Bug#821848: perl: Regexp-matching "hangs" indefinitely on illegal input using binmode :utf8 using 100%CPU

[Dominic Hargreaves]

On Tue, Apr 19, 2016 at 11:49:02PM +0300, Alexandros Kosiaris wrote:
> Package: perl
> Version: 5.20.2-3+deb8u4
> Severity: normal
> Tags: upstream patch
> 
> Dear Maintainer,
> 
> There is a bug in Perl 5.8.9 (at least) that causes regular
> expressions an malformed UTF8 inputs to go into a forever loop and
> consume 100% CPU. Upstream's tracker url is
> https://rt.perl.org/Public/Bug/Display.html?id=123562. Patch is at
> http://perl5.git.perl.org/perl.git/commitdiff/22b433eff9a1ffa2454e18405a56650f07b385b5
> and attached is a version rebased for Debian Jessie. I have not
> confirmed it, but based on the versions numbers I believe Stretch and Sid are also affected.

Thanks for the report. This was fixed in perl 5.22.1, which is now
in sid and stretch.

We might be able to fix this in stable; we'll see how that goes.

Cheers,
Dominic.