2022-10-14 02:28:39

by Yang Yingliang

Subject: [PATCH] platform/loongarch: laptop: fix possible UAF and simplify return in generic_acpi_laptop_init()

Current the return value of 'sub_driver->init' is not checked,
if sparse_keymap_setup() called in the init function fails,
'generic_inputdev' is freed, then it willl lead a UAF when
using it in generic_acpi_laptop_init(). Fix it by checking
return value. Set generic_inputdev to NULL after free to avoid
double free it.

The error code in generic_subdriver_init() is always negative,
the return of generic_subdriver_init() can be simplified.

Fixes: 6246ed09111f ("LoongArch: Add ACPI-based generic laptop driver")
Signed-off-by: Yang Yingliang <[email protected]>
---
drivers/platform/loongarch/loongson-laptop.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/loongarch/loongson-laptop.c b/drivers/platform/loongarch/loongson-laptop.c
index f0166ad5d2c2..572290abf151 100644
--- a/drivers/platform/loongarch/loongson-laptop.c
+++ b/drivers/platform/loongarch/loongson-laptop.c
@@ -448,6 +448,7 @@ static int __init event_init(struct generic_sub_driver *sub_driver)
if (ret < 0) {
pr_err("Failed to setup input device keymap\n");
input_free_device(generic_inputdev);
+ generic_inputdev = NULL;

return ret;
}
@@ -502,8 +503,11 @@ static int __init generic_subdriver_init(struct generic_sub_driver *sub_driver)
if (ret)
return -EINVAL;

- if (sub_driver->init)
- sub_driver->init(sub_driver);
+ if (sub_driver->init) {
+ ret = sub_driver->init(sub_driver);
+ if (ret)
+ goto err_out;
+ }

if (sub_driver->notify) {
ret = setup_acpi_notify(sub_driver);
@@ -519,7 +523,7 @@ static int __init generic_subdriver_init(struct generic_sub_driver *sub_driver)

err_out:
generic_subdriver_exit(sub_driver);
- return (ret < 0) ? ret : 0;
+ return ret;
}

static void generic_subdriver_exit(struct generic_sub_driver *sub_driver)
--
2.25.1

2022-10-14 03:00:37

by Huacai Chen

Subject: Re: [PATCH] platform/loongarch: laptop: fix possible UAF and simplify return in generic_acpi_laptop_init()

Queued for loongarch-fixes, thanks.

Huacai

On Fri, Oct 14, 2022 at 9:52 AM Yang Yingliang <[email protected]> wrote:
>
> Current the return value of 'sub_driver->init' is not checked,
> if sparse_keymap_setup() called in the init function fails,
> 'generic_inputdev' is freed, then it willl lead a UAF when
> using it in generic_acpi_laptop_init(). Fix it by checking
> return value. Set generic_inputdev to NULL after free to avoid
> double free it.
>
> The error code in generic_subdriver_init() is always negative,
> the return of generic_subdriver_init() can be simplified.
>
> Fixes: 6246ed09111f ("LoongArch: Add ACPI-based generic laptop driver")
> Signed-off-by: Yang Yingliang <[email protected]>
> ---
> drivers/platform/loongarch/loongson-laptop.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/platform/loongarch/loongson-laptop.c b/drivers/platform/loongarch/loongson-laptop.c
> index f0166ad5d2c2..572290abf151 100644
> --- a/drivers/platform/loongarch/loongson-laptop.c
> +++ b/drivers/platform/loongarch/loongson-laptop.c
> @@ -448,6 +448,7 @@ static int __init event_init(struct generic_sub_driver *sub_driver)
> if (ret < 0) {
> pr_err("Failed to setup input device keymap\n");
> input_free_device(generic_inputdev);
> + generic_inputdev = NULL;
>
> return ret;
> }
> @@ -502,8 +503,11 @@ static int __init generic_subdriver_init(struct generic_sub_driver *sub_driver)
> if (ret)
> return -EINVAL;
>
> - if (sub_driver->init)
> - sub_driver->init(sub_driver);
> + if (sub_driver->init) {
> + ret = sub_driver->init(sub_driver);
> + if (ret)
> + goto err_out;
> + }
>
> if (sub_driver->notify) {
> ret = setup_acpi_notify(sub_driver);
> @@ -519,7 +523,7 @@ static int __init generic_subdriver_init(struct generic_sub_driver *sub_driver)
>
> err_out:
> generic_subdriver_exit(sub_driver);
> - return (ret < 0) ? ret : 0;
> + return ret;
> }
>
> static void generic_subdriver_exit(struct generic_sub_driver *sub_driver)
> --
> 2.25.1
>