* [PATCH v2] mtd: rawnand: atmel: Fix potential NULL pointer dereference
@ 2018-09-18 13:55 Gustavo A. R. Silva
2018-09-18 13:58 ` Boris Brezillon
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Gustavo A. R. Silva @ 2018-09-18 13:55 UTC (permalink / raw)
To: Tudor Ambarus, Boris Brezillon, Miquel Raynal,
Richard Weinberger, David Woodhouse, Brian Norris, Marek Vasut,
Nicolas Ferre, Alexandre Belloni, Ludovic Desroches
Cc: linux-mtd, linux-arm-kernel, linux-kernel, Gustavo A. R. Silva
There is a potential execution path in which function
of_find_compatible_node() returns NULL. In such a case,
we end up having a NULL pointer dereference when accessing
pointer *nfc_np* in function of_clk_get().
So, we better don't take any chances and fix this by null
checking pointer *nfc_np* before calling of_clk_get().
Addresses-Coverity-ID: 1473052 ("Dereference null return value")
Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
Changes in v2:
- Add Fixes tag to the commit log.
- Remove blank line before null checking nfc_np.
drivers/mtd/nand/raw/atmel/nand-controller.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c
index a38633a..5bfbe97 100644
--- a/drivers/mtd/nand/raw/atmel/nand-controller.c
+++ b/drivers/mtd/nand/raw/atmel/nand-controller.c
@@ -2034,6 +2034,10 @@ atmel_hsmc_nand_controller_legacy_init(struct atmel_hsmc_nand_controller *nc)
nand_np = dev->of_node;
nfc_np = of_find_compatible_node(dev->of_node, NULL,
"atmel,sama5d3-nfc");
+ if (!nfc_np) {
+ dev_err(dev, "Could not find device node for sama5d3-nfc\n");
+ return -ENODEV;
+ }
nc->clk = of_clk_get(nfc_np, 0);
if (IS_ERR(nc->clk)) {
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] mtd: rawnand: atmel: Fix potential NULL pointer dereference
2018-09-18 13:55 [PATCH v2] mtd: rawnand: atmel: Fix potential NULL pointer dereference Gustavo A. R. Silva
@ 2018-09-18 13:58 ` Boris Brezillon
2018-09-19 7:44 ` Tudor Ambarus
2018-09-19 21:27 ` Miquel Raynal
2 siblings, 0 replies; 4+ messages in thread
From: Boris Brezillon @ 2018-09-18 13:58 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Tudor Ambarus, Miquel Raynal, Richard Weinberger,
David Woodhouse, Brian Norris, Marek Vasut, Nicolas Ferre,
Alexandre Belloni, Ludovic Desroches, linux-mtd,
linux-arm-kernel, linux-kernel
On Tue, 18 Sep 2018 08:55:55 -0500
"Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote:
> There is a potential execution path in which function
> of_find_compatible_node() returns NULL. In such a case,
> we end up having a NULL pointer dereference when accessing
> pointer *nfc_np* in function of_clk_get().
>
> So, we better don't take any chances and fix this by null
> checking pointer *nfc_np* before calling of_clk_get().
>
> Addresses-Coverity-ID: 1473052 ("Dereference null return value")
> Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
> ---
> Changes in v2:
> - Add Fixes tag to the commit log.
> - Remove blank line before null checking nfc_np.
>
> drivers/mtd/nand/raw/atmel/nand-controller.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c
> index a38633a..5bfbe97 100644
> --- a/drivers/mtd/nand/raw/atmel/nand-controller.c
> +++ b/drivers/mtd/nand/raw/atmel/nand-controller.c
> @@ -2034,6 +2034,10 @@ atmel_hsmc_nand_controller_legacy_init(struct atmel_hsmc_nand_controller *nc)
> nand_np = dev->of_node;
> nfc_np = of_find_compatible_node(dev->of_node, NULL,
> "atmel,sama5d3-nfc");
> + if (!nfc_np) {
> + dev_err(dev, "Could not find device node for sama5d3-nfc\n");
> + return -ENODEV;
> + }
>
> nc->clk = of_clk_get(nfc_np, 0);
> if (IS_ERR(nc->clk)) {
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] mtd: rawnand: atmel: Fix potential NULL pointer dereference
2018-09-18 13:55 [PATCH v2] mtd: rawnand: atmel: Fix potential NULL pointer dereference Gustavo A. R. Silva
2018-09-18 13:58 ` Boris Brezillon
@ 2018-09-19 7:44 ` Tudor Ambarus
2018-09-19 21:27 ` Miquel Raynal
2 siblings, 0 replies; 4+ messages in thread
From: Tudor Ambarus @ 2018-09-19 7:44 UTC (permalink / raw)
To: Gustavo A. R. Silva, Boris Brezillon, Miquel Raynal,
Richard Weinberger, David Woodhouse, Brian Norris, Marek Vasut,
Nicolas Ferre, Alexandre Belloni, Ludovic Desroches
Cc: linux-mtd, linux-arm-kernel, linux-kernel
On 09/18/2018 04:55 PM, Gustavo A. R. Silva wrote:
> There is a potential execution path in which function
> of_find_compatible_node() returns NULL. In such a case,
> we end up having a NULL pointer dereference when accessing
> pointer *nfc_np* in function of_clk_get().
>
> So, we better don't take any chances and fix this by null
> checking pointer *nfc_np* before calling of_clk_get().
>
> Addresses-Coverity-ID: 1473052 ("Dereference null return value")
> Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> ---
> Changes in v2:
> - Add Fixes tag to the commit log.
> - Remove blank line before null checking nfc_np.
>
> drivers/mtd/nand/raw/atmel/nand-controller.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c
> index a38633a..5bfbe97 100644
> --- a/drivers/mtd/nand/raw/atmel/nand-controller.c
> +++ b/drivers/mtd/nand/raw/atmel/nand-controller.c
> @@ -2034,6 +2034,10 @@ atmel_hsmc_nand_controller_legacy_init(struct atmel_hsmc_nand_controller *nc)
> nand_np = dev->of_node;
> nfc_np = of_find_compatible_node(dev->of_node, NULL,
> "atmel,sama5d3-nfc");
> + if (!nfc_np) {
> + dev_err(dev, "Could not find device node for sama5d3-nfc\n");
> + return -ENODEV;
> + }
>
> nc->clk = of_clk_get(nfc_np, 0);
> if (IS_ERR(nc->clk)) {
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] mtd: rawnand: atmel: Fix potential NULL pointer dereference
2018-09-18 13:55 [PATCH v2] mtd: rawnand: atmel: Fix potential NULL pointer dereference Gustavo A. R. Silva
2018-09-18 13:58 ` Boris Brezillon
2018-09-19 7:44 ` Tudor Ambarus
@ 2018-09-19 21:27 ` Miquel Raynal
2 siblings, 0 replies; 4+ messages in thread
From: Miquel Raynal @ 2018-09-19 21:27 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Tudor Ambarus, Boris Brezillon, Richard Weinberger,
David Woodhouse, Brian Norris, Marek Vasut, Nicolas Ferre,
Alexandre Belloni, Ludovic Desroches, linux-mtd,
linux-arm-kernel, linux-kernel
Hi Gustavo,
"Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote on Tue, 18 Sep
2018 08:55:55 -0500:
> There is a potential execution path in which function
> of_find_compatible_node() returns NULL. In such a case,
> we end up having a NULL pointer dereference when accessing
> pointer *nfc_np* in function of_clk_get().
>
> So, we better don't take any chances and fix this by null
> checking pointer *nfc_np* before calling of_clk_get().
>
> Addresses-Coverity-ID: 1473052 ("Dereference null return value")
> Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
Applied to nand/next.
Thanks,
Miquèl
^ permalink raw reply [flat|nested] 4+ messages in thread
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2018-09-18 13:55 [PATCH v2] mtd: rawnand: atmel: Fix potential NULL pointer dereference Gustavo A. R. Silva
2018-09-18 13:58 ` Boris Brezillon
2018-09-19 7:44 ` Tudor Ambarus
2018-09-19 21:27 ` Miquel Raynal
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