CVE-2026-90113netdevsim: update queue NAPI association on queue reset

Official description

In the Linux kernel, the following vulnerability has been resolved: netdevsim: update queue NAPI association on queue reset In netdevsim, receive queues (struct nsim_rq) embed their own struct napi_struct. When queue reset is performed (e.g. via queue_reset debugfs), nsim_queue_start() swaps in a newly allocated struct nsim_rq, and nsim_queue_mem_free() later deletes and frees the old one. However, nsim_queue_start() failed to update the queue-to-NAPI mapping via netif_queue_set_napi(). As a result, dev->_rx[idx].napi continued to point to the old NAPI struct. After the old queue was freed, a subsequent queue dump via Netlink (NETDEV_CMD_QUEUE_GET) triggered a KASAN slab-use-after-free read in nla_put_napi_id() when accessing rxq->napi->napi_id. Fix this by calling netif_queue_set_napi() in nsim_queue_start() to associate the new NAPI with the RX queue, and clear the association with netif_queue_set_napi(..., NULL) in nsim_del_napi() during teardown.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/b8f32b0804b4bf0cba0ee0a093e3fd74f11d7166
• https://git.kernel.org/stable/c/db038ac4dca0fa626199e9c297eddd8362be0550
• https://git.kernel.org/stable/c/07e98a4d5e9c292eae97c9cc5ab0937384e48492