[PATCH 1/2] crypto/ccp: Cleanup misc_dev on sev_exit()

From: John Allen
Date: Tue Mar 03 2020 - 08:57:57 EST


Explicitly free and clear misc_dev in sev_exit(). Since devm_kzalloc()
associates misc_dev with the first device that gets probed, change from
devm_kzalloc() to kzalloc() and explicitly free memory in sev_exit() as
the first device probed is not guaranteed to be the last device released.
To ensure that the variable gets properly set to NULL, remove the local
definition of misc_dev.

Fixes: 200664d5237f ("crypto: ccp: Add Secure Encrypted Virtualization (SEV) command support")
Signed-off-by: John Allen <john.allen@xxxxxxx>
---
drivers/crypto/ccp/sev-dev.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index e467860f797d..aa591dae067c 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -896,9 +896,9 @@ EXPORT_SYMBOL_GPL(sev_guest_df_flush);

static void sev_exit(struct kref *ref)
{
- struct sev_misc_dev *misc_dev = container_of(ref, struct sev_misc_dev, refcount);
-
misc_deregister(&misc_dev->misc);
+ kfree(misc_dev);
+ misc_dev = NULL;
}

static int sev_misc_init(struct sev_device *sev)
@@ -916,7 +916,7 @@ static int sev_misc_init(struct sev_device *sev)
if (!misc_dev) {
struct miscdevice *misc;

- misc_dev = devm_kzalloc(dev, sizeof(*misc_dev), GFP_KERNEL);
+ misc_dev = kzalloc(sizeof(*misc_dev), GFP_KERNEL);
if (!misc_dev)
return -ENOMEM;

--
2.18.2