tree 6eb76b4632b7c131e0fbb52d8ce7cccf658b6bfa
parent 82c558761d0fa42dc954d62812b9e4b4a94f64bd
author Damien Miller <djm@mindrot.org> 1308781803 +1000
committer Damien Miller <djm@mindrot.org> 1308781803 +1000

   - djm@cvs.openbsd.org 2011/06/22 21:57:01
     [servconf.c servconf.h sshd.c sshd_config.5 sandbox-rlimit.c]
     [sandbox-systrace.c sandbox.h configure.ac Makefile.in]
     introduce sandboxing of the pre-auth privsep child using systrace(4).

     This introduces a new "UsePrivilegeSeparation=sandbox" option for
     sshd_config that applies mandatory restrictions on the syscalls the
     privsep child can perform. This prevents a compromised privsep child
     from being used to attack other hosts (by opening sockets and proxying)
     or probing local kernel attack surface.

     The sandbox is implemented using systrace(4) in unsupervised "fast-path"
     mode, where a list of permitted syscalls is supplied. Any syscall not
     on the list results in SIGKILL being sent to the privsep child. Note
     that this requires a kernel with the new SYSTR_POLICY_KILL option.

     UsePrivilegeSeparation=sandbox will become the default in the future
     so please start testing it now.

     feedback dtucker@; ok markus@