Hi Danijel,
Thanks for the patch.
On Fri, May 07, 2021 at 06:27:06PM +0800, Danijel Slivka wrote:
> This patch fixes segmentation fault during accessing already freed
> pci device resource files, as after freeing res_attr and res_attr_wc
> elements, in pci_remove_resource_files function, they are left as
> dangling pointers.
>
> Signed-off-by: Danijel Slivka <danijel.slivka@xxxxxxx>
> ---
> drivers/pci/pci-sysfs.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> index f8afd54ca3e1..bbdf6c57fcda 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -1130,12 +1130,14 @@ static void pci_remove_resource_files(struct pci_dev *pdev)
> if (res_attr) {
> sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
> kfree(res_attr);
> + pdev->res_attr[i] = NULL;
> }
>
> res_attr = pdev->res_attr_wc[i];
> if (res_attr) {
> sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
> kfree(res_attr);
> + pdev->res_attr_wc[i] = NULL;
If this patch fixes something, I would expect to see a test like this
somewhere:
if (pdev->res_attr[i])
pdev->res_attr[i]->size = 0;
But I don't see anything like that, so I can't figure out where we
actually use res_attr[i] or res_attr_wc[i], except in
pci_remove_resource_files() itself.
Did you actually see a segmentation fault? If so, where?
> }
> }
> }
> --
> 2.20.1
>
