Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_queue: hold bridge skb->dev while queued br_pass_frame_up() rewrites skb->dev from the ingress port to the bridge master before queueing bridge LOCAL_IN packets. NFQUEUE only holds references on state.in/out and bridge physdevs, so a queued bridge packet can retain a freed bridge master in skb->dev until reinjection. When the verdict is reinjected later, br_netif_receive_skb() re-enters the receive path with skb->dev still pointing at the freed bridge master, triggering a use-after-free. Store skb->dev in the queue entry, hold a reference on it for the queue lifetime, and use the saved device when dropping queued packets during NETDEV_DOWN handling.

References 8

• git.kernel.org https://git.kernel.org/stable/c/15d464265120ab9818bd673af301deee09bedab2
• git.kernel.org https://git.kernel.org/stable/c/19924bdd8a45ebc72a7b84c57fd63057d1dc75ac
• git.kernel.org https://git.kernel.org/stable/c/1e5e20031c5eee8d2e490a90ff4d6a2feecfc3be
• git.kernel.org https://git.kernel.org/stable/c/3823c27099cfe2482299065814adbaa771be9644
• git.kernel.org https://git.kernel.org/stable/c/3fb0f5c0f64162a8c3f25616a4f1e340b921737f
• git.kernel.org https://git.kernel.org/stable/c/950d809f154dca04e5fbe5d3c8b9c5e44769cd57
• git.kernel.org https://git.kernel.org/stable/c/a698ac8ab2561cf575d2d9f34095032651dd952e
• git.kernel.org https://git.kernel.org/stable/c/e196115ec330a18de415bdb9f5071aa9f08e53ce

Remediation