fix: TOCTOU race condition in vTaskListTasks()#1431
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AniruddhaKanhere merged 1 commit intoJun 19, 2026
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Read uxCurrentNumberOfTasks once into uxArraySize and use that local variable for both the size check and pvPortMalloc() call. The previous code read the volatile variable twice, allowing a task to be created between the reads, resulting in an undersized allocation that could cause a buffer overflow in uxTaskGetSystemState().
AniruddhaKanhere
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Jun 19, 2026
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Thank you for your contribution @srpatcha!
This looks good to me. Approved!
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #1431 +/- ##
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- Coverage 91.37% 91.28% -0.10%
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Files 6 6
Lines 3259 3269 +10
Branches 902 905 +3
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+ Hits 2978 2984 +6
- Misses 132 135 +3
- Partials 149 150 +1
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gmtt
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Jun 19, 2026
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Description
vTaskListTasks() and vTaskList() read the volatile uxCurrentNumberOfTasks twice: once for the zero-check and once for pvPortMalloc(). If a task is created between the two reads, the allocated buffer is undersized, causing a potential buffer overflow in uxTaskGetSystemState().
Fix
Use the local variable uxArraySize (already assigned from uxCurrentNumberOfTasks) for the pvPortMalloc() call instead of re-reading the volatile.
Changes
Split from #1409 per reviewer request to separate the bug fix from .editorconfig changes.