Tetsuo Handa
from-****@I-lov*****
Thu Jan 13 17:52:15 JST 2011
Jamie Nguyen wrote: > I would appreciate it if you could take a > look at the patch, as I was wondering if there are any serious > concerns about using both of these patches together? I am not sure if > they would do something unexpected and actually result in a huge > security flaw. I have no known issues with using both at the same time. I don't know how to use grsecurity. My worry is that grsecurity patch would let application repeat calling recv(MSG_PEEK) forever (i.e. CPU consumption loop in userland) due to try_again: skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), &peeked, &err); if (!skb) goto out; if (ccs_socket_post_recvmsg_permission(sk, skb, flags)) { err = -EAGAIN; /* Hope less harmful than -EPERM. */ goto out; } err = gr_search_udp_recvmsg(sk, skb); if (err) goto out_free; (...snipped...) out_free: skb_free_datagram_locked(sk, skb); out: return err; (in file net/ipv4/udp.c ) if the application did not close the socket upon error. (TOMOYO calls skb_kill_datagram() in ccs_socket_post_recvmsg_permission() upon error in order to avoid CPU consumption pitfall). Anyway, in the trunk/1.8.x/ccs-patch/patches/ directory, ccs-patch for 2.6.32.28+grsecurity and 2.6.36.3+grsecurity are ready. (revision 4358) Regards.