[PATCH 6.18 394/752] ntb: ntb_hw_switchtec: Fix array-index-out-of-bounds access

Sasha Levin
2026-02-28T17:53:38Z

From: Maciej Grochowski <Maciej.Grochowski@sony.com>

[ Upstream commit c8ba7ad2cc1c7b90570aa347b8ebbe279f1eface ]

Number of MW LUTs depends on NTB configuration and can be set to MAX_MWS,
This patch protects against invalid index out of bounds access to mw_sizes
When invalid access print message to user that configuration is not valid.

Signed-off-by: Maciej Grochowski <Maciej.Grochowski@sony.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
index f851397b65d6e..f15ebab138144 100644
--- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
+++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
@@ -1314,6 +1314,12 @@ static void switchtec_ntb_init_shared(struct switchtec_ntb *sndev)
for (i = 0; i < sndev->nr_lut_mw; i++) {
int idx = sndev->nr_direct_mw + i;

+ if (idx >= MAX_MWS) {
+ dev_err(&sndev->stdev->dev,
+ "Total number of MW cannot be bigger than %d", MAX_MWS);
+ break;
+ }
+
sndev->self_shared->mw_sizes[idx] = LUT_SIZE;
}
}
--
2.51.0