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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Harald Freudenberger <freude@linux.ibm.com>,
        Johan Hovold <johan@kernel.org>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>
Subject: [PATCH 5.3 158/197] s390/zcrypt: fix memleak at release
Date:   Sun, 27 Oct 2019 22:01:16 +0100
Message-Id: <20191027203400.212151946@linuxfoundation.org>
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From: Johan Hovold <johan@kernel.org>

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>

---
 drivers/s390/crypto/zcrypt_api.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -539,8 +539,7 @@ static int zcrypt_release(struct inode *
 	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) {