[PATCH v1 1/2] s390/zcrtpt: Don't leak memory if dev_set_name() fails

[PATCH v1 1/2] s390/zcrtpt: Don't leak memory if dev_set_name() fails

[Andy Shevchenko]

When dev_set_name() fails, the zcdn_create() doesn't free
the newly allocated resources. Do it.

Fixes: 00fab2350e6b ("s390/zcrypt: multiple zcrypt device nodes support")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/s390/crypto/zcrypt_api.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 4b23c9f7f3e5..6b99f7dd0643 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -413,6 +413,7 @@ static int zcdn_create(const char *name)
 			 ZCRYPT_NAME "_%d", (int)MINOR(devt));
 	nodename[sizeof(nodename) - 1] = '\0';
 	if (dev_set_name(&zcdndev->device, nodename)) {
+		kfree(zcdndev);
 		rc = -EINVAL;
 		goto unlockout;
 	}
-- 
2.40.0.1.gaa8946217a0b

[PATCH v1 2/2] s390/zcrypt: Utilize dev_set_name() ability to use a formatted string

[Andy Shevchenko]

With the dev_set_name() prototype it's not obvious that it takes
a formatted string as a parameter. Use its facility instead of
duplicating the same with strncpy()/snprintf() calls.

With this, also prevent return error code to be shadowed.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/s390/crypto/zcrypt_api.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 6b99f7dd0643..ce04caa7913f 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -366,7 +366,6 @@ static int zcdn_create(const char *name)
 {
 	dev_t devt;
 	int i, rc = 0;
-	char nodename[ZCDN_MAX_NAME];
 	struct zcdn_device *zcdndev;
 
 	if (mutex_lock_interruptible(&ap_perms_mutex))
@@ -407,14 +406,11 @@ static int zcdn_create(const char *name)
 	zcdndev->device.devt = devt;
 	zcdndev->device.groups = zcdn_dev_attr_groups;
 	if (name[0])
-		strncpy(nodename, name, sizeof(nodename));
+		rc = dev_set_name(&zcdndev->device, "%s", name);
 	else
-		snprintf(nodename, sizeof(nodename),
-			 ZCRYPT_NAME "_%d", (int)MINOR(devt));
-	nodename[sizeof(nodename) - 1] = '\0';
-	if (dev_set_name(&zcdndev->device, nodename)) {
+		rc = dev_set_name(&zcdndev->device, ZCRYPT_NAME "_%d", (int)MINOR(devt));
+	if (rc) {
 		kfree(zcdndev);
-		rc = -EINVAL;
 		goto unlockout;
 	}
 	rc = device_register(&zcdndev->device);
-- 
2.40.0.1.gaa8946217a0b

Re: [PATCH v1 1/2] s390/zcrtpt: Don't leak memory if dev_set_name() fails

[Harald Freudenberger]

On 2023-08-31 12:59, Andy Shevchenko wrote:
> When dev_set_name() fails, the zcdn_create() doesn't free
> the newly allocated resources. Do it.
> 
> Fixes: 00fab2350e6b ("s390/zcrypt: multiple zcrypt device nodes 
> support")
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  drivers/s390/crypto/zcrypt_api.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/s390/crypto/zcrypt_api.c 
> b/drivers/s390/crypto/zcrypt_api.c
> index 4b23c9f7f3e5..6b99f7dd0643 100644
> --- a/drivers/s390/crypto/zcrypt_api.c
> +++ b/drivers/s390/crypto/zcrypt_api.c
> @@ -413,6 +413,7 @@ static int zcdn_create(const char *name)
>  			 ZCRYPT_NAME "_%d", (int)MINOR(devt));
>  	nodename[sizeof(nodename) - 1] = '\0';
>  	if (dev_set_name(&zcdndev->device, nodename)) {
> +		kfree(zcdndev);
>  		rc = -EINVAL;
>  		goto unlockout;
>  	}
Thanks Andy, I picked this patch and forwarded it into the s390 
subsystem.
This will be visible in Linus' kernel tree with the next merge.