[PR #1840] fix(memory): Fix uninitialized memory and memory leaks found by Valgrind #2603

New Issue

claunia · 2026-01-29T17:23:01Z

claunia commented

2026-01-29 17:23:01 +00:00

Original Pull Request: https://github.com/CCExtractor/ccextractor/pull/1840

State: closed
Merged: Yes

Summary

Comprehensive memory fixes found via Valgrind testing. This PR eliminates memory leaks, use-after-free bugs, and uninitialized memory issues across both C and Rust code.

Commits

Fix uninitialized memory and memory leaks - Use calloc() instead of malloc() in demuxer/decoder init
Fix use-after-free and memory leaks in Rust FFI - Prevent dangling pointers when copy_from_rust() is called multiple times
Fix major memory leaks in Rust FFI demuxer/decoder - Fix 55MB-331MB leaks in Dtvcc encoder allocation
Fix use-after-free in Teletext - Properly null out dec_ctx->private_data after Teletext context is freed
Fix 608 decoder memory leak - Free DVB bitmap data in dinit_cc_decode()
Fix XDS encoder/decoder leaks - Free xds_str when skipping invalid timestamps
Fix XDS rcwt_loop leak - Add cleanup for --in=bin and --in=raw formats
Fix Rust CI - Update test code for Drop compatibility + formatting

Valgrind Test Results (245 tests)

Test Range	Perfect	Memory Leaks	Timeouts
Tests 1-99	TBD	TBD	TBD
Tests 100-150	33	0	17
Tests 151-200	48	0	0
Tests 200-245	37	0	4

All tested ranges show 0 bytes definitely lost.

Key Fixes Verified

Test 114: 0 bytes (was 100 bytes) - XDS encoder leak
Tests 217/218: 0 bytes (was 880 bytes) - rcwt_loop XDS leak
Tests 24, 26-28: 0 bytes (was 55MB-331MB) - Rust FFI leaks

Technical Details

C Code Fixes

ccx_demuxer.c: calloc() in init_demuxer()
lib_ccx.c: calloc() in init_decoder_setting()
telxcc.c: calloc() in telxcc_init()
general_loop.c: Initialize variables, add rcwt_loop cleanup
ccx_decoders_common.c: Free DVB bitmap and XDS strings in cleanup
ccx_encoders_common.c: Free XDS strings on invalid timestamp skip

Rust FFI Fixes

utils.rs: Add replace_rust_c_string(), free_rust_c_string_array()
common.rs: Only set inputfile/enc_cfg on first call to prevent leaks
demuxer.rs: Direct C struct manipulation in ccxr_demuxer_close()
decoder/mod.rs: Only allocate encoder when ctx.encoder is null
common_types.rs: Add Drop for CcxDemuxer to free FFI allocations

Known Pre-existing Issues

Test 19: 5536 bytes leaked from teletext with --datapid (complex interaction, pre-existing)
Uninitialized value warnings in some tests (not memory leaks)

Test plan

Build successfully on Linux
Cargo fmt passes
Cargo test passes (269 tests)
Valgrind tests 100-245: 0 memory leaks
Basic functionality verified with sample files

🤖 Generated with Claude Code

**Original Pull Request:** https://github.com/CCExtractor/ccextractor/pull/1840 **State:** closed **Merged:** Yes --- ## Summary Comprehensive memory fixes found via Valgrind testing. This PR eliminates memory leaks, use-after-free bugs, and uninitialized memory issues across both C and Rust code. ## Commits 1. **Fix uninitialized memory and memory leaks** - Use `calloc()` instead of `malloc()` in demuxer/decoder init 2. **Fix use-after-free and memory leaks in Rust FFI** - Prevent dangling pointers when `copy_from_rust()` is called multiple times 3. **Fix major memory leaks in Rust FFI demuxer/decoder** - Fix 55MB-331MB leaks in Dtvcc encoder allocation 4. **Fix use-after-free in Teletext** - Properly null out `dec_ctx->private_data` after Teletext context is freed 5. **Fix 608 decoder memory leak** - Free DVB bitmap data in `dinit_cc_decode()` 6. **Fix XDS encoder/decoder leaks** - Free `xds_str` when skipping invalid timestamps 7. **Fix XDS rcwt_loop leak** - Add cleanup for `--in=bin` and `--in=raw` formats 8. **Fix Rust CI** - Update test code for Drop compatibility + formatting ## Valgrind Test Results (245 tests) | Test Range | Perfect | Memory Leaks | Timeouts | |------------|---------|--------------|----------| | Tests 1-99 | TBD | TBD | TBD | | Tests 100-150 | 33 | **0** | 17 | | Tests 151-200 | 48 | **0** | 0 | | Tests 200-245 | 37 | **0** | 4 | **All tested ranges show 0 bytes definitely lost.** ### Key Fixes Verified - Test 114: 0 bytes (was 100 bytes) - XDS encoder leak - Tests 217/218: 0 bytes (was 880 bytes) - rcwt_loop XDS leak - Tests 24, 26-28: 0 bytes (was 55MB-331MB) - Rust FFI leaks ## Technical Details ### C Code Fixes - `ccx_demuxer.c`: `calloc()` in `init_demuxer()` - `lib_ccx.c`: `calloc()` in `init_decoder_setting()` - `telxcc.c`: `calloc()` in `telxcc_init()` - `general_loop.c`: Initialize variables, add rcwt_loop cleanup - `ccx_decoders_common.c`: Free DVB bitmap and XDS strings in cleanup - `ccx_encoders_common.c`: Free XDS strings on invalid timestamp skip ### Rust FFI Fixes - `utils.rs`: Add `replace_rust_c_string()`, `free_rust_c_string_array()` - `common.rs`: Only set inputfile/enc_cfg on first call to prevent leaks - `demuxer.rs`: Direct C struct manipulation in `ccxr_demuxer_close()` - `decoder/mod.rs`: Only allocate encoder when `ctx.encoder` is null - `common_types.rs`: Add `Drop` for `CcxDemuxer` to free FFI allocations ## Known Pre-existing Issues - **Test 19**: 5536 bytes leaked from teletext with `--datapid` (complex interaction, pre-existing) - Uninitialized value warnings in some tests (not memory leaks) ## Test plan - [x] Build successfully on Linux - [x] Cargo fmt passes - [x] Cargo test passes (269 tests) - [x] Valgrind tests 100-245: 0 memory leaks - [x] Basic functionality verified with sample files 🤖 Generated with [Claude Code](https://claude.com/claude-code)

claunia added the pull-request label 2026-01-29 17:23:01 +00:00

claunia closed this issue

2026-01-29 17:23:01 +00:00

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Reference: starred/ccextractor#2603