ysize, 0, dec,
&huffman_image)) {
@@ -429,26 +434,25 @@ static int ReadHuffmanCodes(VP8LDecoder*
}
if (max_alphabet_size < alphabet_size) {
max_alphabet_size = alphabet_size;
}
}
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);
- if (htree_groups == NULL || code_lengths == NULL || huffman_tables == NULL) {
+ if (htree_groups == NULL || code_lengths == NULL ||
+ !VP8LHuffmanTablesAllocate(num_htree_groups * table_size,
+ huffman_tables)) {
dec->status_ = VP8_STATUS_OUT_OF_MEMORY;
goto Error;
}
- huffman_table = huffman_tables;
for (i = 0; i < num_htree_groups_max; ++i) {
// If the index "i" is unused in the Huffman image, just make sure the
// coefficients are valid but do not store them.
if (mapping != NULL && mapping[i] == -1) {
for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; ++j) {
int alphabet_size = kAlphabetSize[j];
if (j == 0 && color_cache_bits > 0) {
alphabet_size += (1 << color_cache_bits);
@@ -463,29 +467,30 @@ static int ReadHuffmanCodes(VP8LDecoder*
&htree_groups[(mapping == NULL) ? i : mapping[i]];
HuffmanCode** const htrees = htree_group->htrees;
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] = huffman_table;
if (j == 0 && color_cache_bits > 0) {
alphabet_size += (1 << color_cache_bits);
}
- size = ReadHuffmanCode(alphabet_size, dec, code_lengths, huffman_table);
+ size =
+ ReadHuffmanCode(alphabet_size, dec, code_lengths, huffman_tables);
+ htrees[j] = huffman_tables->curr_segment->curr_table;
if (size == 0) {
goto Error;
}
if (is_trivial_literal && kLiteralMap[j] == 1) {
- is_trivial_literal = (huffman_table->bits == 0);
+ is_trivial_literal = (htrees[j]->bits == 0);
}
- total_size += huffman_table->bits;
- huffman_table += size;
+ total_size += htrees[j]->bits;
+ huffman_tables->curr_segment->curr_table += size;
if (j <= ALPHA) {
int local_max_bits = code_lengths[0];
int k;
for (k = 1; k < alphabet_size; ++k) {
if (code_lengths[k] > local_max_bits) {
local_max_bits = code_lengths[k];
}
}
@@ -510,24 +515,23 @@ static int ReadHuffmanCodes(VP8LDecoder*
}
}
ok = 1;
// 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;
Error:
WebPSafeFree(code_lengths);
WebPSafeFree(mapping);
if (!ok) {
WebPSafeFree(huffman_image);
- WebPSafeFree(huffman_tables);
+ VP8LHuffmanTablesDeallocate(huffman_tables);
VP8LHtreeGroupsFree(htree_groups);
}
return ok;
}
//------------------------------------------------------------------------------
// Scaling.
@@ -1353,17 +1357,17 @@ static void InitMetadata(VP8LMetadata* c
assert(hdr != NULL);
memset(hdr, 0, sizeof(*hdr));
}
static void ClearMetadata(VP8LMetadata* const hdr) {
assert(hdr != NULL);
WebPSafeFree(hdr->huffman_image_);
- WebPSafeFree(hdr->huffman_tables_);
+ VP8LHuffmanTablesDeallocate(&hdr->huffman_tables_);
VP8LHtreeGroupsFree(hdr->htree_groups_);
VP8LColorCacheClear(&hdr->color_cache_);
VP8LColorCacheClear(&hdr->saved_color_cache_);
InitMetadata(hdr);
}
// -----------------------------------------------------------------------------
// VP8LDecoder
@@ -1668,17 +1672,17 @@ int VP8LDecodeHeader(VP8LDecoder* const
}
int VP8LDecodeImage(VP8LDecoder* const dec) {
VP8Io* io = NULL;
WebPDecParams* params = NULL;
if (dec == NULL) return 0;
- assert(dec->hdr_.huffman_tables_ != NULL);
+ assert(dec->hdr_.huffman_tables_.root.start != NULL);
assert(dec->hdr_.htree_groups_ != NULL);
assert(dec->hdr_.num_htree_groups_ > 0);
io = dec->io_;
assert(io != NULL);
params = (WebPDecParams*)io->opaque;
assert(params != NULL);
diff --git a/media/libwebp/src/dec/vp8li_dec.h b/media/libwebp/src/dec/vp8li_dec.h
--- a/media/libwebp/src/dec/vp8li_dec.h
+++ b/media/libwebp/src/dec/vp8li_dec.h
@@ -46,17 +46,17 @@ typedef struct {
VP8LColorCache saved_color_cache_; // for incremental
int huffman_mask_;
int huffman_subsample_bits_;
int huffman_xsize_;
uint32_t* huffman_image_;
int num_htree_groups_;
HTreeGroup* htree_groups_;
- HuffmanCode* huffman_tables_;
+ HuffmanTables huffman_tables_;
} VP8LMetadata;
typedef struct VP8LDecoder VP8LDecoder;
struct VP8LDecoder {
VP8StatusCode status_;
VP8LDecodeState state_;
VP8Io* io_;
diff --git a/media/libwebp/src/utils/huffman_utils.c b/media/libwebp/src/utils/huffman_utils.c
--- a/media/libwebp/src/utils/huffman_utils.c
+++ b/media/libwebp/src/utils/huffman_utils.c
@@ -172,31 +172,34 @@ static int BuildHuffmanTable(HuffmanCode
for (len = root_bits + 1, step = 2; len <= MAX_ALLOWED_CODE_LENGTH;
++len, step <<= 1) {
num_open <<= 1;
num_nodes += num_open;
num_open -= count[len];
if (num_open < 0) {
return 0;
}
- if (root_table == NULL) continue;
for (; count[len] > 0; --count[len]) {
HuffmanCode code;
if ((key & mask) != low) {
- table += table_size;
+ if (root_table != NULL) table += table_size;
table_bits = NextTableBitSize(count, len, root_bits);
table_size = 1 << table_bits;
total_size += table_size;
low = key & mask;
- root_table[low].bits = (uint8_t)(table_bits + root_bits);
- root_table[low].value = (uint16_t)((table - root_table) - low);
+ if (root_table != NULL) {
+ root_table[low].bits = (uint8_t)(table_bits + root_bits);
+ root_table[low].value = (uint16_t)((table - root_table) - low);
+ }
}
- code.bits = (uint8_t)(len - root_bits);
- code.value = (uint16_t)sorted[symbol++];
- ReplicateValue(&table[key >> root_bits], step, table_size, code);
+ if (root_table != NULL) {
+ code.bits = (uint8_t)(len - root_bits);
+ code.value = (uint16_t)sorted[symbol++];
+ ReplicateValue(&table[key >> root_bits], step, table_size, code);
+ }
key = GetNextKey(key, len);
}
}
// Check if tree is full.
if (num_nodes != 2 * offset[MAX_ALLOWED_CODE_LENGTH] - 1) {
return 0;
}
@@ -206,30 +209,88 @@ static int BuildHuffmanTable(HuffmanCode
}
// Maximum code_lengths_size is 2328 (reached for 11-bit color_cache_bits).
// More commonly, the value is around ~280.
#define MAX_CODE_LENGTHS_SIZE \
((1 << MAX_CACHE_BITS) + NUM_LITERAL_CODES + NUM_LENGTH_CODES)
// Cut-off value for switching between heap and stack allocation.
#define SORTED_SIZE_CUTOFF 512
-int VP8LBuildHuffmanTable(HuffmanCode* const root_table, int root_bits,
+int VP8LBuildHuffmanTable(HuffmanTables* const root_table, int root_bits,
const int code_lengths[], int code_lengths_size) {
- int total_size;
+ const int total_size =
+ BuildHuffmanTable(NULL, root_bits, code_lengths, code_lengths_size, NULL);
assert(code_lengths_size <= MAX_CODE_LENGTHS_SIZE);
- if (root_table == NULL) {
- total_size = BuildHuffmanTable(NULL, root_bits,
- code_lengths, code_lengths_size, NULL);
- } else if (code_lengths_size <= SORTED_SIZE_CUTOFF) {
+ if (total_size == 0 || root_table == NULL) return total_size;
+
+ if (root_table->curr_segment->curr_table + total_size >=
+ root_table->curr_segment->start + root_table->curr_segment->size) {
+ // If 'root_table' does not have enough memory, allocate a new segment.
+ // The available part of root_table->curr_segment is left unused because we
+ // need a contiguous buffer.
+ const int segment_size = root_table->curr_segment->size;
+ struct HuffmanTablesSegment* next =
+ (HuffmanTablesSegment*)WebPSafeMalloc(1, sizeof(*next));
+ if (next == NULL) return 0;
+ // Fill the new segment.
+ // We need at least 'total_size' but if that value is small, it is better to
+ // allocate a big chunk to prevent more allocations later. 'segment_size' is
+ // therefore chosen (any other arbitrary value could be chosen).
+ next->size = total_size > segment_size ? total_size : segment_size;
+ next->start =
+ (HuffmanCode*)WebPSafeMalloc(next->size, sizeof(*next->start));
+ if (next->start == NULL) {
+ WebPSafeFree(next);
+ return 0;
+ }
+ next->curr_table = next->start;
+ next->next = NULL;
+ // Point to the new segment.
+ root_table->curr_segment->next = next;
+ root_table->curr_segment = next;
+ }
+ if (code_lengths_size <= SORTED_SIZE_CUTOFF) {
// use local stack-allocated array.
uint16_t sorted[SORTED_SIZE_CUTOFF];
- total_size = BuildHuffmanTable(root_table, root_bits,
- code_lengths, code_lengths_size, sorted);
- } else { // rare case. Use heap allocation.
+ BuildHuffmanTable(root_table->curr_segment->curr_table, root_bits,
+ code_lengths, code_lengths_size, sorted);
+ } else { // rare case. Use heap allocation.
uint16_t* const sorted =
(uint16_t*)WebPSafeMalloc(code_lengths_size, sizeof(*sorted));
if (sorted == NULL) return 0;
- total_size = BuildHuffmanTable(root_table, root_bits,
- code_lengths, code_lengths_size, sorted);
+ BuildHuffmanTable(root_table->curr_segment->curr_table, root_bits,
+ code_lengths, code_lengths_size, sorted);
WebPSafeFree(sorted);
}
return total_size;
}
+
+int VP8LHuffmanTablesAllocate(int size, HuffmanTables* huffman_tables) {
+ // Have 'segment' point to the first segment for now, 'root'.
+ HuffmanTablesSegment* const root = &huffman_tables->root;
+ huffman_tables->curr_segment = root;
+ // Allocate root.
+ root->start = (HuffmanCode*)WebPSafeMalloc(size, sizeof(*root->start));
+ if (root->start == NULL) return 0;
+ root->curr_table = root->start;
+ root->next = NULL;
+ root->size = size;
+ return 1;
+}
+
+void VP8LHuffmanTablesDeallocate(HuffmanTables* const huffman_tables) {
+ HuffmanTablesSegment *current, *next;
+ if (huffman_tables == NULL) return;
+ // Free the root node.
+ current = &huffman_tables->root;
+ next = current->next;
+ WebPSafeFree(current->start);
+ current->start = NULL;
+ current->next = NULL;
+ current = next;
+ // Free the following nodes.
+ while (current != NULL) {
+ next = current->next;
+ WebPSafeFree(current->start);
+ WebPSafeFree(current);
+ current = next;
+ }
+}
diff --git a/media/libwebp/src/utils/huffman_utils.h b/media/libwebp/src/utils/huffman_utils.h
--- a/media/libwebp/src/utils/huffman_utils.h
+++ b/media/libwebp/src/utils/huffman_utils.h
@@ -38,16 +38,39 @@ typedef struct {
// long version for holding 32b values
typedef struct {
int bits; // number of bits used for this symbol,
// or an impossible value if not a literal code.
uint32_t value; // 32b packed ARGB value if literal,
// or non-literal symbol otherwise
} HuffmanCode32;
+// Contiguous memory segment of HuffmanCodes.
+typedef struct HuffmanTablesSegment {
+ HuffmanCode* start;
+ // Pointer to where we are writing into the segment. Starts at 'start' and
+ // cannot go beyond 'start' + 'size'.
+ HuffmanCode* curr_table;
+ // Pointer to the next segment in the chain.
+ struct HuffmanTablesSegment* next;
+ int size;
+} HuffmanTablesSegment;
+
+// Chained memory segments of HuffmanCodes.
+typedef struct HuffmanTables {
+ HuffmanTablesSegment root;
+ // Currently processed segment. At first, this is 'root'.
+ HuffmanTablesSegment* curr_segment;
+} HuffmanTables;
+
+// Allocates a HuffmanTables with 'size' contiguous HuffmanCodes. Returns 0 on
+// memory allocation error, 1 otherwise.
+int VP8LHuffmanTablesAllocate(int size, HuffmanTables* huffman_tables);
+void VP8LHuffmanTablesDeallocate(HuffmanTables* const huffman_tables);
+
#define HUFFMAN_PACKED_BITS 6
#define HUFFMAN_PACKED_TABLE_SIZE (1u << HUFFMAN_PACKED_BITS)
// Huffman table group.
// Includes special handling for the following cases:
// - is_trivial_literal: one common literal base for RED/BLUE/ALPHA (not GREEN)
// - is_trivial_code: only 1 code (no bit is read from bitstream)
// - use_packed_table: few enough literal symbols, so all the bit codes
@@ -73,18 +96,16 @@ HTreeGroup* VP8LHtreeGroupsNew(int num_h
// Releases the memory allocated for HTreeGroup.
void VP8LHtreeGroupsFree(HTreeGroup* const htree_groups);
// Builds Huffman lookup table assuming code lengths are in symbol order.
// The 'code_lengths' is pre-allocated temporary memory buffer used for creating
// the huffman table.
// Returns built table size or 0 in case of error (invalid tree or
// memory error).
-// If root_table is NULL, it returns 0 if a lookup cannot be built, something
-// > 0 otherwise (but not the table size).
-int VP8LBuildHuffmanTable(HuffmanCode* const root_table, int root_bits,
+int VP8LBuildHuffmanTable(HuffmanTables* const root_table, int root_bits,
const int code_lengths[], int code_lengths_size);
#ifdef __cplusplus
} // extern "C"
#endif
#endif // WEBP_UTILS_HUFFMAN_UTILS_H_
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