CVE-2026-31469

취약점 유형

In the Linux kernel, the following vulnerability has been resolved: virtio_net: Fix UAF on dst_ops when IFF_XMIT_DST_RELEASE is cleared and napi_tx is false A UAF issue occurs when the virtio_net driver is configured with napi_tx=N and the device's IFF_XMIT_DST_RELEASE flag is cleared (e.g., during the configuration of tc route filter rules). When IFF_XMIT_DST_RELEASE is removed from the net_device, the network stack expects the driver to hold the reference to skb->dst until the packet is fully transmitted and freed. In virtio_net with napi_tx=N, skbs may remain in the virtio transmit ring for an extended period. If the network namespace is destroyed while these skbs are still pending, the corresponding dst_ops structure has freed. When a subsequent packet is transmitted, free_old_xmit() is triggered to clean up old skbs. It then calls dst_release() on the skb associated with the stale dst_entry. Since the dst_ops (referenced by the dst_entry) has already been freed, a UAF kernel paging request occurs. fix it by adds skb_dst_drop(skb) in start_xmit to explicitly release the dst reference before the skb is queued in virtio_net. Call Trace: Unable to handle kernel paging request at v

영향받는 제품

• linux linux_kernel

참고 자료

• https://git.kernel.org/stable/c/63d45077b97bb0e0fe0c75931acbbca7a47af141
• https://git.kernel.org/stable/c/8a4790850e710fd6771e4d2112168ed1dd6c0e54
• https://git.kernel.org/stable/c/9a18629f2525781f0f3dda7be72b204e4cf77d08
• https://git.kernel.org/stable/c/ba8bda9a0896746053aa97ac6c3e08168729172c
• https://git.kernel.org/stable/c/be0e63f3b97bbaf453c542e8a15ba2a536e2ac01
• https://git.kernel.org/stable/c/c1ec36cb3768574b916f20d2d7415fd14fa1bf12