CVE-2026-43083

CRITICAL

net: ioam6: fix OOB and missing lock

Title source: cna
STIX 2.1

Description

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.

Scores

CVSS v3 9.1
EPSS 0.0005
EPSS Percentile 16.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Details

Status published
Products (8)
Linux/Linux < 5.17
Linux/Linux 5.17
Linux/Linux 6.18.24 - 6.18.*
Linux/Linux 6.19.14 - 6.19.*
Linux/Linux 7.0
Linux/Linux b63c5478e9cb1d1504eb02d9dac827ad24612b32 - 6d1d9ed9b409e0662241e3d245d574a18f643494
Linux/Linux b63c5478e9cb1d1504eb02d9dac827ad24612b32 - 95a1334748c95dd15546056280ade0c4b8dd7b78
Linux/Linux b63c5478e9cb1d1504eb02d9dac827ad24612b32 - b30b1675aa2bcf0491fd3830b051df4e08a7c8ca
Published May 06, 2026
Tracked Since May 06, 2026