s390/zcrypt: fix memleak at release

commit 388bb19be8eab4674a660e0c97eaf60775362bc7 upstream.

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@vger.kernel.org> # 4.19
Cc: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 1058b4b5cc1ec5d1b8ccb4c6e70f803e163507a3..35a0e956923902a3336536790a54c4070d21ce1c 100644 (file)
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -539,8 +539,7 @@ 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) {