Wind River Support Network

Description

In the Linux kernel, the following vulnerability has been resolved:net: let net.core.dev_weight always be non-zeroThe following problem was encountered during stability test:(NULL net_device): NAPI poll function process_backlog+0x0/0x530 \       returned 1, exceeding its budget of 0.------------ cut here ]------------list_add double add: new=ffff88905f746f48, prev=ffff88905f746f48, \  next=ffff88905f746e40.WARNING: CPU: 18 PID: 5462 at lib/list_debug.c:35 \      __list_add_valid_or_report+0xf3/0x130CPU: 18 UID: 0 PID: 5462 Comm: ping Kdump: loaded Not tainted 6.13.0-rc7+RIP: 0010:__list_add_valid_or_report+0xf3/0x130Call Trace:? __warn+0xcd/0x250? __list_add_valid_or_report+0xf3/0x130enqueue_to_backlog+0x923/0x1070netif_rx_internal+0x92/0x2b0__netif_rx+0x15/0x170loopback_xmit+0x2ef/0x450dev_hard_start_xmit+0x103/0x490__dev_queue_xmit+0xeac/0x1950ip_finish_output2+0x6cc/0x1620ip_output+0x161/0x270ip_push_pending_frames+0x155/0x1a0raw_sendmsg+0xe13/0x1550__sys_sendto+0x3bf/0x4e0__x64_sys_sendto+0xdc/0x1b0do_syscall_64+0x5b/0x170entry_SYSCALL_64_after_hwframe+0x76/0x7eThe reproduction command is as follows:  sysctl -w net.core.dev_weight=0  ping 127.0.0.1This is because when the napi's weight is set to 0, process_backlog() mayreturn 0 and clear the NAPI_STATE_SCHED bit of napi->state, causing thisnapi to be re-polled in net_rx_action() until __do_softirq() times out.Since the NAPI_STATE_SCHED bit has been cleared, napi_schedule_rps() canbe retriggered in enqueue_to_backlog(), causing this issue.Making the napi's weight always non-zero solves this problem.Triggering this issue requires system-wide admin (setting isnot namespaced).

CREATE(Triage):(User=admin) [CVE-2025-21806 (https://nvd.nist.gov/vuln/detail/CVE-2025-21806)