2019-04-23 23:32:57

by Wen Yang

[permalink] [raw]

Subject: [PATCH] fpga: stratix10-soc: fix use-after-free on s10_init()

---

The refcount of fw_np has already been decreased by of_find_matching_node()
so it shouldn't be used anymore.
This patch adds an of_node_get() before of_find_matching_node() to avoid
the use-after-free problem.

Fixes: e7eef1d7633a ("fpga: add intel stratix10 soc fpga manager driver")
Signed-off-by: Wen Yang <[email protected]>
Cc: Alan Tull <[email protected]>
Cc: Moritz Fischer <[email protected]>
Cc: Nicolas Saenz Julienne <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
drivers/fpga/stratix10-soc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
index 13851b3..215d337 100644
--- a/drivers/fpga/stratix10-soc.c
+++ b/drivers/fpga/stratix10-soc.c
@@ -507,12 +507,16 @@ static int __init s10_init(void)
if (!fw_np)
return -ENODEV;

+ of_node_get(fw_np);
np = of_find_matching_node(fw_np, s10_of_match);
- if (!np)
+ if (!np) {
+ of_node_put(fw_np);
return -ENODEV;
+ }

of_node_put(np);
ret = of_platform_populate(fw_np, s10_of_match, NULL, NULL);
+ of_node_put(fw_np);
if (ret)
return ret;

--
2.9.5

2019-04-24 00:23:19

by Moritz Fischer

[permalink] [raw]

Subject: Re: [PATCH] fpga: stratix10-soc: fix use-after-free on s10_init()

---

Hi Wen,

On Wed, Apr 24, 2019 at 07:32:05AM +0800, Wen Yang wrote:
> The refcount of fw_np has already been decreased by of_find_matching_node()
> so it shouldn't be used anymore.
> This patch adds an of_node_get() before of_find_matching_node() to avoid
> the use-after-free problem.
>
> Fixes: e7eef1d7633a ("fpga: add intel stratix10 soc fpga manager driver")
> Signed-off-by: Wen Yang <[email protected]>
> Cc: Alan Tull <[email protected]>
> Cc: Moritz Fischer <[email protected]>
> Cc: Nicolas Saenz Julienne <[email protected]>
> Cc: [email protected]
> Cc: [email protected]

Reviewed-by: Moritz Fischer <[email protected]>
> ---
> drivers/fpga/stratix10-soc.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
> index 13851b3..215d337 100644
> --- a/drivers/fpga/stratix10-soc.c
> +++ b/drivers/fpga/stratix10-soc.c
> @@ -507,12 +507,16 @@ static int __init s10_init(void)
> if (!fw_np)
> return -ENODEV;
>
> + of_node_get(fw_np);
> np = of_find_matching_node(fw_np, s10_of_match);
> - if (!np)
> + if (!np) {
> + of_node_put(fw_np);
> return -ENODEV;
> + }
>
> of_node_put(np);
> ret = of_platform_populate(fw_np, s10_of_match, NULL, NULL);
> + of_node_put(fw_np);
> if (ret)
> return ret;
>
> --
> 2.9.5
>

Thanks,
Moritz

2019-04-24 11:48:25

by Nicolas Saenz Julienne

[permalink] [raw]

Subject: Re: [PATCH] fpga: stratix10-soc: fix use-after-free on s10_init()

---

Hi Thanks,

On Wed, 2019-04-24 at 07:32 +0800, Wen Yang wrote:
> The refcount of fw_np has already been decreased by of_find_matching_node()
> so it shouldn't be used anymore.
> This patch adds an of_node_get() before of_find_matching_node() to avoid
> the use-after-free problem.
>
> Fixes: e7eef1d7633a ("fpga: add intel stratix10 soc fpga manager driver")
> Signed-off-by: Wen Yang <[email protected]>
> Cc: Alan Tull <[email protected]>
> Cc: Moritz Fischer <[email protected]>
> Cc: Nicolas Saenz Julienne <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> ---
> drivers/fpga/stratix10-soc.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
> index 13851b3..215d337 100644
> --- a/drivers/fpga/stratix10-soc.c
> +++ b/drivers/fpga/stratix10-soc.c
> @@ -507,12 +507,16 @@ static int __init s10_init(void)
> if (!fw_np)
> return -ENODEV;
>
> + of_node_get(fw_np);
> np = of_find_matching_node(fw_np, s10_of_match);
> - if (!np)
> + if (!np) {
> + of_node_put(fw_np);
> return -ENODEV;
> + }
>
> of_node_put(np);
> ret = of_platform_populate(fw_np, s10_of_match, NULL, NULL);
> + of_node_put(fw_np);
> if (ret)
> return ret;
>


Reviewed-by: Nicolas Saenz Julienne <[email protected]>

Regards,
Nicolas

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