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fix(sys): Bounds-check event record readers - #744
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The Read* and Consume* helpers on EventRecord validated offsets with `offset > BufferLen`, which still allows reads that start inside the payload but run past its end, and which is satisfied by `offset == BufferLen`. Several helpers also did arithmetic on uint16 values that silently wraps. Because the payload is a raw pointer handed over by ETW, every one of these turned into an out-of-bounds read of adjacent memory (information leak or access violation) or a panic that takes the process down.
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What is the purpose of this PR / why it is needed?
The
Read*andConsume*helpers onEventRecordvalidated offsets withoffset > BufferLen, which still allows reads that start inside the payload but run past its end, and which is satisfied byoffset == BufferLen. Several helpers also did arithmetic on uint16 values that silently wrap. Because the payload is a raw pointer handed over by ETW, every one of these turned into an out-of-bounds read of adjacent memory (information leak or access violation) or a panic that takes the process down.What type of change does this PR introduce?
/kind bug-fix (non-breaking change which fixes an issue)
/kind improvement
Any specific area of the project related to this PR?
/area instrumentation
Special notes for the reviewer
Does this PR introduce a user-facing change?