From: Qinglang Miao <miaoqinglang@huawei.com>
To: Vineeth Vijayan <vneethv@linux.ibm.com>,
Peter Oberparleiter <oberpar@linux.ibm.com>,
Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Christian Borntraeger <borntraeger@de.ibm.com>
Cc: <linux-s390@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
"Qinglang Miao" <miaoqinglang@huawei.com>
Subject: [PATCH] s390: cio: fix two use-after-free bugs in device.c
Date: Fri, 20 Nov 2020 15:48:49 +0800 [thread overview]
Message-ID: <20201120074849.31557-1-miaoqinglang@huawei.com> (raw)
put_device calls release function which do kfree() inside.
So following use of sch&cdev would cause use-after-free bugs.
Fix these by simply adjusting the position of put_device.
Fixes: 37db8985b211 ("s390/cio: add basic protected virtualization support")
Fixes: 74bd0d859dc3 ("s390/cio: fix unlocked access of online member")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
---
drivers/s390/cio/device.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index b29fe8d50..69492417b 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1664,10 +1664,10 @@ void __init ccw_device_destroy_console(struct ccw_device *cdev)
struct io_subchannel_private *io_priv = to_io_private(sch);
set_io_private(sch, NULL);
- put_device(&sch->dev);
- put_device(&cdev->dev);
dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
io_priv->dma_area, io_priv->dma_area_dma);
+ put_device(&sch->dev);
+ put_device(&cdev->dev);
kfree(io_priv);
}
@@ -1774,8 +1774,8 @@ static int ccw_device_remove(struct device *dev)
ret, cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
/* Give up reference obtained in ccw_device_set_online(). */
- put_device(&cdev->dev);
spin_lock_irq(cdev->ccwlock);
+ put_device(&cdev->dev);
}
ccw_device_set_timeout(cdev, 0);
cdev->drv = NULL;
--
2.23.0
next reply other threads:[~2020-11-20 7:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-20 7:48 Qinglang Miao [this message]
2020-11-20 7:55 ` [PATCH] s390: cio: fix two use-after-free bugs in device.c Cornelia Huck
2020-12-01 6:31 ` Qinglang Miao
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