The Linux kernel's ntb_netdev_rx_handler function previously handed received packets to the network stack before allocating a replacement buffer. If the allocation failed, no new buffer was reposted, reducing the RX queue depth and eventually stalling packet reception while the interface remained up. The fix changes the logic to allocate the replacement buffer before handing off the packet. If allocation fails, the packet is dropped and the same skb is reposted, preserving the RX queue depth and preventing reception stalls.

If memory allocation fails during packet reception, the RX queue depth decreases without replenishment, causing the network interface to stall reception of packets despite remaining operational. This can lead to denial of service conditions on affected systems until memory becomes available again.

A fix has been implemented in the Linux kernel to address this issue by changing the buffer allocation order in ntb_netdev_rx_handler. Users should apply the official kernel update that includes this fix. Patch status is not explicitly confirmed in the provided data; check the Linux kernel vendor advisory or source repository for the specific patch and update instructions.