[PR #1815] fix(memory): Add null checks for unchecked memory allocations #2559

New Issue

claunia · 2026-01-29T17:22:46Z

claunia commented

2026-01-29 17:22:46 +00:00

Original Pull Request: https://github.com/CCExtractor/ccextractor/pull/1815

State: closed
Merged: Yes

Summary

Add proper null checks after malloc/calloc/realloc calls to prevent potential NULL pointer dereferences on out-of-memory conditions
Fix a variable shadowing bug in general_loop.c that caused a memory leak
Fix incorrect check ordering where null checks happened after pointer dereferences

Changes

File	Issue Fixed
`general_loop.c`	Add null checks for `line` and `parsebuf`; remove duplicate allocation that shadowed outer `bytes` variable (memory leak)
`ccx_encoders_webvtt.c`	Add null check for `color_events`/`font_events` calloc
`ccx_decoders_isdb.c`	Add null check for `text->buf` before dereference
`dvb_subtitle_decoder.c`	Move null check before `memset` (was crashing on OOM before reaching check)
`mp4.c`	Add null check for `dec_sub->data` before `memcpy`
`ccx_decoders_608.c`	Add null check for decoder context allocation
`ccx_decoders_xds.c`	Add null check for string buffer allocation
`asf_functions.c`	Add null check after struct initialization containing malloc
`ccx_dtvcc.c`	Move null check before dereferences (was checking after using pointer)
`lib_ccx.c`	Fix memset-before-check ordering; add checks for `pesheaderbuf` and DVB context

Test plan

Build completes successfully
Run test suite to verify no regressions

🤖 Generated with Claude Code

**Original Pull Request:** https://github.com/CCExtractor/ccextractor/pull/1815 **State:** closed **Merged:** Yes --- ## Summary - Add proper null checks after malloc/calloc/realloc calls to prevent potential NULL pointer dereferences on out-of-memory conditions - Fix a variable shadowing bug in `general_loop.c` that caused a memory leak - Fix incorrect check ordering where null checks happened after pointer dereferences ## Changes | File | Issue Fixed | |------|-------------| | `general_loop.c` | Add null checks for `line` and `parsebuf`; remove duplicate allocation that shadowed outer `bytes` variable (memory leak) | | `ccx_encoders_webvtt.c` | Add null check for `color_events`/`font_events` calloc | | `ccx_decoders_isdb.c` | Add null check for `text->buf` before dereference | | `dvb_subtitle_decoder.c` | Move null check before `memset` (was crashing on OOM before reaching check) | | `mp4.c` | Add null check for `dec_sub->data` before `memcpy` | | `ccx_decoders_608.c` | Add null check for decoder context allocation | | `ccx_decoders_xds.c` | Add null check for string buffer allocation | | `asf_functions.c` | Add null check after struct initialization containing malloc | | `ccx_dtvcc.c` | Move null check before dereferences (was checking *after* using pointer) | | `lib_ccx.c` | Fix memset-before-check ordering; add checks for `pesheaderbuf` and DVB context | ## Test plan - [x] Build completes successfully - [ ] Run test suite to verify no regressions 🤖 Generated with [Claude Code](https://claude.com/claude-code)

claunia added the pull-request label 2026-01-29 17:22:46 +00:00

claunia closed this issue

2026-01-29 17:22:46 +00:00

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Reference: starred/ccextractor#2559