[PATCH] mtd: spi-nor: aspeed-smc: Add of_node_put()

[PATCH] mtd: spi-nor: aspeed-smc: Add of_node_put()

[Nishka Dasgupta]

Each iteration of for_each_available_child_of_node puts the previous
node, but in the case of a break from the middle of the loop, there is
no put, thus causing a memory leak. Upon termination of the loop
(whether by break or a natural exit), either ret will have a non-zero
value or child will be NULL. Hence add an of_node_put() that will
execute only when ret has a non-zero value, as calling of_node_put() on
a possible NULL value does not cause any further issues.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
---
 drivers/mtd/spi-nor/aspeed-smc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/aspeed-smc.c b/drivers/mtd/spi-nor/aspeed-smc.c
index 19b8757325d2..009c1da8574c 100644
--- a/drivers/mtd/spi-nor/aspeed-smc.c
+++ b/drivers/mtd/spi-nor/aspeed-smc.c
@@ -836,8 +836,10 @@ static int aspeed_smc_setup_flash(struct aspeed_smc_controller *controller,
 		controller->chips[cs] = chip;
 	}
 
-	if (ret)
+	if (ret) {
+		of_node_put(child);
 		aspeed_smc_unregister(controller);
+	}
 
 	return ret;
 }
-- 
2.19.1


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Re: [PATCH] mtd: spi-nor: aspeed-smc: Add of_node_put()

[Andrew Jeffery]

On Thu, 8 Aug 2019, at 17:21, Nishka Dasgupta wrote:
> Each iteration of for_each_available_child_of_node puts the previous
> node, but in the case of a break from the middle of the loop, there is
> no put, thus causing a memory leak. Upon termination of the loop
> (whether by break or a natural exit), either ret will have a non-zero
> value or child will be NULL. Hence add an of_node_put() that will
> execute only when ret has a non-zero value, as calling of_node_put() on
> a possible NULL value does not cause any further issues.
> Issue found with Coccinelle.
> 
> Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>

Reviewed-by: Andrew Jeffery <andrew@aj.id.au>

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Re: [PATCH] mtd: spi-nor: aspeed-smc: Add of_node_put()

[Tudor.Ambarus]

On 08/08/2019 10:51 AM, Nishka Dasgupta wrote:
> External E-Mail
> 
> 
> Each iteration of for_each_available_child_of_node puts the previous
> node, but in the case of a break from the middle of the loop, there is
> no put, thus causing a memory leak. Upon termination of the loop
> (whether by break or a natural exit), either ret will have a non-zero
> value or child will be NULL. Hence add an of_node_put() that will
> execute only when ret has a non-zero value, as calling of_node_put() on
> a possible NULL value does not cause any further issues.
> Issue found with Coccinelle.
> 
> Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
> ---
>  drivers/mtd/spi-nor/aspeed-smc.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git,
spi-nor/next branch.

Thanks,
ta
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