On Thu, Feb 06, 2020 at 03:17:04AM -0500, Michael S. Tsirkin wrote:
> On Wed, Jan 15, 2020 at 09:57:04PM -0500, Raphael Norwitz wrote:
> > The current vhost_user_set_mem_table_postcopy() implementation
> > populates each region of the VHOST_USER_SET_MEM_TABLE message without
> > first checking if there are more than VHOST_MEMORY_MAX_NREGIONS already
> > populated. This can cause memory corruption if too many regions are
> > added to the message during the postcopy step.
> >
> > This change moves an existing assert up such that attempting to
> > construct a VHOST_USER_SET_MEM_TABLE message with too many memory
> > regions will gracefully bring down qemu instead of corrupting memory.
> >
> > Signed-off-by: Raphael Norwitz <[email protected]>
> > Signed-off-by: Peter Turschmid <[email protected]>
>
>
> Could you pls add Fixes: and stable tags?
oh wait no, this is just a theoretical thing, right?
it doesn't actually trigger, it's just a cleanup.
no fixes/stable needed then, sorry
> > ---
> > hw/virtio/vhost-user.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> > index 2e81f55..cce851a 100644
> > --- a/hw/virtio/vhost-user.c
> > +++ b/hw/virtio/vhost-user.c
> > @@ -443,6 +443,7 @@ static int vhost_user_set_mem_table_postcopy(struct
> > vhost_dev *dev,
> > &offset);
> > fd = memory_region_get_fd(mr);
> > if (fd > 0) {
> > + assert(fd_num < VHOST_MEMORY_MAX_NREGIONS);
> > trace_vhost_user_set_mem_table_withfd(fd_num, mr->name,
> > reg->memory_size,
> > reg->guest_phys_addr,
> > @@ -455,7 +456,6 @@ static int vhost_user_set_mem_table_postcopy(struct
> > vhost_dev *dev,
> > msg.payload.memory.regions[fd_num].guest_phys_addr =
> > reg->guest_phys_addr;
> > msg.payload.memory.regions[fd_num].mmap_offset = offset;
> > - assert(fd_num < VHOST_MEMORY_MAX_NREGIONS);
> > fds[fd_num++] = fd;
> > } else {
> > u->region_rb_offset[i] = 0;
> > --
> > 1.8.3.1
