> From: Bjorn Helgaas <helg...@kernel.org> > Subject: Re: [PATCH v2] PCI: endpoint: Fix NULL pointer dereference for - > >get_features() > > On Fri, Dec 18, 2020 at 09:15:16PM +0530, Shradha Todi wrote: > > get_features ops of pci_epc_ops may return NULL, causing NULL pointer > > dereference in pci_epf_test_bind function. Let us add a check for > > pci_epc_feature pointer in pci_epf_test_bind before we access it to > > avoid any such NULL pointer dereference and return -ENOTSUPP in case > > pci_epc_feature is not found. > > Can you add a Fixes: tag to identify where this broke to help people decide > where to backport the fix? >
Thanks for the review. Sure we will add the Fixes tag and respin this patch. > > Reviewed-by: Pankaj Dubey <pankaj.du...@samsung.com> > > Signed-off-by: Sriram Dash <sriram.d...@samsung.com> > > Signed-off-by: Shradha Todi <shradh...@samsung.com> > > --- > > v2: > > rebase on v1 > > v1: > > https://protect2.fireeye.com/v1/url?k=6193fa90-3e08c3dd-619271df-0cc47 > > aa8f5ba-a79111ee2c1d1660&q=1&e=a9ee1ef7-2713-4099-8d06- > 738532d78b26&u= > > https%3A%2F%2Flore.kernel.org%2Fpatchwork%2Fpatch%2F1208269%2F > > > > drivers/pci/endpoint/functions/pci-epf-test.c | 13 ++++++++----- > > 1 file changed, 8 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c > > b/drivers/pci/endpoint/functions/pci-epf-test.c > > index 66723d5..f1842e6 100644 > > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > > @@ -835,13 +835,16 @@ static int pci_epf_test_bind(struct pci_epf *epf) > > return -EINVAL; > > > > epc_features = pci_epc_get_features(epc, epf->func_no); > > - if (epc_features) { > > - linkup_notifier = epc_features->linkup_notifier; > > - core_init_notifier = epc_features->core_init_notifier; > > - test_reg_bar = pci_epc_get_first_free_bar(epc_features); > > - pci_epf_configure_bar(epf, epc_features); > > + if (!epc_features) { > > + dev_err(&epf->dev, "epc_features not implemented\n"); > > + return -EOPNOTSUPP; > > } > > > > + linkup_notifier = epc_features->linkup_notifier; > > + core_init_notifier = epc_features->core_init_notifier; > > + test_reg_bar = pci_epc_get_first_free_bar(epc_features); > > + pci_epf_configure_bar(epf, epc_features); > > + > > epf_test->test_reg_bar = test_reg_bar; > > epf_test->epc_features = epc_features; > > > > -- > > 2.7.4 > >
