Xen backends of para-virtualized devices can live in dom0 kernel, dom0 user land, or in a driver domain. This means that a backend might reside in a less trusted environment than the Xen core components, so a backend should not be able to do harm to a Xen guest (it can still mess up I/O data, but it shouldn't be able to e.g. crash a guest by other means or cause a privilege escalation in the guest). Unfortunately blkfront in the Linux kernel is fully trusting its backend. This series is fixing blkfront in this regard. It was discussed to handle this as a security problem, but the topic was discussed in public before, so it isn't a real secret. Changes in V2: - put blkfront patches into own series - some minor comments addressed Juergen Gross (3): xen/blkfront: read response from backend only once xen/blkfront: don't take local copy of a request from the ring page xen/blkfront: don't trust the backend response data blindly drivers/block/xen-blkfront.c | 122 +++++++++++++++++++++++------------ 1 file changed, 80 insertions(+), 42 deletions(-) -- 2.26.2
