[PATCH 4/4] s390/zcrypt: fix memleak at release

Johan Hovold
2019-10-10T13:14:57Z

If a process is interrupted while accessing the crypto device and the
global ap_perms_mutex is contented, release() could return early and
fail to free related resources.

Fixes: 00fab2350e6b ("s390/zcrypt: multiple zcrypt device nodes support")
Cc: stable <stable@vger.kernel.org> # 4.19
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/s390/crypto/zcrypt_api.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 45bdb47f84c1..9157e728a362 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -522,8 +522,7 @@ static int zcrypt_release(struct inode *inode, struct file *filp)
if (filp->f_inode->i_cdev == &zcrypt_cdev) {
struct zcdn_device *zcdndev;

- if (mutex_lock_interruptible(&ap_perms_mutex))
- return -ERESTARTSYS;
+ mutex_lock(&ap_perms_mutex);
zcdndev = find_zcdndev_by_devt(filp->f_inode->i_rdev);
mutex_unlock(&ap_perms_mutex);
if (zcdndev) {
--
2.23.0