parsers/c-based: add nesting depth limit to prevent stack overflow#4440
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pengfeixx wants to merge 1 commit into
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parsers/c-based: add nesting depth limit to prevent stack overflow#4440pengfeixx wants to merge 1 commit into
pengfeixx wants to merge 1 commit into
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Limit the maximum nesting depth in createTags() to MAX_NEST_LEVEL (1024) to prevent stack overflow when processing deeply nested braces (e.g. crafted Java source files with thousands of nested blocks). When the limit is exceeded, the parser skips to the matching brace instead of recursing, preventing unbounded stack growth that leads to SIGSEGV. Fixes: universal-ctags#4439
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Thank you. I'm thinking about fixing the original issue via #4387. |
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Summary
MAX_NEST_LEVEL = 1024) to the C-based parser to prevent stack overflow when processing deeply nested bracesskipToMatch("{}")) instead of recursingChanges
parsers/c-based.c#define MAX_NEST_LEVEL 1024; added depth check increateTags()before recursivenest()callRoot Cause
The
createTags()→nest()→createTags()recursive call chain has no depth bound. When processing a file with deeply nested braces (e.g. 54000 levels), this causes uncontrolled stack growth leading to SIGSEGV.Test Plan
poc-java-stack-overflow-54000.java) attached to the issue — should no longer crashgcc -std=c99 -fsyntax-only— no compilation errorsFixes #4439