From: Ard Biesheuvel ardb@kernel.org
[ Upstream commit d09ddd8190fbdc07696bf34b548ae15aa1816714 ]
When resizing a BAR, pci_reassign_bridge_resources() is invoked to bring the bridge windows of parent bridges in line with the new BAR assignment.
This assumes the device whose BAR is being resized lives on a subordinate bus, but this is not necessarily the case. A device may live on the root bus, in which case dev->bus->self is NULL, and passing a NULL pci_dev pointer to pci_reassign_bridge_resources() will cause it to crash.
So let's make the call to pci_reassign_bridge_resources() conditional on whether dev->bus->self is non-NULL in the first place.
Fixes: 8bb705e3e79d84e7 ("PCI: Add pci_resize_resource() for resizing BARs") Link: https://lore.kernel.org/r/20200421162256.26887-1-ardb@kernel.org Signed-off-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Bjorn Helgaas bhelgaas@google.com Reviewed-by: Christian König christian.koenig@amd.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/pci/setup-res.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c index d8ca40a97693..d21fa04fa44d 100644 --- a/drivers/pci/setup-res.c +++ b/drivers/pci/setup-res.c @@ -439,10 +439,11 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size) res->end = res->start + pci_rebar_size_to_bytes(size) - 1;
/* Check if the new config works by trying to assign everything. */ - ret = pci_reassign_bridge_resources(dev->bus->self, res->flags); - if (ret) - goto error_resize; - + if (dev->bus->self) { + ret = pci_reassign_bridge_resources(dev->bus->self, res->flags); + if (ret) + goto error_resize; + } return 0;
error_resize: