CVE-2026-43083

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

net: ioam6: fix OOB and missing lock

When trace->type.bit6 is set:

if (trace->type.bit6) {

...

queue = skb_get_tx_queue(dev, skb);

qdisc = rcu_dereference(queue->qdisc);

This code can lead to an out-of-bounds access of the dev->_tx[] array

when is_input is true. In such a case, the packet is on the RX path and

skb->queue_mapping contains the RX queue index of the ingress device. If

the ingress device has more RX queues than the egress device (dev) has

TX queues, skb_get_queue_mapping(skb) will exceed dev->num_tx_queues.

Add a check to avoid this situation since skb_get_tx_queue() does not

clamp the index. This issue has also revealed that per queue visibility

cannot be accurate and will be replaced later as a new feature.

While at it, add missing lock around qdisc_qstats_qlen_backlog(). The

function __ioam6_fill_trace_data() is called from both softirq and

process contexts, hence the use of spin_lock_bh() here.