[2.6.25-rc1] Locks in udp_recvmsg()?

Hello.

I found that udp_recvmsg() in net/ipv4/udp.c for 2.6.25-rc1 calls
lock_sock() only when it releases the datagram (i.e. out_free: and csum_copy_err:).
Is it correct to call __skb_recv_datagram() without calling lock_sock()
when it acquires the datagram (i.e. try_again:)?

Regards.