On Mon, Sep 16, 2019 at 10:06:30AM +0800, Hillf Danton wrote:
>
> On Sun, 15 Sep 2019 09:34:37 -0700
> >
> > Kernel is 5.3-rc8 on x86_64.
> >
> > Loading and removing the pci-epf-test module causes a BUG.
> >
> >
> > [40928.435755] calling pci_epf_test_init+0x0/0x1000 [pci_epf_test] @ 12132
> > [40928.436717] initcall pci_epf_test_init+0x0/0x1000 [pci_epf_test] returned 0 after 891 usecs
> > [40936.996081] ==================================================================
> > [40936.996125] BUG: KASAN: use-after-free in pci_epf_remove_cfs+0x1ae/0x1f0
> > [40936.996153] Write of size 8 at addr ffff88810a22a068 by task rmmod/12139
>
> Fix fb0de5b8dcc6 and ef1433f717a2 if the current group::group_entry
> used by pci epf does not break how configfs uses it.
>
> --- a/drivers/pci/endpoint/pci-epf-core.c
> +++ b/drivers/pci/endpoint/pci-epf-core.c
> @@ -153,9 +153,11 @@ static void pci_epf_remove_cfs(struct pc
> return;
>
> mutex_lock(&pci_epf_mutex);
> - list_for_each_entry_safe(group, tmp, &driver->epf_group, group_entry)
> + list_for_each_entry_safe(group, tmp, &driver->epf_group,
> + group_entry) {
> + list_del_init(&group->group_entry);
> pci_ep_cfs_remove_epf_group(group);
> - list_del(&driver->epf_group);
> + }
> mutex_unlock(&pci_epf_mutex);
> }
Thank you Hillf. Kishon, can you confirm that's the proper fix for
this bug please ? I would like to turn this into a patch and merge
it in the upcoming merge window PR so it ought to be fairly quick,
please let me know asap.
Lorenzo
