Bug 2570095 (CVE-2026-99286)
| Summary: | CVE-2026-99286 kernel: kernel: xen-netback: Denial of Service via race condition during connection cleanup | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | Keywords: | Security |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
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| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel's xen-netback driver. During a virtual network connection failure, the driver deallocates queue resources before resetting the active queue count. A local user or guest domain could exploit this race condition by requesting network statistics during cleanup, causing the system to access freed memory. This issue primarily leads to a denial of service (DoS) due to a kernel crash.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
In the Linux kernel, the following vulnerability has been resolved: xen-netback: Fix XenBus connection failure cleanup xenvif_get_stats and xenvif_get_ethtool_stats capture vif->num_queues under rcu_read_lock. We need to unpublish vif->num_queues before synchronize_net to ensure that readers that come afterwards will not read a non-zero vif->num_queues and attempt to access invalid queues. This is the same cleanup algorithm as used in backend_disconnect and added in commit b17075d5c198 ("xen-netback: fix race condition on XenBus disconnect"). This is XSA-531