If platform_profile_register() fails it does kfree(thermal_handler) and
leaves the pointer value around.
Any call to thermal_cleanup() will try to kfree(thermal_handler) again.
This will happen right away in dell_init().
In addition, platform_profile_remove() will be called although no
profile is registered.
NULL out the thermal_handler, so thermal_cleanup() avoids the double free.
Fixes: 996ad4129810 ("platform/x86: dell-pc: Implement platform_profile")
Signed-off-by: Thomas Weißschuh <[email protected]>
---
Currently the call to thermal_cleanup() in dell_init() is completely
unnecessary. But I guess more functionality will be handled by the
driver and then this structure makes sense.
This is untested.
---
drivers/platform/x86/dell/dell-pc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/platform/x86/dell/dell-pc.c b/drivers/platform/x86/dell/dell-pc.c
index dfe09c463d03..972385ca1990 100644
--- a/drivers/platform/x86/dell/dell-pc.c
+++ b/drivers/platform/x86/dell/dell-pc.c
@@ -261,8 +261,10 @@ static int thermal_init(void)
/* Clean up if failed */
ret = platform_profile_register(thermal_handler);
- if (ret)
+ if (ret) {
kfree(thermal_handler);
+ thermal_handler = NULL;
+ }
return ret;
}
---
base-commit: 0da7a954480cc99978e3570c991e3779e56fc736
change-id: 20240604-dell-pc-double-free-e8cf2aa9b2fb
Best regards,
--
Thomas Weißschuh <[email protected]>
On Tue, Jun 4 2024 at 11:41:24 PM +02:00:00, Thomas Wei?schuh
<[email protected]> wrote:
> If platform_profile_register() fails it does kfree(thermal_handler)
> and
> leaves the pointer value around.
> Any call to thermal_cleanup() will try to kfree(thermal_handler)
> again.
> This will happen right away in dell_init().
> In addition, platform_profile_remove() will be called although no
> profile is registered.
>
> NULL out the thermal_handler, so thermal_cleanup() avoids the double
> free.
>
> Fixes: 996ad4129810 ("platform/x86: dell-pc: Implement
> platform_profile")
> Signed-off-by: Thomas Wei?schuh <[email protected]>
> ---
> Currently the call to thermal_cleanup() in dell_init() is completely
> unnecessary. But I guess more functionality will be handled by the
> driver and then this structure makes sense.
>
> This is untested.
> ---
> drivers/platform/x86/dell/dell-pc.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/dell/dell-pc.c
> b/drivers/platform/x86/dell/dell-pc.c
> index dfe09c463d03..972385ca1990 100644
> --- a/drivers/platform/x86/dell/dell-pc.c
> +++ b/drivers/platform/x86/dell/dell-pc.c
> @@ -261,8 +261,10 @@ static int thermal_init(void)
>
> /* Clean up if failed */
> ret = platform_profile_register(thermal_handler);
> - if (ret)
> + if (ret) {
> kfree(thermal_handler);
> + thermal_handler = NULL;
> + }
>
> return ret;
> }
>
> ---
> base-commit: 0da7a954480cc99978e3570c991e3779e56fc736
> change-id: 20240604-dell-pc-double-free-e8cf2aa9b2fb
>
> Best regards,
> --
> Thomas Wei?schuh <[email protected]>
Thank you for this patch. I was able to apply your patch and compile
successfully. I have not had a chance to try it on my hardware.
I agree with the change, and it looks good to me.
Thanks,
Reviewed-by: Lyndon Sanche <[email protected]>
On Tue, 04 Jun 2024 23:41:24 +0200, Thomas Weißschuh wrote:
> If platform_profile_register() fails it does kfree(thermal_handler) and
> leaves the pointer value around.
> Any call to thermal_cleanup() will try to kfree(thermal_handler) again.
> This will happen right away in dell_init().
> In addition, platform_profile_remove() will be called although no
> profile is registered.
>
> [...]
Thank you for your contribution, it has been applied to my local
review-ilpo branch. Note it will show up in the public
platform-drivers-x86/review-ilpo branch only once I've pushed my
local branch there, which might take a while.
The list of commits applied:
[1/1] platform/x86: dell-pc: avoid double free and invalid unregistration
commit: dd637f5cd5f334d2d014872544470031415cec3b
--
i.