kernel: netfilter: nftables out-of-bounds read in nf_osf_match_one()

A flaw was found in the Netfilter subsystem in the Linux kernel. The nfnlosfaddcallback function did not validate the user mode controlled optnum field. This flaw allows a local privileged CAPNETADMIN attacker to trigger an out-of-bounds read, leading to a crash or information disclosure...