kernel: Use-after-free in nft_verdict_dump due to a race between set GC and transaction

A use-after-free flaw was found in the Linux kernel’s nftables sub-component due to a race problem between the set GC and transaction in the Linux Kernel. This flaw allows a local attacker to crash the system due to a missing call to nftsetelemmarkbusy, causing double deactivation of the element...