Just to clarify: does the problem happens when you have the MARK rule
above in a user-defined chain that has more then one jump leading to
it or does it also happen in other cases?
=> I triggered the bug with a real world example:
- first add a rule with a MARK target using a set mark with the first/sign
bit set to one. This target is coded with this mark put at the same
place than the verdict field of standard targets. (note this should
be triggered by a lot of targets but I got it with MARK)
- try to add another rule (with -A or -I but this works too with restore,
the idea is to get a replace ioctl with an illegal value in a verdict
position).
- if you are (un?)lucky you get the ELOOP error.
PS: I really need a bug-ticket-etc number because some business is implied
PPS: here I've cut & paste the config I used to track the bug:#
....
:MARKOUT1 - [0:0]
-A PREROUTING -d 10.0.200.2/32 -p tcp -m tcp --dport 5001 -j MARKOUT1 -A MARKOUT1 -j MARK --set-xmark 0x80000001/0xffffffff -A MARKOUT1 -j CONNMARK --save-mark --nfmask 0x3fffffff --ctmask 0x3fffffff -A MARKOUT1 -j ACCEPT
I got the bug with the UDP counterpart:
iptables -t mangle -A PREROUTING -d 10.0.200.2/32 -p udp --dport 5001 \
-j MARKOUT1