[PATCH] mtd: rawnand: tegra: check bounds of die_nr properly

From: Stefan Agner
Date: Wed Jul 04 2018 - 05:13:22 EST


The Tegra driver currently only support a single chip select, hence
check boundaries accordingly. This fixes a off by one issue catched
with Smatch:
drivers/mtd/nand/raw/tegra_nand.c:476 tegra_nand_select_chip()
warn: array off by one? 'nand->cs[die_nr]'

Also warn in case the stack asks for a chip select we currently do
not support.

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
---
drivers/mtd/nand/raw/tegra_nand.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/raw/tegra_nand.c b/drivers/mtd/nand/raw/tegra_nand.c
index 4daa88d814134..e65ef584df0b9 100644
--- a/drivers/mtd/nand/raw/tegra_nand.c
+++ b/drivers/mtd/nand/raw/tegra_nand.c
@@ -468,7 +468,9 @@ static void tegra_nand_select_chip(struct mtd_info *mtd, int die_nr)
struct tegra_nand_chip *nand = to_tegra_chip(chip);
struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);

- if (die_nr < 0 || die_nr > 1) {
+ WARN_ON(die_nr >= ARRAY_SIZE(nand->cs));
+
+ if (die_nr < 0 || die_nr > 0) {
ctrl->cur_cs = -1;
return;
}
--
2.18.0