CVE-2026-98035

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 ]