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  1. Core Server
  2. SERVER-3633

three/four potential seg faults for non in mem yielding

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major - P3
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 2.0.0-rc1
    • Component/s: None
    • Labels:
      None
    • Operating System:
      ALL

      Description

      See QA-10

      For #1 right now I think we just touch the beginning of the record not the whole thing in all the cases where touch() gets called, but it is a latent issue. Same may be true for #2.

      1) Record::touch can read one byte past the end of a record if data == end, potentially this can cause a seg fault unless we always have some padding in extents which I haven't seen
      2) In update.cpp and clientcursor.cpp we use mmmutex to ensure a Record* doesn't get unmapped. However, this does not prevent the memory pointed at by the Record* from being changed. If the memory is changed so that the pointer no longer points to the beginning of a Record, it could interpret an invalid value as lengthWithHeaders and then read an invalid length when calling touch() causing a seg fault.
      3) In update.cpp, when we yield for an update by id, the 'nsdt' and 'd' pointers may be invalidated causing a seg fault.

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                • Created:
                  Updated:
                  Resolved: