Currently, the nvme_cmb_ops mr doesn't check the addr and size. This can lead an oob access issue. This is triggerable in the guest. Add check to avoid this issue.
Fixes CVE-2018-16847. Reported-by: Li Qiang <liq...@gmail.com> Reviewed-by: Paolo Bonzini <pbonz...@redhat.com> Signed-off-by: Li Qiang <liq...@gmail.com> --- hw/block/nvme.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/hw/block/nvme.c b/hw/block/nvme.c index fc7dacb..d097add 100644 --- a/hw/block/nvme.c +++ b/hw/block/nvme.c @@ -1175,6 +1175,10 @@ static void nvme_cmb_write(void *opaque, hwaddr addr, uint64_t data, unsigned size) { NvmeCtrl *n = (NvmeCtrl *)opaque; + + if (addr + size > NVME_CMBSZ_GETSIZE(n->bar.cmbsz)) { + return; + } memcpy(&n->cmbuf[addr], &data, size); } @@ -1183,6 +1187,9 @@ static uint64_t nvme_cmb_read(void *opaque, hwaddr addr, unsigned size) uint64_t val; NvmeCtrl *n = (NvmeCtrl *)opaque; + if (addr + size > NVME_CMBSZ_GETSIZE(n->bar.cmbsz)) { + return 0; + } memcpy(&val, &n->cmbuf[addr], size); return val; } -- 1.8.3.1