On Fri, Jun 14, 2019 at 3:40 PM Young Xiao <[email protected]> wrote: > > There is otherwise a risk of a null pointer dereference.
Had you analyze the code? How come that prevnode can become NULL? > Signed-off-by: Young Xiao <[email protected]> > --- > 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
