full-disclosure - Re: Linux kernel scm

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20041223155439.15412.qmail@paddy.troja.mff.cuni.cz>
From: peak at argo.troja.mff.cuni.cz (Pavel Kankovsky)
Subject: Re: Linux kernel scm_send local DoS

On Tue, 14 Dec 2004, Paul Starzetz wrote:

> The Linux kernel provides a powerful socket API  to  user  applications.
> Among other functions sockets provide an universal way for IPC and user-
> kernel communication. The socket layer uses several  logical  sublayers.
> One  of  the  layers,  so called auxiliary message layer (or scm layer),
> augments the socket API by  an  universal  user-kernel  message  passing
> capability (see recvfrom(2) for more details on auxiliary messages).

More nasties might be lurking nearby (at least in 2.4):

- additional, almost identical, copies of cmsg parsing code appear in
  ip_cmsg_send() (net/ipv4/ip_sockglue.c) and datagram_send_ctl()
  (net/ipv6/datagram.c)

- sys_sendmsg() (net/socket.c) is willing to allocate almost arbitrary 
  large blocks of kernel memory


--Pavel Kankovsky aka Peak  [ Boycott Microsoft--http://www.vcnet.com/bms ]
"Resistance is futile. Open your source code and prepare for assimilation."