[PATCH] drivers/platform/x86/amd: pmf: Fix a double free on module unload

[Mario Limonciello <superm1@kernel.org>]

From: Mario Limonciello <mario.limonciello@amd.com>

If setting up smart PC fails for any reason then this can lead to
a double free when unloading amd-pmf.  This is because dev->buf was
freed but never set to NULL and is again freed in
amd_pmf_deinit_smart_pc().

Explicitly set pointers to NULL after freeing them to avoid the
double free.

Fixes: 5b1122fc4995f ("platform/x86/amd/pmf: fix cleanup in amd_pmf_init_smart_pc()")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/platform/x86/amd/pmf/tee-if.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/platform/x86/amd/pmf/tee-if.c b/drivers/platform/x86/amd/pmf/tee-if.c
index a1e43873a07b0..48902f1c767c6 100644
--- a/drivers/platform/x86/amd/pmf/tee-if.c
+++ b/drivers/platform/x86/amd/pmf/tee-if.c
@@ -579,10 +579,13 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev)
 	amd_pmf_tee_deinit(dev);
 err_free_prev_data:
 	kfree(dev->prev_data);
+	dev->prev_data = NULL;
 err_free_policy:
 	kfree(dev->policy_buf);
+	dev->policy_buf = NULL;
 err_free_dram_buf:
 	kfree(dev->buf);
+	dev->buf = NULL;
 err_cancel_work:
 	cancel_delayed_work_sync(&dev->pb_work);
 
-- 
2.43.0