[RP-PPPoE] Server dies under PADT flood

[Spinov Evgeniy]

Hi all, I have server with rp-pppoe-3.10-6 and pppd-2.4.5-15, meaning
the latest stable releases. Strange behavior of server was found while
one of the SOHO routers send PADT flood to server:  

Dec 26 10:03:03 nas5 pppoe-server[13954]: PADT for session 17 received
from 00:1A:70:9E:98:0D; should be from 00:C0:26:69:5F:7F
Dec 26 10:03:04 nas5 last message repeated 96 times
Dec 26 10:03:04 nas5 pppoe-server[13954]: PADT for session 1 received
from 00:1A:70:9E:98:0D; should be from 00:13:D4:8D:C5:58
Dec 26 10:03:04 nas5 pppoe-server[13954]: PADT for session 17 received
from 00:1A:70:9E:98:0D; should be from 00:C0:26:69:5F:7F
Dec 26 10:03:05 nas5 last message repeated 28 times
Dec 26 10:03:06 nas5 pppoe-server[13954]: PADT for session 1 received
from 00:1A:70:9E:98:0D; should be from 00:13:D4:8D:C5:58
Dec 26 10:03:06 nas5 last message repeated 46 times
Dec 26 10:03:06 nas5 pppoe-server[13954]: PADT for session 17 received
from 00:1A:70:9E:98:0D; should be from 00:C0:26:69:5F:7F
Dec 26 10:03:07 nas5 pppoe-server[13954]: PADT for session 1 received
from 00:1A:70:9E:98:0D; should be from 00:13:D4:8D:C5:58
Dec 26 10:03:07 nas5 last message repeated 14 times
Dec 26 10:03:07 nas5 pppoe-server[13954]: PADT for session 17 received
from 00:1A:70:9E:98:0D; should be from 00:C0:26:69:5F:7F
Dec 26 10:03:07 nas5 last message repeated 2 times
Dec 26 10:03:08 nas5 pppoe-server[13954]: PADT for session 1 received
from 00:1A:70:9E:98:0D; should be from 00:13:D4:8D:C5:58
Dec 26 10:03:08 nas5 pppoe-server[13954]: PADT for session 17 received
from 00:1A:70:9E:98:0D; should be from 00:C0:26:69:5F:7F
Dec 26 10:03:08 nas5 last message repeated 2 times

under heavy flood server dies. Time differs. May be 30 minutes, may be
10:
Dec 26 09:13:01 nas5 last message repeated 772 times 
Dec 26 09:13:01 nas5 pppoe-server[14903]: Terminating on signal 15 --
killing all PPPoE sessions

It's obvious, that flood could be filtered, but problem is that server
falling, without any reason. And who sends signal 15 in this case? 

Please advice.

Thanks.