Quoting Tetsuo Handa (penguin-kernel@xxxxxxxxxxxxxxxxxxx): > Samir Bellabes wrote: > > I'm currently testing security_sock_rcv_skb() hook - which is inside > > sk_filter() - to get skbuffs when then are arriving, and so trying to > > push the buffer to userspace. In case this is not userfull, userspace > > is able to use the NFQUEUE of netfilter to get skbuff, and deal > > with incoming datas. > > Pushing buffer to userspace and wait for userspace's decision will sleep. > sk_filter() which calls security_sock_rcv_skb() hook is called from > (e.g.) tcp_v6_do_rcv() and comment of tcp_v6_do_rcv() says that > "The socket must have it's spinlock held when we get here." > Also, comment of rxrpc_queue_rcv_skb() says that > "the caller must hold a lock on call->lock". > I think it is not permitted to do sleeping operation inside > security_sock_rcv_skb(). Ah, there it is, thanks for finding a specific instance. I'd looked a bit yesterday but couldn't find it. Tetsuo, would you mind sending a patch to add a note to security.h's comment for socket_sock_rcv_skb: that it can't sleep? It also used to be the case for security_task_free() which presumably would be hooked by the ssyscall or whatever was mentioned. thanks, -serge -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
