authorgravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2025-07-28 15:18:43-07:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2025-07-31 22:10:11-07:00
log7bf91d705c241609eb9d459d7556b2fc2afee7a1
treedcf40b088adcf115ed967da774bfe2776ac39a2c
parent73e5594c78a66fb943638d99f8540bec0b5ed839

fix bit read not at eof

1 files changed, 5 insertions(+), 5 deletions(-)

lib/std/compress/flate/Decompress.zig+5-5
......@@ -245,7 +245,8 @@ fn readInner(d: *Decompress, w: *Writer, limit: std.Io.Limit) (Error || Reader.S
245245 var dec_lens: [286 + 30]u4 = @splat(0);
246246 var pos: usize = 0;
247247 while (pos < hlit + hdist) {
248 const sym = try cl_dec.find(@bitReverse(try d.peekBits(u7)));
248 const peeked = @bitReverse(try d.peekBits(u7));
249 const sym = try cl_dec.find(peeked);
249250 try d.tossBits(sym.code_bits);
250251 pos += try d.dynamicCodeLength(sym.symbol, &dec_lens, pos);
251252 }
......@@ -377,7 +378,7 @@ fn takeBits(d: *Decompress, comptime T: type) !T {
377378 error.EndOfStream => return takeBitsEnding(d, T),
378379 };
379380 const needed_bits = @bitSizeOf(T) - remaining_bits;
380 const u: U = @intCast((next_bits << needed_bits) | (next_int & ((@as(usize, 1) << needed_bits) - 1)));
381 const u: U = @intCast(((next_int & ((@as(usize, 1) << needed_bits) - 1)) << remaining_bits) | next_bits);
381382 d.next_bits = next_int >> needed_bits;
382383 d.remaining_bits = @intCast(@bitSizeOf(usize) - @as(usize, needed_bits));
383384 return switch (@typeInfo(T)) {
......@@ -434,7 +435,7 @@ fn peekBits(d: *Decompress, comptime T: type) !T {
434435 error.EndOfStream => return peekBitsEnding(d, T),
435436 };
436437 const needed_bits = @bitSizeOf(T) - remaining_bits;
437 const u: U = @intCast((next_bits << needed_bits) | (next_int & ((@as(usize, 1) << needed_bits) - 1)));
438 const u: U = @intCast(((next_int & ((@as(usize, 1) << needed_bits) - 1)) << remaining_bits) | next_bits);
438439 return switch (@typeInfo(T)) {
439440 .int => u,
440441 .@"enum" => @enumFromInt(u),
......@@ -983,11 +984,10 @@ test "fuzzing tests" {
983984 .{ .input = "puff27", .err = error.InvalidDynamicBlockHeader },
984985 };
985986
986 inline for (cases, 0..) |c, case_no| {
987 inline for (cases) |c| {
987988 var in: Reader = .fixed(@embedFile("testdata/fuzz/" ++ c.input ++ ".input"));
988989 var aw: Writer.Allocating = .init(testing.allocator);
989990 defer aw.deinit();
990 errdefer std.debug.print("test case failed {}\n", .{case_no});
991991
992992 var decompress: Decompress = .init(&in, .raw, &.{});
993993 const r = &decompress.reader;