Re: [tor-relays] TCP SACK PANIC type kernel vulnerabilities: logging some packets

Hi,

On 6/24/19 2:13 PM, tor@t-3.net wrote:

As of last week there wasn't a new kernel out for our relay's distro

switch to Gentoo Linux :-)

-A INPUT -p tcp --tcp-flags SYN SYN -m tcpmss --mss 1:500 -j LOG --log-prefix "TCP_SACK_PANIC: " -A INPUT -p tcp --tcp-flags SYN SYN -m tcpmss --mss 1:500 -j DROP

Interesting - never thoughtm that iptables is able to do that - the doubled SYN is needed, right?

Over the weekend we logged hits to this rule. I checked a few of the source hosts, and they were not relays at least as they are listed in https://check.torproject.org/cgi-bin/TorBulkExitList.py?ip=1.1.1.1 .

Whilst I gave up loging IPs at all - why didn't you checked non-exit relays?