From: Qinglang Miao Date: Tue, 1 Dec 2020 14:31:50 +0800 Subject: s390/cio: fix use-after-free in ccw_device_destroy_console Git-commit: 14d4c4fa46eeaa3922e8e1c4aa727eb0a1412804 Patch-mainline: v5.11-rc1 References: git-fixes Use of sch->dev reference after the put_device() call could trigger the use-after-free bugs. Fix this by simply adjusting the position of put_device. Fixes: 37db8985b211 ("s390/cio: add basic protected virtualization support") Reported-by: Hulk Robot Suggested-by: Cornelia Huck Signed-off-by: Qinglang Miao Reviewed-by: Cornelia Huck Reviewed-by: Vineeth Vijayan [vneethv@linux.ibm.com: Slight modification in the commit-message] Signed-off-by: Vineeth Vijayan Signed-off-by: Heiko Carstens Acked-by: Petr Tesarik --- drivers/s390/cio/device.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/s390/cio/device.c +++ b/drivers/s390/cio/device.c @@ -1664,10 +1664,10 @@ void __init ccw_device_destroy_console(s 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); }