On Thu, Nov 11, 2021 at 06:59:43PM +0100, Philippe Mathieu-Daudé wrote:
> On 11/11/21 16:33, Roman Kagan wrote:
> > Fix the (hypothetical) potential problem when the value parsed out of
> > the vhost module parameter in sysfs overflows the return value from
> > vhost_kernel_memslots_limit.
> >
> > Signed-off-by: Roman Kagan <[email protected]>
> > ---
> > hw/virtio/vhost-backend.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
> > index b65f8f7e97..44f7dbb243 100644
> > --- a/hw/virtio/vhost-backend.c
> > +++ b/hw/virtio/vhost-backend.c
> > @@ -58,7 +58,7 @@ static int vhost_kernel_memslots_limit(struct vhost_dev
> > *dev)
> > if (g_file_get_contents("/sys/module/vhost/parameters/max_mem_regions",
> > &s, NULL, NULL)) {
> > uint64_t val = g_ascii_strtoull(s, NULL, 10);
>
> Would using qemu_strtou64() simplify this?
I'm afraid not. None of the existing strtoXX converting functions has
the desired output range (0 < retval < INT_MAX), so the following
condition will remain necessary anyway; then it doesn't seem to matter
which particular parser is used to extract the value which is in the
range, so I left the one that was already there to reduce churn.
>
> > - if (!((val == G_MAXUINT64 || !val) && errno)) {
> > + if (val < INT_MAX && val > 0) {
> > g_free(s);
> > return val;
> > }
Thanks,
Roman.
