From: =?UTF-8?q?Rodr=C3=ADguez=20Barbarin=2C=20Jos=C3=A9=20Javier?=
 <JoseJavier.Rodriguez@duagon.com>
Date: Tue, 11 Apr 2023 10:33:28 +0200
Subject: [PATCH] mcb-pci: Reallocate memory region to avoid memory overlapping
References: bsc#1012628
Patch-mainline: 6.3.4
Git-commit: 9be24faadd085c284890c3afcec7a0184642315a

[ Upstream commit 9be24faadd085c284890c3afcec7a0184642315a ]

mcb-pci requests a fixed-size memory region to parse the chameleon
table, however, if the chameleon table is smaller that the allocated
region, it could overlap with the IP Cores' memory regions.

After parsing the chameleon table, drop/reallocate the memory region
with the actual chameleon table size.

Co-developed-by: Jorge Sanjuan Garcia <jorge.sanjuangarcia@duagon.com>
Signed-off-by: Jorge Sanjuan Garcia <jorge.sanjuangarcia@duagon.com>
Signed-off-by: Javier Rodriguez <josejavier.rodriguez@duagon.com>
Signed-off-by: Johannes Thumshirn <jth@kernel.org>
Link: https://lore.kernel.org/r/20230411083329.4506-3-jth@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/mcb/mcb-pci.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/mcb/mcb-pci.c b/drivers/mcb/mcb-pci.c
index dc88232d..53d9202f 100644
--- a/drivers/mcb/mcb-pci.c
+++ b/drivers/mcb/mcb-pci.c
@@ -31,7 +31,7 @@ static int mcb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct resource *res;
 	struct priv *priv;
-	int ret;
+	int ret, table_size;
 	unsigned long flags;
 
 	priv = devm_kzalloc(&pdev->dev, sizeof(struct priv), GFP_KERNEL);
@@ -90,7 +90,30 @@ static int mcb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (ret < 0)
 		goto out_mcb_bus;
 
-	dev_dbg(&pdev->dev, "Found %d cells\n", ret);
+	table_size = ret;
+
+	if (table_size < CHAM_HEADER_SIZE) {
+		/* Release the previous resources */
+		devm_iounmap(&pdev->dev, priv->base);
+		devm_release_mem_region(&pdev->dev, priv->mapbase, CHAM_HEADER_SIZE);
+
+		/* Then, allocate it again with the actual chameleon table size */
+		res = devm_request_mem_region(&pdev->dev, priv->mapbase,
+						table_size,
+						KBUILD_MODNAME);
+		if (!res) {
+			dev_err(&pdev->dev, "Failed to request PCI memory\n");
+			ret = -EBUSY;
+			goto out_mcb_bus;
+		}
+
+		priv->base = devm_ioremap(&pdev->dev, priv->mapbase, table_size);
+		if (!priv->base) {
+			dev_err(&pdev->dev, "Cannot ioremap\n");
+			ret = -ENOMEM;
+			goto out_mcb_bus;
+		}
+	}
 
 	mcb_bus_add_devices(priv->bus);
 
-- 
2.35.3