On Fri, Jun 14, 2019 at 04:56:32PM +0300, Andy Shevchenko wrote:
> On Fri, Jun 14, 2019 at 3:40 PM Young Xiao <92siuyang@xxxxxxxxx> wrote:
> >
> > There is otherwise a risk of a null pointer dereference.
>
> Had you analyze the code?
> How come that prevnode can become NULL?
Dropping this for now. Young, if there's a scenario where prevnode
can actually be NULL, please mention that in the changelog and repost
this.
> > Signed-off-by: Young Xiao <92siuyang@xxxxxxxxx>
> > ---
> > drivers/pci/hotplug/cpqphp_ctrl.c | 10 ++++++----
> > 1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/pci/hotplug/cpqphp_ctrl.c b/drivers/pci/hotplug/cpqphp_ctrl.c
> > index b7f4e1f..3c8399f 100644
> > --- a/drivers/pci/hotplug/cpqphp_ctrl.c
> > +++ b/drivers/pci/hotplug/cpqphp_ctrl.c
> > @@ -598,10 +598,11 @@ static struct pci_resource *get_io_resource(struct pci_resource **head, u32 size
> > *head = node->next;
> > } else {
> > prevnode = *head;
> > - while (prevnode->next != node)
> > + while (prevnode && prevnode->next != node)
> > prevnode = prevnode->next;
> >
> > - prevnode->next = node->next;
> > + if (prevnode)
> > + prevnode->next = node->next;
> > }
> > node->next = NULL;
> > break;
> > @@ -788,10 +789,11 @@ static struct pci_resource *get_resource(struct pci_resource **head, u32 size)
> > *head = node->next;
> > } else {
> > prevnode = *head;
> > - while (prevnode->next != node)
> > + while (prevnode && prevnode->next != node)
> > prevnode = prevnode->next;
> >
> > - prevnode->next = node->next;
> > + if (prevnode)
> > + prevnode->next = node->next;
> > }
> > node->next = NULL;
> > break;
> > --
> > 2.7.4
> >
>
>
> --
> With Best Regards,
> Andy Shevchenko
