kernel: ipv6: skb is unexpectedly freed

Use-after-free vulnerability in net/ipv4/tcpinput.c in the Linux kernel 2.6 before 2.6.20, when IPV6RECVPKTINFO is set on a listening socket, allows remote attackers to cause a denial of service kernel panic via a SYN packet while the socket is in a listening TCPLISTEN state, which is not properl...