The change log to Convert::UUlib 1.50 shows:

  Revision history for Perl extension Convert::UUlib.

  1.5  Sat Jul 11 03:56:06 CEST 2015
  - fix a heap overflow (testcase by Krzysztof Wojtaƛ).
  - on systems that support it (posix + mmap + map_anonymous),
    allocate all dynamic areas via mmap and put four guard
    pages around them, to catch similar heap overflows
    safely in the future.
  - find a safer way to pass in CC/CFLAGS to uulib.
  - added stability canary support.


The extra protection (guard pages) is probably what is
causing your crashes: previously some heap overflow could
cause corruption and havoc without necessarily being noticed,
bringing down a process. If I understand the changelog
correctly, the new guard pages make it possible to detect
some runaway memory access in uulib and terminate the process
if this occurs, instead of letting a corruption spread.

This is a good step in guarding against security exploits:
better crash than let a leak be exploitable. Unfortunately
the violation cannot be contained, which affects apparent
stability.

  Mark

Reply via email to