kernel: netfilter: bridge: confirm multicast packets before passing them up the stack

A security vulnerability was identified in the Linux kernel's netfilter subsystem, specifically affecting the handling of multicast and broadcast packets on network bridges. The issue arises from a race condition in the connection tracking conntrack module when processing cloned socket buffers sk...

CVE-2024-27415

CVE-2024-27415 affects Linux kernel netfilter/bridge. Root cause: nf_confirm and conntrack race when multicast/broadcast frames clone, causing a shared nf_conn entry to be referenced twice before confirmation. Result: a multicast flow can lead to a clone skb’s nfct being unconfirmed and race agai...