In our recent article: Local Denial-of-Service using setsockopt(), we discussed the ability of a local users to cause a Denial of Service attack on a BSD system. An unofficial patch has been released, which allows administrators to set the limit on the number of resource that can be allocated by sockets, effectively preventing the DoS attack.
The name "sbsize" (RLIMIT_SBSIZE) is used (by the patch) to define the number of resource allowed to be allocated by sockets.
Here's what happens with the a limit set to 2000000:
{"/home/green"}$ ulimit -b 2000000 ; ulimit -a | grep sbsize sbsize(bytes) 2000000
{"/home/green"}$ ./testsockbuf
socketpair: No buffer space available
14 sockets had been allocated
(NOTE: testsockbug is an exploit code similar to what we have published)
