Linux Kernel IPv6 IGMPv6 Send RCU Protection Vulnerability

A vulnerability in the Linux kernel's IPv6 multicast handling has been addressed. The issue arose because the 'igmp6_send()' function could be called without the necessary RCU (Read-Copy-Update) or RTNL (Routing Netlink) protections, potentially leading to a use-after-free condition. The vulnerability has been mitigated by extending the RCU protection, allowing for safe retrieval of the net pointer while avoiding the risk of a use-after-free. Additionally, the method of socket allocation was changed to use 'alloc_skb()', as the previous method could not be used safely without risking sleep in the allocation process.

Impact

Exploitation of this vulnerability could lead to a use-after-free condition, potentially allowing for arbitrary code execution or memory corruption.