2022-01-26 07:30:23

by Gustavo A. R. Silva

Subject: [PATCH][next] extcon: usbc-cros-ec: Use struct_size() helper in kzalloc()

Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows that,
in the worst scenario, could lead to heap overflows.

Also, address the following sparse warnings:
drivers/extcon/extcon-usbc-cros-ec.c:71:23: warning: using sizeof on a flexible structure

Link: https://github.com/KSPP/linux/issues/174
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/extcon/extcon-usbc-cros-ec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/extcon/extcon-usbc-cros-ec.c b/drivers/extcon/extcon-usbc-cros-ec.c
index 5290cc2d19d9..fde1db62be0d 100644
--- a/drivers/extcon/extcon-usbc-cros-ec.c
+++ b/drivers/extcon/extcon-usbc-cros-ec.c
@@ -68,7 +68,7 @@ static int cros_ec_pd_command(struct cros_ec_extcon_info *info,
struct cros_ec_command *msg;
int ret;

- msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
+ msg = kzalloc(struct_size(msg, data, max(outsize, insize)), GFP_KERNEL);
if (!msg)
return -ENOMEM;

--
2.27.0

2022-02-16 07:07:23

by Gustavo A. R. Silva

Subject: Re: [PATCH][next] extcon: usbc-cros-ec: Use struct_size() helper in kzalloc()

On Wed, Feb 16, 2022 at 10:26:34AM +0900, Chanwoo Choi wrote:
> On 1/26/22 4:26 AM, Gustavo A. R. Silva wrote:
>
> Applied it. Thanks.

Great. :)

Thanks, Chanwoo.
--
Gustavo

2022-02-16 07:18:34

by Chanwoo Choi

Subject: Re: [PATCH][next] extcon: usbc-cros-ec: Use struct_size() helper in kzalloc()

On 1/26/22 4:26 AM, Gustavo A. R. Silva wrote:
> Make use of the struct_size() helper instead of an open-coded version,
> in order to avoid any potential type mistakes or integer overflows that,
> in the worst scenario, could lead to heap overflows.
>
> Also, address the following sparse warnings:
> drivers/extcon/extcon-usbc-cros-ec.c:71:23: warning: using sizeof on a flexible structure
>
> Link: https://protect2.fireeye.com/v1/url?k=2dc5c327-725efa52-2dc44868-0cc47a31ce4e-cb277ab0badba227&q=1&e=e53efbe1-ab25-4a39-a8b1-9e099fcccde3&u=https%3A%2F%2Fgithub.com%2FKSPP%2Flinux%2Fissues%2F174
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> drivers/extcon/extcon-usbc-cros-ec.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/extcon/extcon-usbc-cros-ec.c b/drivers/extcon/extcon-usbc-cros-ec.c
> index 5290cc2d19d9..fde1db62be0d 100644
> --- a/drivers/extcon/extcon-usbc-cros-ec.c
> +++ b/drivers/extcon/extcon-usbc-cros-ec.c
> @@ -68,7 +68,7 @@ static int cros_ec_pd_command(struct cros_ec_extcon_info *info,
> struct cros_ec_command *msg;
> int ret;
>
> - msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
> + msg = kzalloc(struct_size(msg, data, max(outsize, insize)), GFP_KERNEL);
> if (!msg)
> return -ENOMEM;
>
>

Applied it. Thanks.

--
Best Regards,
Chanwoo Choi
Samsung Electronics