From f62ea8f6517d162940fb1bbf34aa2236051262823d91af03b1bf8569bae8d92d Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Tue, 12 Sep 2023 12:53:40 +0000 Subject: [PATCH] - Add 0001-Fix-OOB-write-in-BuildHuffmanTable.patch [boo#1215231] [CVE-2023-4863] OBS-URL: https://build.opensuse.org/package/show/graphics/libwebp?expand=0&rev=35 --- 0001-Fix-OOB-write-in-BuildHuffmanTable.patch | 361 ++++++++++++++++++ libwebp.changes | 6 + libwebp.spec | 1 + 3 files changed, 368 insertions(+) create mode 100644 0001-Fix-OOB-write-in-BuildHuffmanTable.patch diff --git a/0001-Fix-OOB-write-in-BuildHuffmanTable.patch b/0001-Fix-OOB-write-in-BuildHuffmanTable.patch new file mode 100644 index 0000000..3a74ca4 --- /dev/null +++ b/0001-Fix-OOB-write-in-BuildHuffmanTable.patch @@ -0,0 +1,361 @@ +From 2af26267cdfcb63a88e5c74a85927a12d6ca1d76 Mon Sep 17 00:00:00 2001 +From: Vincent Rabaud +Date: Thu, 7 Sep 2023 21:16:03 +0200 +Subject: [PATCH] Fix OOB write in BuildHuffmanTable. + +First, BuildHuffmanTable is called to check if the data is valid. +If it is and the table is not big enough, more memory is allocated. + +This will make sure that valid (but unoptimized because of unbalanced +codes) streams are still decodable. + +Bug: chromium:1479274 +Change-Id: I31c36dbf3aa78d35ecf38706b50464fd3d375741 +(cherry picked from commit 902bc9190331343b2017211debcec8d2ab87e17a) +--- + src/dec/vp8l_dec.c | 46 ++++++++++--------- + src/dec/vp8li_dec.h | 2 +- + src/utils/huffman_utils.c | 97 +++++++++++++++++++++++++++++++-------- + src/utils/huffman_utils.h | 27 +++++++++-- + 4 files changed, 129 insertions(+), 43 deletions(-) + +diff --git a/src/dec/vp8l_dec.c b/src/dec/vp8l_dec.c +index c0ea0181..7995313f 100644 +--- a/src/dec/vp8l_dec.c ++++ b/src/dec/vp8l_dec.c +@@ -253,11 +253,11 @@ static int ReadHuffmanCodeLengths( + 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; + } + +@@ -277,7 +277,7 @@ static int ReadHuffmanCodeLengths( + 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) { +@@ -300,6 +300,7 @@ static int ReadHuffmanCodeLengths( + ok = 1; + + End: ++ VP8LHuffmanTablesDeallocate(&tables); + if (!ok) dec->status_ = VP8_STATUS_BITSTREAM_ERROR; + return ok; + } +@@ -307,7 +308,8 @@ static int ReadHuffmanCodeLengths( + // '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_; +@@ -362,8 +364,7 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize, + 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; +@@ -372,6 +373,10 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize, + 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; +@@ -434,16 +439,15 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize, + + 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. +@@ -468,19 +472,20 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize, + 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; +@@ -515,14 +520,13 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize, + 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; +@@ -1358,7 +1362,7 @@ 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_); +@@ -1673,7 +1677,7 @@ int VP8LDecodeImage(VP8LDecoder* const dec) { + + 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); + +diff --git a/src/dec/vp8li_dec.h b/src/dec/vp8li_dec.h +index 72b2e861..32540a4b 100644 +--- a/src/dec/vp8li_dec.h ++++ b/src/dec/vp8li_dec.h +@@ -51,7 +51,7 @@ typedef struct { + uint32_t* huffman_image_; + int num_htree_groups_; + HTreeGroup* htree_groups_; +- HuffmanCode* huffman_tables_; ++ HuffmanTables huffman_tables_; + } VP8LMetadata; + + typedef struct VP8LDecoder VP8LDecoder; +diff --git a/src/utils/huffman_utils.c b/src/utils/huffman_utils.c +index 90c2fbf7..cf73abd4 100644 +--- a/src/utils/huffman_utils.c ++++ b/src/utils/huffman_utils.c +@@ -177,21 +177,24 @@ static int BuildHuffmanTable(HuffmanCode* const root_table, int root_bits, + 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); ++ } ++ } ++ 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); + } +- 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); + } + } +@@ -211,25 +214,83 @@ static int BuildHuffmanTable(HuffmanCode* const root_table, int root_bits, + ((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/src/utils/huffman_utils.h b/src/utils/huffman_utils.h +index 13b7ad1a..98415c53 100644 +--- a/src/utils/huffman_utils.h ++++ b/src/utils/huffman_utils.h +@@ -43,6 +43,29 @@ typedef struct { + // 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) + +@@ -78,9 +101,7 @@ void VP8LHtreeGroupsFree(HTreeGroup* const htree_groups); + // 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 +-- +2.42.0 + diff --git a/libwebp.changes b/libwebp.changes index a33b990..94eebfb 100644 --- a/libwebp.changes +++ b/libwebp.changes @@ -1,3 +1,9 @@ +------------------------------------------------------------------- +Tue Sep 12 12:53:18 UTC 2023 - Jan Engelhardt + +- Add 0001-Fix-OOB-write-in-BuildHuffmanTable.patch + [boo#1215231] [CVE-2023-4863] + ------------------------------------------------------------------- Tue Jul 18 09:22:41 UTC 2023 - Dominique Leuenberger diff --git a/libwebp.spec b/libwebp.spec index e769aa1..8e05edb 100644 --- a/libwebp.spec +++ b/libwebp.spec @@ -28,6 +28,7 @@ Source: https://storage.googleapis.com/downloads.webmproject.org/release Source2: https://storage.googleapis.com/downloads.webmproject.org/releases/webp/libwebp-%version.tar.gz.asc Source3: %name.keyring Source4: baselibs.conf +Patch1: 0001-Fix-OOB-write-in-BuildHuffmanTable.patch BuildRequires: giflib-devel BuildRequires: pkgconfig