جزئیات آسیب‌پذیری

In the Linux kernel, the following vulnerability has been resolved: xfrm: Fix dev use-after-free in xfrm async resumption xfrm async resumption hold skb->dev refcnt until after transport_finish. However, xfrm_rcv_cb may modify skb->dev to tunnel dev without taking device reference, such as vti_rcv_cb. The subsequent async resumption will decrement the tunnel device's reference count, which lead to uaf of tunnel dev and refcnt leak of orig dev as below: unregister_netdevice: waiting for vti1 to become free. Usage count = -2 Stash the original skb->dev to fix refcnt imbalance. The new skb->dev set by xfrm_rcv_cb can race with device teardown. Extend rcu protection over xfrm_rcv_cb and transport_finish to prevent races.

• https://git.kernel.org/stable/c/fed4d3195a31125566876952ce66113ec1eb9008
• https://git.kernel.org/stable/c/1acd93259b6be269e26be5d71c224bccd1f8352f
• https://git.kernel.org/stable/c/63a30015199912bd5055bead8001b1ae68a67cdb
• https://git.kernel.org/stable/c/8045c0df98d4f14c54e5cb875f1c9c0ce89fe4ff