On Tue, Jun 4 2024 at 11:41:24 PM +02:00:00, Thomas Weißschuh
<linux@xxxxxxxxxxxxxx> 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 Weißschuh <linux@xxxxxxxxxxxxxx>
---
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 <linux@xxxxxxxxxxxxxx>
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 <lsanche@xxxxxxxxxx>
