4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: "Jason J. Herne" <jjherne@xxxxxxxxxxxxxxxxxx>
[ Upstream commit 408358b50deaf59b07c82a7bff8c7e7cce031fae ]
Because we do not make use of the cda (channel data address) for test,
no-op ccws no address translation takes place. This means cda could
contain a guest address which we do not want to attempt to free. Let's
check the command type and skip cda free when it is not needed.
For a TIC ccw, ccw->cda points to either a ccw in an existing chain or
it points to a whole new allocated chain. In either case the data will
be freed when the owning chain is freed.
Signed-off-by: Jason J. Herne <jjherne@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Dong Jia Shi <bjsdjshi@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Pierre Morel <pmorel@xxxxxxxxxxxxxxxxxx>
Message-Id: <1510068152-21988-1-git-send-email-jjherne@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxxxxxxx>
Acked-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Signed-off-by: Cornelia Huck <cohuck@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/s390/cio/vfio_ccw_cp.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -330,6 +330,8 @@ static void ccwchain_cda_free(struct ccw
{
struct ccw1 *ccw = chain->ch_ccw + idx;
+ if (ccw_is_test(ccw) || ccw_is_noop(ccw) || ccw_is_tic(ccw))
+ return;
if (!ccw->count)
return;