CVE-2022-48643

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nftables: fix nftcountersenabled underflow at nftables_addchain()

syzbot is reporting underflow of nftcountersenabled counter at nftablesaddchain() [1], for commit 43eb8949cfdffa76 ("netfilter: nftables: do not leave chain stats enabled on error") missed that nftableschaindestroy() after nftbasechaininit() in the error path of nftablesaddchain() decrements the counter because nftbasechaininit() makes nftisbasechain() return true by setting NFTCHAIN_BASE flag.

Increment the counter immediately after returning from nftbasechaininit().