[PATCH AUTOSEL 6.12 074/107] fsl/fman: Validate cell-index value obtained from Device Tree

[Sasha Levin]

From: Aleksandr Mishin <amishin@xxxxxxxxxx>

[ Upstream commit bd50c4125c98bd1a86f8e514872159700a9c678c ]

Cell-index value is obtained from Device Tree and then used to calculate
the index for accessing arrays port_mfl[], mac_mfl[] and intr_mng[].
In case of broken DT due to any error cell-index can contain any value
and it is possible to go beyond the array boundaries which can lead
at least to memory corruption.

Validate cell-index value obtained from Device Tree.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Reviewed-by: Sean Anderson <sean.anderson@xxxxxxxx>
Signed-off-by: Aleksandr Mishin <amishin@xxxxxxxxxx>
Link: https://patch.msgid.link/20241028065824.15452-1-amishin@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/freescale/fman/fman.c | 1 -
 drivers/net/ethernet/freescale/fman/fman.h | 3 +++
 drivers/net/ethernet/freescale/fman/mac.c  | 5 +++++
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/freescale/fman/fman.c b/drivers/net/ethernet/freescale/fman/fman.c
index d96028f01770c..fb416d60dcd72 100644
--- a/drivers/net/ethernet/freescale/fman/fman.c
+++ b/drivers/net/ethernet/freescale/fman/fman.c
@@ -24,7 +24,6 @@
 
 /* General defines */
 #define FMAN_LIODN_TBL			64	/* size of LIODN table */
-#define MAX_NUM_OF_MACS			10
 #define FM_NUM_OF_FMAN_CTRL_EVENT_REGS	4
 #define BASE_RX_PORTID			0x08
 #define BASE_TX_PORTID			0x28
diff --git a/drivers/net/ethernet/freescale/fman/fman.h b/drivers/net/ethernet/freescale/fman/fman.h
index 2ea575a46675b..74eb62eba0d7f 100644
--- a/drivers/net/ethernet/freescale/fman/fman.h
+++ b/drivers/net/ethernet/freescale/fman/fman.h
@@ -74,6 +74,9 @@
 #define BM_MAX_NUM_OF_POOLS		64 /* Buffers pools */
 #define FMAN_PORT_MAX_EXT_POOLS_NUM	8  /* External BM pools per Rx port */
 
+/* General defines */
+#define MAX_NUM_OF_MACS			10
+
 struct fman; /* FMan data */
 
 /* Enum for defining port types */
diff --git a/drivers/net/ethernet/freescale/fman/mac.c b/drivers/net/ethernet/freescale/fman/mac.c
index 11da139082e1b..1916a2ac48b9f 100644
--- a/drivers/net/ethernet/freescale/fman/mac.c
+++ b/drivers/net/ethernet/freescale/fman/mac.c
@@ -259,6 +259,11 @@ static int mac_probe(struct platform_device *_of_dev)
 		err = -EINVAL;
 		goto _return_dev_put;
 	}
+	if (val >= MAX_NUM_OF_MACS) {
+		dev_err(dev, "cell-index value is too big for %pOF\n", mac_node);
+		err = -EINVAL;
+		goto _return_dev_put;
+	}
 	priv->cell_index = (u8)val;
 
 	/* Get the MAC address */
-- 
2.43.0