This is a note to let you know that I've just added the patch titled

s390: vfio-ccw: Do not attempt to free no-op, test and tic cda.

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: s390-vfio-ccw-do-not-attempt-to-free-no-op-test-and-tic-cda.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Wed Dec 6 18:04:41 CET 2017

From: "Jason J. Herne" jjherne@linux.vnet.ibm.com Date: Tue, 7 Nov 2017 10:22:32 -0500 Subject: s390: vfio-ccw: Do not attempt to free no-op, test and tic cda.

From: "Jason J. Herne" jjherne@linux.vnet.ibm.com

[ 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@linux.vnet.ibm.com Reviewed-by: Dong Jia Shi bjsdjshi@linux.vnet.ibm.com Reviewed-by: Pierre Morel pmorel@linux.vnet.ibm.com Message-Id: 1510068152-21988-1-git-send-email-jjherne@linux.vnet.ibm.com Reviewed-by: Halil Pasic pasic@linux.vnet.ibm.com Acked-by: Christian Borntraeger borntraeger@de.ibm.com Signed-off-by: Cornelia Huck cohuck@redhat.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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;

Patches currently in stable-queue which might be from jjherne@linux.vnet.ibm.com are

queue-4.14/s390-vfio-ccw-do-not-attempt-to-free-no-op-test-and-tic-cda.patch