mirror/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2026-02-14 13:30:45 +00:00
Code Issues Packages Projects Releases Wiki Activity

std.compress.zstandard: improve block size validation

Browse Source
This commit is contained in:
dweiller 2023-02-06 13:19:24 +11:00
parent ece52e0771
commit 98bbd959b0
2 changed files with 8 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
lib/std/compress/zstandard/decode/block.zig
View File

@ -594,9 +594,9 @@ pub fn decodeBlock(
block_header: frame.Zstandard.Block.Header,
decode_state: *DecodeState,
consumed_count: *usize,
block_size_max: usize,
written_count: usize,
) (error{DestTooSmall} || Error)!usize {
const block_size_max = @min(1 << 17, dest[written_count..].len); // 128KiB
const block_size = block_header.block_size;
if (block_size_max < block_size) return error.BlockSizeOverMaximum;
switch (block_header.block_type) {
@ -805,6 +805,7 @@ pub fn decodeBlockReader(
try decode_state.prepare(block_reader, literals, sequences_header);
var bytes_written: usize = 0;
if (sequences_header.sequence_count > 0) {
if (sequence_buffer.len < block_reader_limited.bytes_left)
return error.SequenceBufferTooSmall;
@ -825,6 +826,7 @@ pub fn decodeBlockReader(
i == sequences_header.sequence_count - 1,
) catch return error.MalformedCompressedBlock;
sequence_size_limit -= decompressed_size;
bytes_written += decompressed_size;
}
}
@ -832,8 +834,10 @@ pub fn decodeBlockReader(
const len = literals.header.regenerated_size - decode_state.literal_written_count;
decode_state.decodeLiteralsRingBuffer(dest, len) catch
return error.MalformedCompressedBlock;
bytes_written += len;
}
if (bytes_written > block_size_max) return error.BlockSizeOverMaximum;
decode_state.literal_written_count = 0;
assert(block_reader.readByte() == error.EndOfStream);
},

4
lib/std/compress/zstandard/decompress.zig
View File

@ -236,6 +236,7 @@ pub fn decodeZstandardFrame(
src[consumed_count..],
&consumed_count,
if (frame_context.hasher_opt) |*hasher| hasher else null,
frame_context.block_size_max,
) catch |err| switch (err) {
error.DestTooSmall => return error.BadContentSize,
inline else => |e| return e,
@ -376,7 +377,6 @@ pub fn decodeZstandardFrameArrayList(
block_header = try block.decodeBlockHeaderSlice(src[consumed_count..]);
consumed_count += 3;
}) {
if (block_header.block_size > frame_context.block_size_max) return error.BlockSizeOverMaximum;
const written_size = try block.decodeBlockRingBuffer(
&ring_buffer,
src[consumed_count..],
@ -420,6 +420,7 @@ fn decodeFrameBlocks(
src: []const u8,
consumed_count: *usize,
hash: ?*std.hash.XxHash64,
block_size_max: usize,
) (error{ EndOfStream, DestTooSmall } || block.Error)!usize {
// These tables take 7680 bytes
var literal_fse_data: [types.compressed_block.table_size_max.literal]Table.Fse = undefined;
@ -441,6 +442,7 @@ fn decodeFrameBlocks(
block_header,
&decode_state,
&bytes_read,
block_size_max,
written_count,
);
if (hash) |hash_state| hash_state.update(dest[written_count .. written_count + written_size]);