CVE-2026-53270: ipvs: clear the svc scheduler ptr early on edit
In the Linux kernel, the following vulnerability has been resolved:
ipvs: clear the svc scheduler ptr early on edit
ipvseditservice() while unbinding the old scheduler clears the svc->scheduler ptr after the scheduler module initiates RCU callbacks. This can cause packets to use the old scheduler at the time when svc->scheddata is already freed after RCU grace period.
Fix it by clearing the ptr early in ipvsunbindscheduler(), before the doneservice method schedules any RCU callbacks.
Also, if the new scheduler fails to initialize when replacing the old scheduler, try to restore the old scheduler while still returning the error code.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.6.143.1-1 - Compensating control
If replacing the old scheduler and the new scheduler fails to initialize, fix it by clearing the ptr early in ip_vs_unbind_scheduler() (as described: “ip_vs_edit_service() while unbinding the old scheduler clears …”).
- Operational
When unbinding/editing the scheduler, ensure svc->scheduler ptr is cleared early so done_service won’t schedule RCU callbacks after svc->sched_data has been freed; this prevents packets from using the old scheduler after the RCU grace period (per the description: “ipvs: clear the svc scheduler ptr early on edit”).
Event History
Frequently Asked Questions
What is the severity of CVE-2026-53270?
CVE-2026-53270 has a risk rating of 50.
How do I fix CVE-2026-53270?
To fix CVE-2026-53270, update your Linux kernel to the latest patched version that addresses this vulnerability.
What systems are affected by CVE-2026-53270?
CVE-2026-53270 affects systems running the Linux kernel with the IPVS feature enabled.
What type of vulnerability is CVE-2026-53270?
CVE-2026-53270 is a security vulnerability related to improper handling of service scheduler pointers in the Linux kernel.
What potential impact does CVE-2026-53270 have?
CVE-2026-53270 can cause packets to use an old scheduler, potentially leading to unexpected network behavior.