UBUNTU-CVE-2026-68126: Use After Free
In the Linux kernel, the following vulnerability has been resolved: mac802154: hold an interface reference across the scan worker mac802154scanworker() captures the scanning sub-interface under RCU and then keeps dereferencing sdata->dev after rcureadunlock() and outside the rtnl -- in the failure traces, in mac802154transmitbeaconreq() (skb->dev = sdata->dev), and in the endscan cleanup. Nothing keeps that netdev alive across the worker iteration. A concurrent DELINTERFACE or PHY removal can unregister the interface once the worker drops the rtnl between its two drvsetchannel() sections. unregisternetdevice() frees the netdev asynchronously from netdevruntodo() with the rtnl already dropped, so neither holding the rtnl nor the per-PHY IEEE802154ISSCANNING flag prevents a stale worker iteration from dereferencing the freed netdev -- a KASAN slab-use-after-free, reachable by racing TRIGGERSCAN against DELINTERFACE (both CAPNETADMIN). Pin the netdev with netdevhold() while the RCU read lock is still held, and release it at every worker exit.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.8.0-147.147 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.8.0-1067.70 - Upgrade
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ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79 - Upgrade
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ubuntu/linux-azure-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17~24.04.1 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 6.8.0-1069.76 - Upgrade
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ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1016.16~24.04.1 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79 - Upgrade
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ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 6.8.0-1066.74 - Upgrade
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ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 6.8.0-1052.56 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38~24.04.4 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 6.8.0-1067.68 - Upgrade
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ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-147.147.1 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.8.0-1064.67 - Upgrade
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ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1~24.04.1 - Upgrade
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ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 6.8.0-1033.38 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.8.1-1062.63 - Upgrade
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ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1067.70+fips1 - Upgrade
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ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79+fips1 - Upgrade
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ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-147.147+fips1 - Upgrade
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ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79+fips1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-38.38 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1016.16 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1008.9 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Compensating control
In mac802154_scan_worker(), pin the scanning netdev with netdev_hold() while the RCU read lock is still held, and release the reference at every worker exit, including failure paths and end_scan cleanup.
Event History
Frequently Asked Questions
Who can trigger this issue?
An attacker needs CAP_NET_ADMIN privileges. The documented trigger races TRIGGER_SCAN against DEL_INTERFACE; PHY removal can also create the unsafe lifetime condition.
Are systems affected by ordinary wireless traffic alone?
The provided information describes a local race involving administrative interface and scan operations, not exploitation through ordinary wireless traffic. Both TRIGGER_SCAN and DEL_INTERFACE require CAP_NET_ADMIN.
What can be done if an update cannot be applied immediately?
Restrict CAP_NET_ADMIN to trusted users and workloads, and avoid concurrent scan triggering with interface deletion or PHY removal. This reduces exposure to the documented race condition.
How can administrators identify a possible occurrence?
The failure is described as a KASAN slab-use-after-free involving mac802154 scan work, including dereferences in mac802154_transmit_beacon_req() or end_scan cleanup. Review kernel diagnostics for use-after-free reports during concurrent scan and interface-removal activity.