In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: extend RCU protection in igmp6send() igmp6send() can be called without RTNL or RCU being held. Extend RCU protection so that we can safely fetch the net pointer and avoid a potential UAF. Note that we no longer can use sockallocsendskb() because ipv6.igmpsk uses GFPKERNEL allocations which can sleep. Instead use allocskb() and charge the net->ipv6.igmp_sk socket under RCU protection.