[PATCH] PCI: Follow-up fix for BAR hardening

[PATCH] PCI: Follow-up fix for BAR hardening

[Philipp Stanner]

Fixes a bug where variables were used before being initialized.

To be squashed into commit "PCI: Check BAR index for validity"

Signed-off-by: Philipp Stanner <phasta@kernel.org>
---
Fix for this already applied patch:
https://lore.kernel.org/all/20250304143112.104190-2-phasta@kernel.org/
---
 drivers/pci/iomap.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/iomap.c b/drivers/pci/iomap.c
index 0cab82cbcc99..fe706ed946df 100644
--- a/drivers/pci/iomap.c
+++ b/drivers/pci/iomap.c
@@ -40,13 +40,14 @@ void __iomem *pci_iomap_range(struct pci_dev *dev,
 
 	if (!pci_bar_index_is_valid(bar))
 		return NULL;
-	if (len <= offset || !start)
-		return NULL;
 
 	start = pci_resource_start(dev, bar);
 	len = pci_resource_len(dev, bar);
 	flags = pci_resource_flags(dev, bar);
 
+	if (len <= offset || !start)
+		return NULL;
+
 	len -= offset;
 	start += offset;
 	if (maxlen && len > maxlen)
@@ -90,13 +91,13 @@ void __iomem *pci_iomap_wc_range(struct pci_dev *dev,
 
 	if (!pci_bar_index_is_valid(bar))
 		return NULL;
-	if (len <= offset || !start)
-		return NULL;
 
 	start = pci_resource_start(dev, bar);
 	len = pci_resource_len(dev, bar);
 	flags = pci_resource_flags(dev, bar);
 
+	if (len <= offset || !start)
+		return NULL;
 	if (flags & IORESOURCE_IO)
 		return NULL;
 
-- 
2.48.1

Re: [PATCH] PCI: Follow-up fix for BAR hardening

[Krzysztof Wilczyński]

Hello,

> Fixes a bug where variables were used before being initialized.
> 
> To be squashed into commit "PCI: Check BAR index for validity"

Squashed against the existing code on the branch.  Have a look:

  https://web.git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git/commit/?h=devres&id=ba10e5011d05f20bd71d3f765fd3a77f7577ff34

Thank you!

	Krzysztof