Re: [PATCH] spi: oc-tiny: fix negative loop bound error on for loop

[Mukesh Ojha]

On 3/31/2019 2:53 AM, Colin King wrote:
From: Colin Ian King <colin.k...@canonical.com>

Currently the for-loop using an unsigned int for the loop counter
which is problematic when comparing it to the signed int
gt->gpio_cs_count.  This is an issue because if the signed int is
negative (for example, the call to of_gpio_count failed) then
the negative loop bound is implicitly cast to an unsigned int on
the comparison to loop counter i and will yield a very large value,
eventually causing an array bounds overflow on hw->gpio_cs.

Fix this by simply making the loop counter i a signed int;

Fixes: ca632f556697 ("spi: reorganize drivers")
Signed-off-by: Colin Ian King <colin.k...@canonical.com>
---
  drivers/spi/spi-oc-tiny.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-oc-tiny.c b/drivers/spi/spi-oc-tiny.c
index 085f580be7ec..81f74b938dc9 100644
--- a/drivers/spi/spi-oc-tiny.c
+++ b/drivers/spi/spi-oc-tiny.c
@@ -206,7 +206,7 @@ static int tiny_spi_of_probe(struct platform_device *pdev)
  {
        struct tiny_spi *hw = platform_get_drvdata(pdev);
        struct device_node *np = pdev->dev.of_node;
-       unsigned int i;
+       int i;


same here as well you are putting wrapper over a original issue by not 
checking the returned value.
Please fix that in both patches.



Thanks.
Mukesh

        u32 val;
  
  	if (!np)