CVE-2026-98035

/// Technical description

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

bpf: Cancel special fields when recycling rhtab elements

rhtab_map_update_existing() and rhtab_delete_elem() call

bpf_obj_free_fields() when replacing or deleting a value. These map

operations can run from BPF programs in NMI context, where releasing a

referenced kptr or another complex field is not generally safe.

Array and hash maps avoid that problem by cancelling only the asynchronous

fields which can be stopped safely in the caller context. Other ownership

state remains attached to the allocation until its memory allocator

destructor performs the final cleanup.

Use bpf_obj_cancel_fields() for the corresponding rhtab paths as well. This

cancels timers, workqueues, and task work while allowing rhtab_mem_dtor() to

release referenced kptrs when the allocation is eventually destroyed.

[ kkd: Rebased, used direct helper calls, and rewrote the commit log ]

/// 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