On 28 May 2019, at 4:31, Stoiko Ivanov wrote:
Hello,
with a recent update to the ruleset, we're encountering certain mails,
which cause the rule-evaluation to use 100% cpu.
The effect was reproduced with Proxmox Mailgateway 5.2 (running
Spamassassin 3.4.2 ) and Ubuntu 19.04 (also running Spamassassin
3.4.2)
I have reproduced this on CentOS 7 with the stock Perl 5.16 and manually
installed 5.18 and 5.28 builds. SA hangs while evaluating the rule and
eventually times out.
On stock fully-updated CentOS 6 the hang is worse: apparently perl gets
stuck inside a syscall and it ignores the alarm signal for the timeout,
hanging the process indefinitely.
Further muddying the issue, on Mac OS X 10.6.8 with Perl 5.26 (MacPorts
local build) the hang simply does not happen.
After some debugging the issue was narrowed down to the rule
__STYLE_GIBBERISH_1 .
Confirmed: switching to the simpler version of that rule which is used
for older versions of Perl eliminates the hang. I suspect that the
ultimate fix may be to just back off to the version of the rule that is
already used for older Perl.
I have to admit that I don't entirely understand the complex version
that is causing the hang. However, I have experimented with limiting
some of the ranges in it with no success.
--
Bill Cole
b...@scconsult.com or billc...@apache.org
(AKA @grumpybozo and many *@billmail.scconsult.com addresses)
