[PATCH] platform/x86/intel/tpmi: Fix double free reported by Smatch

From: Srinivas Pandruvada
Date: Mon Feb 27 2023 - 09:08:32 EST


Fix warning:
drivers/platform/x86/intel/tpmi.c:253 tpmi_create_device()
warn: 'feature_vsec_dev' was already freed.

If there is some error, feature_vsec_dev memory is freed as part
of resource managed call intel_vsec_add_aux(). So, additional
kfree() call is not required.

Reordered res allocation and feature_vsec_dev, so that on error
only res is freed.

Reported-by: Dan Carpenter <error27@xxxxxxxxx>
Link: https://lore.kernel.org/platform-driver-x86/Y%2FxYR7WGiPayZu%2FR@kili/T/#u
Fixes: 47731fd2865f ("platform/x86/intel: Intel TPMI enumeration driver")
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
---
drivers/platform/x86/intel/tpmi.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/platform/x86/intel/tpmi.c b/drivers/platform/x86/intel/tpmi.c
index c60733261c89..c999732b0f1e 100644
--- a/drivers/platform/x86/intel/tpmi.c
+++ b/drivers/platform/x86/intel/tpmi.c
@@ -209,14 +209,14 @@ static int tpmi_create_device(struct intel_tpmi_info *tpmi_info,
if (!name)
return -EOPNOTSUPP;

- feature_vsec_dev = kzalloc(sizeof(*feature_vsec_dev), GFP_KERNEL);
- if (!feature_vsec_dev)
+ res = kcalloc(pfs->pfs_header.num_entries, sizeof(*res), GFP_KERNEL);
+ if (!res)
return -ENOMEM;

- res = kcalloc(pfs->pfs_header.num_entries, sizeof(*res), GFP_KERNEL);
- if (!res) {
+ feature_vsec_dev = kzalloc(sizeof(*feature_vsec_dev), GFP_KERNEL);
+ if (!feature_vsec_dev) {
ret = -ENOMEM;
- goto free_vsec;
+ goto free_res;
}

snprintf(feature_id_name, sizeof(feature_id_name), "tpmi-%s", name);
@@ -239,6 +239,8 @@ static int tpmi_create_device(struct intel_tpmi_info *tpmi_info,
/*
* intel_vsec_add_aux() is resource managed, no explicit
* delete is required on error or on module unload.
+ * feature_vsec_dev memory is also freed as part of device
+ * delete.
*/
ret = intel_vsec_add_aux(vsec_dev->pcidev, &vsec_dev->auxdev.dev,
feature_vsec_dev, feature_id_name);
@@ -249,8 +251,6 @@ static int tpmi_create_device(struct intel_tpmi_info *tpmi_info,

free_res:
kfree(res);
-free_vsec:
- kfree(feature_vsec_dev);

return ret;
}
--
2.39.1