In the Linux kernel, the following vulnerability has been resolved:
ipv6: mcast: add RCU protection to mld_newpack()
mld_newpack() can be called without RTNL or RCU being held.
Note that we no longer can use sock_alloc_send_skb() because ipv6.igmp_sk uses GFP_KERNEL allocations which can sleep.
Instead use alloc_skb() and charge the net->ipv6.igmp_sk socket under RCU protection.