virtio-net: correctly copy vnet header when flushing TX
When HASH_REPORT is negotiated, the guest_hdr_len might be larger than
the size of the mergeable rx buffer header. Using
virtio_net_hdr_mrg_rxbuf during the header swap might lead a stack
overflow in this case. Fixing this by using virtio_net_hdr_v1_hash
instead.
Reported-by: Xiao Lei <leixiao.nop@zju.edu.cn> Cc: Yuri Benditovich <yuri.benditovich@daynix.com> Cc: qemu-stable@nongnu.org Cc: Mauro Matteo Cascella <mcascell@redhat.com> Fixes: CVE-2023-6693 Fixes: e22f0603fb2f ("virtio-net: reference implementation of hash report") Reviewed-by: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: Jason Wang <jasowang@redhat.com>