[PATCH] platform/loongarch: laptop: fix possible UAF in generic_acpi_laptop_init()

From: Yang Yingliang
Date: Thu Oct 13 2022 - 09:12:57 EST


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.

Fixes: 6246ed09111f ("LoongArch: Add ACPI-based generic laptop driver")
Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
---
drivers/platform/loongarch/loongson-laptop.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/loongarch/loongson-laptop.c b/drivers/platform/loongarch/loongson-laptop.c
index f0166ad5d2c2..a665fd1042ac 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);
--
2.25.1