>From the Debian list: [Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index] Re: Apr 17 10:49:49 teks kernel: TCP: Treason uncloaked! Peer 210.135.175.47:43827/ ------------------------------------------------------------------------ -------- To: "Jason Lim" <maillist@xxxxxxxxxxxx>, <debian-isp@xxxxxxxxxxxxxxxx> Subject: Re: Apr 17 10:49:49 teks kernel: TCP: Treason uncloaked! Peer 210.135.175.47:43827/ From: Russell Coker <russell@xxxxxxxxxxxx> Date: Thu, 18 Apr 2002 04:33:36 +0200 In-reply-to: <045801c1e671$76cca2e0$360210ac@zentekgateway> Message-id: <20020418023337.6A14923FC@xxxxxxxxxxxxxxxxx> References: <045801c1e671$76cca2e0$360210ac@zentekgateway> Reply-to: Russell Coker <russell@xxxxxxxxxxxx> ------------------------------------------------------------------------ -------- On Thu, 18 Apr 2002 01:43, Jason Lim wrote: > Hi all, > > can anyone make sense of the following? > > Apr 17 10:49:49 teks kernel: TCP: Treason uncloaked! Peer > 210.135.175.47:43827/ > 80 shrinks window 2321430930:2321431630. Repaired. > > What is this "Treason uncloaked"? >From /usr/src/linux/net/ipv4/tcp_timer.c: if (tp->snd_wnd == 0 && !sk->dead && !((1<<sk->state)&(TCPF_SYN_SENT|TCPF_SYN_RECV))) { /* Receiver dastardly shrinks window. Our retransmits * become zero probes, but we should not timeout this * connection. If the socket is an orphan, time it out, * we cannot allow such beasts to hang infinitely. */ #ifdef TCP_DEBUG if (net_ratelimit()) printk(KERN_DEBUG "TCP: Treason uncloaked! Peer %u.%u.%u.%u:%u/%u shrinks window %u:%u. Repaired.\n", NIPQUAD(sk->daddr), htons(sk->dport), sk->num, tp->snd_una, tp->snd_nxt); #endif So it appears that someone is running some sort of "tar-pit" system that is designed to keep sockets in a bad state and run you out of kernel memory. I suspect that this ties in with the spam blocking things we recently discussed. Maybe you should tell your ISP that they are to blame for such actions being done to you and that they should "give you face" (I think that was the term you used) by closing their open relays. > I think the following is unrelated, but I also found a lot of them (50+) > in the logs: > > Apr 16 19:52:54 teks kernel: UDP: bad checksum. From 195.212.86.48:16384 > to xxx.194.146.xxx:33618 ulen 20 > Apr 16 19:53:00 teks kernel: UDP: bad checksum. From 195.212.86.48:16384 > to xxx.194.146.xxx:33561 ulen 20 UDP and TCP, no direct relation. But if someone's trying something nasty on one protocol they might be trying something nasty on another, the IPs are different, but faking the source of UDP is no great challenge. > About 6 hours later, the box crashed (not sure if it could be related to > the above attacks). Someone who's doing the tar-pit attack would probably like your box to crash, but I'd hope that Linux can withstand such things, and there is special-case code in there to deal with it. My guess is that your posting to the ide-arrays list about 3ware driver problems is a more likely explanation of the crash. -- If you send email to me or to a mailing list that I use which has >4 lines of legalistic junk at the end then you are specifically authorizing me to do whatever I wish with the message and all other messages from your domain, by posting the message you agree that your long legalistic sig is void. -- To UNSUBSCRIBE, email to debian-isp-request@xxxxxxxxxxxxxxxx with a subject of "unsubscribe". Trouble? Contact listmaster@xxxxxxxxxxxxxxxx ------------------------------------------------------------------------ -------- Reply to: debian-isp@xxxxxxxxxxxxxxxx Russell Coker (on-list) Russell Coker (off-list) ------------------------------------------------------------------------ -------- Follow-Ups: Re: Apr 17 10:49:49 teks kernel: TCP: Treason uncloaked! Peer 210.135.175.47:43827/ From: "Jason Lim" <maillist@xxxxxxxxxxxx> References: Apr 17 10:49:49 teks kernel: TCP: Treason uncloaked! Peer 210.135.175.47:43827/ From: "Jason Lim" <maillist@xxxxxxxxxxxx> Prev by Date: postfix with SASL on Debian? Next by Date: Re: Apr 17 10:49:49 teks kernel: TCP: Treason uncloaked! Peer 210.135.175.47:43827/ Previous by thread: Apr 17 10:49:49 teks kernel: TCP: Treason uncloaked! Peer 210.135.175.47:43827/ Next by thread: Re: Apr 17 10:49:49 teks kernel: TCP: Treason uncloaked! Peer 210.135.175.47:43827/ Index(es): Date Thread -----Original Message----- From: redhat-list-bounces@xxxxxxxxxx [mailto:redhat-list-bounces@xxxxxxxxxx] On Behalf Of Rushan Sobar Sent: Wednesday, August 03, 2005 3:35 PM To: 'General Red Hat Linux discussion list' Subject: kernel: TCP: Treason uncloaked! Hi, when I try to view my log file /var/log/messages I notice the following error Aug 2 11:19:44 mec kernel: TCP: Treason uncloaked! Peer 195.158.204.56:38087/80 shrinks window 2266547506:2266559926. Repaired. is it risky ? what kernel: TCP: Treason uncloaked means....... Regards Rushan -- This message has been scanned for viruses and dangerous content by MEC E-Mail Scanner, and is believed to be clean. -- www.mec.com.jo -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=subscribe https://www.redhat.com/mailman/listinfo/redhat-list -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list