Race condition in the sctp_icmp_proto_unreachable function in net/sctp/input.c in Linux kernel 2.6.11-rc2 through 2.6.33 allows remote attackers to cause a denial of service (panic) via an ICMP unreachable message to a socket that is already locked by a user, which causes the socket to be freed and triggers list corruption, related to the sctp_wait_for_connect function.