Fix readSuspensionHandlers null deref on invalid tag index#575
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titzer merged 3 commits intotitzer:masterfrom Mar 4, 2026
Merged
Fix readSuspensionHandlers null deref on invalid tag index#575titzer merged 3 commits intotitzer:masterfrom
titzer merged 3 commits intotitzer:masterfrom
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readSuspensionHandlers calls readTagRef().tag_index without checking for null. When the tag index is invalid, readTagRef() returns null, causing a null dereference. Store the readTagRef() result and return early if null.
titzer
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Mar 3, 2026
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Thanks, can you please add a regression test for this case?
CodeValidator must check err.ok() after readSuspensionHandlers() in RESUME/RESUME_THROW/RESUME_THROW_REF handlers to avoid processing partially-filled handler arrays when tag index validation fails. Add regression test with RESUME instruction referencing invalid tag index 99 in suspension handler.
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Summary
readSuspensionHandlerscallsreadTagRef().tag_indexwithout checking for null. When the tag index is invalid,readTagRef()returns null, causing a null dereference.Details
WasmParser.v3:384— store thereadTagRef()result in a local, check for null before accessing.tag_index, and return early if null.