From f6f89f3b99f57f5c53e698b09e05fa3c9c3cb6ec Mon Sep 17 00:00:00 2001
From: Dominik Loidolt <dominik.loidolt@univie.ac.at>
Date: Tue, 17 Sep 2024 10:50:44 +0200
Subject: [PATCH] Fix: Corrected size calculation when `dst` is NULL in
`compress_chunk()`
When `dst` is NULL, the returned size was sometimes incorrect by a few
bytes compared to when the `dst` buffer is set. This issue has now been
fixed.
---
lib/icu_compress/cmp_icu.c | 10 +++++-----
test/fuzz/fuzz_compression.c | 7 +++++++
test/test_common/chunk_round_trip.c | 15 +++++++++++++++
3 files changed, 27 insertions(+), 5 deletions(-)
diff --git a/lib/icu_compress/cmp_icu.c b/lib/icu_compress/cmp_icu.c
index c8a7430..45791ee 100644
--- a/lib/icu_compress/cmp_icu.c
+++ b/lib/icu_compress/cmp_icu.c
@@ -1755,23 +1755,23 @@ static uint32_t cmp_collection(const uint8_t *col,
cfg->updated_model_buf = updated_model + COLLECTION_HDR_SIZE;
/* is enough capacity in the dst buffer to store the data uncompressed */
- if ((!dst || dst_capacity >= dst_size + col_data_length) &&
+ if ((dst == NULL || dst_capacity >= dst_size + col_data_length) &&
cfg->cmp_mode != CMP_MODE_RAW) {
/* we set the compressed buffer size to the data size -1 to provoke
* a CMP_ERROR_SMALL_BUF_ error if the data are not compressible
*/
cfg->stream_size = dst_size + col_data_length - 1;
- dst_size_bits = compress_data_internal(cfg, dst_size<<3);
+ dst_size_bits = compress_data_internal(cfg, dst_size << 3);
if (cmp_get_error_code(dst_size_bits) == CMP_ERROR_SMALL_BUF_ ||
- (!dst && cmp_bit_to_byte(dst_size_bits)-dst_size > col_data_length)) { /* if dst == NULL compress_data_internal will not return a CMP_ERROR_SMALL_BUF */
+ (!dst && dst_size_bits > cmp_stream_size_to_bits(cfg->stream_size))) { /* if dst == NULL compress_data_internal will not return a CMP_ERROR_SMALL_BUF */
/* can not compress the data with the given parameters;
* put them uncompressed (raw) into the dst buffer */
enum cmp_mode cmp_mode_cpy = cfg->cmp_mode;
cfg->stream_size = dst_size + col_data_length;
cfg->cmp_mode = CMP_MODE_RAW;
- dst_size_bits = compress_data_internal(cfg, dst_size<<3);
+ dst_size_bits = compress_data_internal(cfg, dst_size << 3);
cfg->cmp_mode = cmp_mode_cpy;
/* updated model is in this case a copy of the data to compress */
if (model_mode_is_used(cfg->cmp_mode) && cfg->updated_model_buf)
@@ -1779,7 +1779,7 @@ static uint32_t cmp_collection(const uint8_t *col,
}
} else {
cfg->stream_size = dst_capacity;
- dst_size_bits = compress_data_internal(cfg, dst_size<<3);
+ dst_size_bits = compress_data_internal(cfg, dst_size << 3);
}
FORWARD_IF_ERROR(dst_size_bits, "compression failed");
diff --git a/test/fuzz/fuzz_compression.c b/test/fuzz/fuzz_compression.c
index 8be34ff..bde54b3 100644
--- a/test/fuzz/fuzz_compression.c
+++ b/test/fuzz/fuzz_compression.c
@@ -133,6 +133,13 @@ int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
default:
FUZZ_ASSERT(0);
}
+ if (!cmp_is_error(return_value) && model != up_model){
+ uint32_t return_value2;
+
+ return_value2 = compress_chunk(src, (uint32_t)size, model, up_model,
+ NULL, cmp_data_capacity, cmp_par_ptr);
+ FUZZ_ASSERT(return_value == return_value2);
+ }
free(cmp_data);
free(up_model);
diff --git a/test/test_common/chunk_round_trip.c b/test/test_common/chunk_round_trip.c
index b51bc48..f23fcea 100644
--- a/test/test_common/chunk_round_trip.c
+++ b/test/test_common/chunk_round_trip.c
@@ -89,6 +89,21 @@ uint32_t chunk_round_trip(const void *chunk, uint32_t chunk_size,
cmp_size = compress_chunk(chunk, chunk_size, chunk_model, updated_chunk_model,
dst, dst_capacity, cmp_par);
+ if (!cmp_is_error(cmp_size)) { /* secound run wich dst = NULL */
+ uint32_t cmp_size2;
+ /* reset model if in-place update was used */
+ if (chunk_model && updated_chunk_model == chunk_model) {
+ memcpy(updated_chunk_model, model_cpy, chunk_size);
+ }
+ cmp_size2 = compress_chunk(chunk, chunk_size, chunk_model, updated_chunk_model,
+ NULL, dst_capacity, cmp_par);
+ if (cmp_get_error_code(cmp_size) == CMP_ERROR_SMALL_BUF_) {
+ TEST_ASSERT(!cmp_is_error(cmp_size));
+ } else {
+ TEST_ASSERT(cmp_size == cmp_size2);
+ }
+ }
+
/* decompress the data if the compression was successful */
if (!cmp_is_error(cmp_size) && dst) {
--
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