CVE-2022-50000: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-50000 is a vulnerability in the Linux kernel's netfilter flowtable functionality, disclosed in June 2025. The issue affects the flow table cleanup process in the Linux kernel's netfilter subsystem, where flows can become stuck during cleanup due to pending work (NVD, Wiz).

The vulnerability occurs in a specific sequence during flow table cleanup where: 1) gcstep work is stopped to disable further stats/del requests, 2) flow table entries are set to teardown state, 3) gcstep queues HW del work for entries, 4) system waits for del work to finish, 5) gc_step runs again to delete entries, and 6) flow table is freed. The issue manifests when a flow table entry has pending HW stats or HW add work, causing step 3 to skip queueing HW del work, which can lead to use-after-free conditions (NVD).

The vulnerability can result in stuck flows during cleanup operations and potential use-after-free conditions in the kernel. This is evidenced by KASAN reports showing write operations to freed memory addresses, which could lead to system instability or potential security implications (Wiz).

The fix involves modifying the cleanup sequence to: 1) flush pending work, 2) set teardown flags for all flows in the flowtable, 3) force a garbage collector run to queue work for removing flows from hardware, 4) flush the new pending work, and 5) force another garbage collector run to remove entries from the software flowtable (Wiz).