[PATCH net v3] fsl/fman: Validate cell-index value obtained from Device Tree

From: Aleksandr Mishin
Date: Wed Sep 04 2024 - 02:12:14 EST


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.

Fixes: 414fd46e7762 ("fsl/fman: Add FMan support")
Signed-off-by: Aleksandr Mishin <amishin@xxxxxxxxxx>
Reviewed-by: Sean Anderson <sean.anderson@xxxxxxxx>
---
v3:
- Add Reviewed-by: Sean Anderson <sean.anderson@xxxxxxxx>
(https://lore.kernel.org/all/e0b8c69a-3cc0-4034-b3f7-d8bdcc480c4d@xxxxxxxx/)
v2: https://lore.kernel.org/all/20240702140124.19096-1-amishin@xxxxxxxxxx/
- Move check to mac.c to avoid allmodconfig build errors and reference leaks
v1: https://lore.kernel.org/all/20240702095034.12371-1-amishin@xxxxxxxxxx/

drivers/net/ethernet/freescale/fman/fman.c | 1 -
drivers/net/ethernet/freescale/fman/fman.h | 3 +++
drivers/net/ethernet/freescale/fman/mac.c | 4 ++++
3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/freescale/fman/fman.c b/drivers/net/ethernet/freescale/fman/fman.c
index d96028f01770..fb416d60dcd7 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 2ea575a46675..74eb62eba0d7 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 9767586b4eb3..ac9ad5e67b44 100644
--- a/drivers/net/ethernet/freescale/fman/mac.c
+++ b/drivers/net/ethernet/freescale/fman/mac.c
@@ -247,6 +247,10 @@ static int mac_probe(struct platform_device *_of_dev)
dev_err(dev, "failed to read cell-index for %pOF\n", mac_node);
return -EINVAL;
}
+ if (val >= MAX_NUM_OF_MACS) {
+ dev_err(dev, "cell-index value is too big for %pOF\n", mac_node);
+ return -EINVAL;
+ }
priv->cell_index = (u8)val;

/* Get the MAC address */
--
2.30.2