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CVE-2025-21858 is a use-after-free vulnerability in the Linux kernel's Geneve networking implementation. geneve_configure() can link a Geneve device into a device list belonging to a network namespace different from the device's own namespace. During teardown of the device's namespace, geneve_exit_batch_rtnl() unregisters the device, which is subsequently freed without removing its entry from the backend UDP socket namespace's Geneve list. Creating another Geneve device in that surviving namespace can cause geneve_find_dev() to access the freed object. KASAN detected a two-byte read from freed slab memory. The fix changes geneve_destroy_tunnels() to invoke geneve_dellink(), ensuring proper removal of the device's list entry.
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A use-after-free vulnerability in the Linux kernel's Geneve networking implementation. When a Geneve device and its backend UDP socket belong to different network namespaces, device teardown can leave a stale entry in the backend namespace's device list. Creating another Geneve device can then access freed memory. The reference assigns CVSS v3 severity 7.8 (High), with a local attack vector and low privileges required. The fix calls geneve_dellink() during tunnel destruction to remove the stale list entry.
A use-after-free vulnerability in the Linux kernel's Geneve networking implementation. When a Geneve device's network namespace is dismantled, the freed device can remain linked to the backend UDP socket namespace. Creating another Geneve device in that namespace can then access freed memory. The reference assigns CVSS v3 severity High (7.8), with a local attack vector and low privileges required. The fix calls geneve_dellink() during tunnel destruction; the prescribed remediation is to update Echo linux packages to version 6.1.133-1 or later.
A Linux kernel Geneve networking use-after-free vulnerability in geneve_find_dev().
A Linux-kernel Geneve networking use-after-free vulnerability in geneve_find_dev() that can lead to high-impact local compromise conditions. The affected Google COS sys-kernel/lakitu-kernel-6_1 package is remediated in version 18244.291.73 or later.
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