CVE-2026-98953: devlink: fix devlink_rel reference leak when notify work is pending
In the Linux kernel, the following vulnerability has been resolved:
devlink: fix devlinkrel reference leak when notify work is pending
devlinkrelnestedinnotifyworkschedule() takes a reference on the devlinkrel for the notify work and then queues the work, ignoring the return value of scheduledelayedwork(). If the work is already pending, nothing new is queued, the work runs only once and drops only one reference, so the extra one is leaked together with the devlinkrel and its index in devlinkrels.
This is easy to hit. devlregister() of a nested instance queues the work, and if the instance is unregistered before the work has run, devlinkrelput() queues it again while it is still pending. The work also keeps rescheduling itself for as long as the parent devlink lock cannot be taken, which widens the window. Registering and unregistering a nested devlink instance 100 times while holding the parent lock leaks all 100 devlinkrel objects.
The reschedule path in devlinkrelnestedinnotifywork() has the same problem: if the work was queued again while it was running, the reference it holds is never dropped.
Drop the reference in both places when the work was already pending. The pending work holds its own reference, so this can not be the last one.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1069.74~22.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1073.82~22.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fde-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1071.78~22.04.1 - Upgrade
Upgrade
ubuntu/linux-gcp-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1073.81~22.04.1 - Upgrade
Upgrade
ubuntu/linux-ibm-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1069.70~22.04.1 - Upgrade
Upgrade
ubuntu/linux-lowlatency-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-149.149.1~22.04.1 - Upgrade
Upgrade
ubuntu/linux-oracle-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1067.71~22.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-149.149~22.04.2 - Upgrade
Upgrade
ubuntu/linux-realtime-6.8to a version that resolves this vulnerability.Fixed in 6.8.1-1064.65~22.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.8.0-149.149 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.8.0-1069.74 - Upgrade
Upgrade
ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.18~24.04.1 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.8.0-1073.82 - Upgrade
Upgrade
ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1019.19~24.04.1 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 6.8.0-1073.81 - Upgrade
Upgrade
ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.19~24.04.1 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 6.8.0-1068.77 - Upgrade
Upgrade
ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 6.8.0-1053.57 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 6.8.0-1069.70 - Upgrade
Upgrade
ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-149.149.1 - Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 6.8.0-1067.70 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.8.0-1067.71 - Upgrade
Upgrade
ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1016.18~24.04.1 - Upgrade
Upgrade
ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 6.8.0-1068.72 - Upgrade
Upgrade
ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-43.43.1~24.04.2 - Upgrade
Upgrade
ubuntu/linux-vmwareto a version that resolves this vulnerability.Fixed in 6.8.0-1010.10 - Upgrade
Upgrade
ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 6.8.0-1036.41 - Upgrade
Upgrade
ubuntu/linux-raspi-realtimeto a version that resolves this vulnerability.Fixed in 6.8.0-2056.58 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.8.1-1064.65 - Upgrade
Upgrade
ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1069.74+fips1 - Upgrade
Upgrade
ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1073.82+fips1 - Upgrade
Upgrade
ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1073.81+fips1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.3.0-10.10 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.3.0-1004.4 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.3.0-1004.4 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.3.0-1004.5 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.3.0-1004.4 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.3.0-1004.4 - Upgrade
Upgrade
ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 7.3.0-1004.4 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.3.0-10.10.1 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.3.0-10.10.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-43.43 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1017.18 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1020.21 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1019.19 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1017.19 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1010.11 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1018.18 - Upgrade
Upgrade
ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1018.18 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-43.43.1 - Compensating control
In devlink_rel_nested_in_notify_work_schedule() and the reschedule path in devlink_rel_nested_in_notify_work(), drop the devlink_rel reference when the notify work is already pending, so a work item queued again does not leak an extra reference.
Event History
Frequently Asked Questions
What conditions trigger the leak?
The leak can occur when nested devlink notification work is already pending and another operation attempts to queue it. A documented trigger is registering a nested instance and unregistering it before its queued notification work runs; holding the parent devlink lock increases the window because the work reschedules while it cannot acquire that lock.
What is the practical impact of repeated triggering?
Each failed attempt to queue already-pending work can retain an extra devlink_rel reference, preventing the associated object and its devlink_rels index from being released. The description states that 100 nested-instance register/unregister cycles while holding the parent lock can leak all 100 devlink_rel objects.
How can I determine whether a system is affected?
Systems are exposed if they use nested devlink instances and can perform registration and unregistration while notification work is pending, particularly when the parent devlink lock is held. The supplied data does not provide affected kernel versions or a runtime detection method.