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

From: Su Hui
Date: Sun May 19 2024 - 22:20:42 EST


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 <suhui@xxxxxxxxxxxx>
---
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