kernel/tlsf: Add double-free detection in tlsf_freevec#777
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metaneutrons wants to merge 2 commits into
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kernel/tlsf: Add double-free detection in tlsf_freevec#777metaneutrons wants to merge 2 commits into
metaneutrons wants to merge 2 commits into
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Check if a block is already marked free before freeing it again. Double-frees corrupt the TLSF free-list and cause unpredictable crashes later. SMP-safe: check is after ObtainSemaphore (TOCTOU prevention). Uses local BOOL for semaphore-protection check to avoid duplicating the condition. Format string uses %lu with (unsigned long) cast for portability on 64-bit.
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Pull request overview
Adds a guard in the TLSF allocator’s tlsf_freevec() path to detect and short-circuit double-frees (after taking the optional pool semaphore), preventing free-list corruption in the kernel memory pool implementation.
Changes:
- Cache the pool’s semaphore-protection flag (
MEMF_SEM_PROTECTED) in a localBOOLto avoid repeated checks. - Add an early-return double-free check (
FREE_BLOCK(fb)) after semaphore acquisition, with a debug warning. - Use the cached semaphore flag for consistent release on all exit paths.
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Prevents TLSF free-list corruption from double-frees.