A flaw was found in the Linux kernel's netback driver which can cause the driver to use excessive amounts of memory. Incoming data packets for a guest in the Linux kernel's netback driver are buffered until the guest is ready to process them. There are some measures taken to avoid piling up too much data, but those can be bypassed by the guest. There is a timeout on how long the client side of an interface can stop consuming new packets before it is assumed to have stalled. The timeout may never trigger if the guest manages to have only one free slot in its RX queue ring page and the next package would require more than one free slot, which may be the case when using GSO, XDP, or software hashing.
A flaw was found in the Linux kernel's netback driver which can cause the driver to use excessive amounts of memory. Incoming data packets for a guest in the Linux kernel's netback driver are buffered until the guest is ready to process them. There are some measures taken to avoid piling up too much data, but those can be bypassed by the guest. There is a timeout on how long the client side of an interface can stop consuming new packets before it is assumed to have stalled. The timeout may never trigger if the guest manages to have only one free slot in its RX queue ring page and the next package would require more than one free slot, which may be the case when using GSO, XDP, or software hashing.