[PATCH] PCI: quirks: Fix out-of-bounds MMIO read in nvme_disable_and_flr()

[Mohamad Raizudeen]

In nvme_disable_and_flr(), the PCI bar is mapped using
NVME_REG_CC + sizeof(cfg) which is (0x14 + 4 = 0x18 bytes)

However, the function later reads the controller status from
NVME_REG_CSTS - offset 0x1C, which is outside the mapped 0x18 byte
boundary and it can cause a page fault or kernel panic on architectures
that enforce strict MMIO boundaries.

Fix this by increasing the mapping size to include NVME_REG_CSTS.

Fixes: ffb0863426eb9 ("PCI: Disable Samsung SM961/PM961 NVMe before FLR")
Signed-off-by: Mohamad Raizudeen <raizudeen.kerneldev@xxxxxxxxx>
---
 drivers/pci/quirks.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index b09f27f7846f..ed03892cc960 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4090,7 +4090,7 @@ static int nvme_disable_and_flr(struct pci_dev *dev, bool probe)
 	if (probe)
 		return 0;
 
-	bar = pci_iomap(dev, 0, NVME_REG_CC + sizeof(cfg));
+	bar = pci_iomap(dev, 0, NVME_REG_CSTS + sizeof(cfg));
 	if (!bar)
 		return -ENOTTY;
 
-- 
2.53.0