[PATCH net v4] fsl/fman: Validate cell-index value obtained from Device Tree

[PATCH net v4] fsl/fman: Validate cell-index value obtained from Device Tree

[Aleksandr Mishin]

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")
Reviewed-by: Sean Anderson <sean.anderson@seco.com>
Signed-off-by: Aleksandr Mishin <amishin@t-argos.ru>
---
v4:
  - Update patch after refcount leaks fix
    (https://lore.kernel.org/all/20241015060122.25709-1-amishin@t-argos.ru/)
	as suggested by Jakub
	(https://lore.kernel.org/all/20240904072307.1b17227c@kernel.org/)
v3: https://lore.kernel.org/all/20240904060920.9645-1-amishin@t-argos.ru/
  - Add Reviewed-by: Sean Anderson <sean.anderson@seco.com>
    (https://lore.kernel.org/all/e0b8c69a-3cc0-4034-b3f7-d8bdcc480c4d@seco.com/)
v2: https://lore.kernel.org/all/20240702140124.19096-1-amishin@t-argos.ru/
  - Move check to mac.c to avoid allmodconfig build errors and reference leaks
v1: https://lore.kernel.org/all/20240702095034.12371-1-amishin@t-argos.ru/

 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 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 11da139082e1..1916a2ac48b9 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 */
-- 
2.30.2

Re: [PATCH net v4] fsl/fman: Validate cell-index value obtained from Device Tree

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Mon, 28 Oct 2024 09:58:24 +0300 you wrote:
> 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.
> 
> [...]

Here is the summary with links:
  - [net,v4] fsl/fman: Validate cell-index value obtained from Device Tree
    https://git.kernel.org/netdev/net-next/c/bd50c4125c98

You are awesome, thank you!
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