CVE-2026-31407

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

netfilter: conntrack: add missing netlink policy validations

Hyunwoo Kim reports out-of-bounds access in sctp and ctnetlink.

These attributes are used by the kernel without any validation.

Extend the netlink policies accordingly.

Quoting the reporter:

nlattr_to_sctp() assigns the user-supplied CTA_PROTOINFO_SCTP_STATE

value directly to ct->proto.sctp.state without checking that it is

within the valid range. [..]

and: ... with exp->dir = 100, the access at

ct->master->tuplehash[100] reads 5600 bytes past the start of a

320-byte nf_conn object, causing a slab-out-of-bounds read confirmed by

UBSAN.