The pipe_fcntl function in fs/pipe.c in the Linux kernel before 2.6.37 does not properly determine whether a file is a named pipe, which allows local users to cause a denial of service via an F_SETPIPE_SZ fcntl call.
http://openwall.com/lists/oss-security/2010/11/30/6
http://openwall.com/lists/oss-security/2010/11/30/9
http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.37