CVE-2026-72255

Status: UPDATED  |  Advisory ID: CVE-2026-72255

Key Details

Affected Products, Subsystems & Sectors

What to Know

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

netfilter: nf_queue: pin bridge device while NFQUEUE holds fake dst

The br_netfilter fake rtable is embedded in struct net_bridge and is

attached to bridged packets with skb_dst_set_noref(). If such a packet is

queued to NFQUEUE, __nf_queue() upgrades that fake dst with

skb_dst_force().

At that point the queued skb can hold a real dst reference after bridge

teardown has started. The problem is not that every bridged packet needs

its own dst reference. The problem is that NFQUEUE can keep the bridge

private fake dst alive after unregister begins.

Fix this by keeping the bridge fake dst model unchanged and pinning the

bridge master device only while the packet sits in NFQUEUE. Record the

bridge device in nf_queue_entry when the queued skb carries a bridge fake

dst, take a device reference for the queue lifetime, and drop it when the

queue entry is freed.

Also make sure queued entries are reaped when that bridge device goes

down, and drop the redundant nf_bridge_info_exists() test from the fake

dst detection.

This keeps netdev_priv(br->dev) alive until verdict completion, so the

embedded fake rtable and its metrics backing storage cannot be freed out

from under dst_release(). It also avoids the constant refcount bump and

avoids using ipv4-specific dst helpers for IPv6 bridge traffic. (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References