CVE-2026-53106

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

bpf: Do not allow deleting local storage in NMI

Currently, local storage may deadlock when deferring freeing selem or

local storage through kfree_rcu(), call_rcu() or call_rcu_tasks_trace()

in NMI or reentrant. Since deleting selem in NMI is an unlikely use

case, partially mitigate it by returning error when calling from

bpf_xxx_storage_delete() helpers in NMI. Note that, it is still possible

to deadlock through reentrant. A full mitigation requires returning

error when irqs_disabled() is true, which, however is too heavy-handed

for bpf_xxx_storage_delete().

The long-term solution requires _nolock versions of call_rcu. Another

possible solution is to defer the free through irq_work [0], but it

would grow the size of selem, which is non-ideal.

The check is only needed in bpf_selem_unlink(), which is used by helpers

and syscalls. bpf_selem_unlink_nofail() is fine as it is called during

map and owner tear down that ne

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References