2024-05-20 02:20:42

by Su Hui

Subject: [PATCH] platform/x86: ISST: fix use after free problem in tpmi_sst_dev_remove()

clang static checker (scan-build) warning:
drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c:1614:24:
Use of memory after it is freed.

Using 'tpmi_sst->package_id' after releasing 'tpmi_sst' causes this
problem. Change the order of releasing 'tpmi_sst' to fix this.

Fixes: 9d1d36268f3d ("platform/x86: ISST: Support partitioned systems")
Signed-off-by: Su Hui <[email protected]>
---
drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
index 7bac7841ff0a..7fa360073f6e 100644
--- a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
+++ b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
@@ -1610,8 +1610,8 @@ void tpmi_sst_dev_remove(struct auxiliary_device *auxdev)
tpmi_sst->partition_mask_current &= ~BIT(plat_info->partition);
/* Free the package instance when the all partitions are removed */
if (!tpmi_sst->partition_mask_current) {
- kfree(tpmi_sst);
isst_common.sst_inst[tpmi_sst->package_id] = NULL;
+ kfree(tpmi_sst);
}
mutex_unlock(&isst_tpmi_dev_lock);
}
--
2.30.2

2024-05-20 05:24:23

by Harshit Mogalapalli

Subject: Re: [PATCH] platform/x86: ISST: fix use after free problem in tpmi_sst_dev_remove()

Hi Su Hui,

On 20/05/24 07:49, Su Hui wrote:
> clang static checker (scan-build) warning:
> drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c:1614:24:
> Use of memory after it is freed.
>
> Using 'tpmi_sst->package_id' after releasing 'tpmi_sst' causes this
> problem. Change the order of releasing 'tpmi_sst' to fix this.
>

This is fixed by me already.
Ref:
https://lore.kernel.org/all/[email protected]/

Thanks,
Harshit
> Fixes: 9d1d36268f3d ("platform/x86: ISST: Support partitioned systems")
> Signed-off-by: Su Hui <[email protected]>
> ---
> drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
> index 7bac7841ff0a..7fa360073f6e 100644
> --- a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
> +++ b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
> @@ -1610,8 +1610,8 @@ void tpmi_sst_dev_remove(struct auxiliary_device *auxdev)
> tpmi_sst->partition_mask_current &= ~BIT(plat_info->partition);
> /* Free the package instance when the all partitions are removed */
> if (!tpmi_sst->partition_mask_current) {
> - kfree(tpmi_sst);
> isst_common.sst_inst[tpmi_sst->package_id] = NULL;
> + kfree(tpmi_sst);
> }
> mutex_unlock(&isst_tpmi_dev_lock);
> }