FAILED: patch "[PATCH] s390/vfio_ccw: Cancel existing workqueues" failed to apply to 5.10-stable tree

FAILED: patch "[PATCH] s390/vfio_ccw: Cancel existing workqueues" failed to apply to 5.10-stable tree

[gregkh]

The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 79c60b2c61105368dcc8444eb45847e21734f7c4
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026082041-cheek-expert-0782@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 79c60b2c61105368dcc8444eb45847e21734f7c4 Mon Sep 17 00:00:00 2001
From: Eric Farman <farman@linux.ibm.com>
Date: Tue, 28 Jul 2026 05:30:19 +0200
Subject: [PATCH] s390/vfio_ccw: Cancel existing workqueues

The initialization of the io_work and crw_work workqueues begs the
question of whether they should be un-initialized. Add the corresponding
cleanup tags in _release_dev to ensure work isn't dispatched after
the private struct is free'd.

Suggested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Fixes: e5f84dbaea59 ("vfio: ccw: return I/O results asynchronously")
Fixes: 3f02cb2fd9d2 ("vfio-ccw: Wire up the CRW irq and CRW region")
Cc: stable@vger.kernel.org
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>

diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 032a1cdf4df7..d361d1fde3a0 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -131,6 +131,13 @@ static void vfio_ccw_mdev_release_dev(struct vfio_device *vdev)
 		container_of(vdev, struct vfio_ccw_private, vdev);
 	struct vfio_ccw_crw *crw, *temp;
 
+	/*
+	 * Ensure these work items are fully drained, so none can
+	 * fire after being released.
+	 */
+	cancel_work_sync(&private->io_work);
+	cancel_work_sync(&private->crw_work);
+
 	list_for_each_entry_safe(crw, temp, &private->crw, next) {
 		list_del(&crw->next);
 		kfree(crw);
@@ -202,6 +209,14 @@ static void vfio_ccw_mdev_close_device(struct vfio_device *vdev)
 		container_of(vdev, struct vfio_ccw_private, vdev);
 
 	vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE);
+
+	/*
+	 * Ensure these work items are drained, in the event the
+	 * device is re-opened instead of released.
+	 */
+	cancel_work_sync(&private->io_work);
+	cancel_work_sync(&private->crw_work);
+
 	vfio_ccw_unregister_dev_regions(private);
 }
 

[PATCH 5.10.y] s390/vfio_ccw: Cancel existing workqueues

[Sasha Levin]

From: Eric Farman <farman@linux.ibm.com>

[ Upstream commit 79c60b2c61105368dcc8444eb45847e21734f7c4 ]

The initialization of the io_work and crw_work workqueues begs the
question of whether they should be un-initialized. Add the corresponding
cleanup tags in _release_dev to ensure work isn't dispatched after
the private struct is free'd.

Suggested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Fixes: e5f84dbaea59 ("vfio: ccw: return I/O results asynchronously")
Fixes: 3f02cb2fd9d2 ("vfio-ccw: Wire up the CRW irq and CRW region")
Cc: stable@vger.kernel.org
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/s390/cio/vfio_ccw_drv.c | 7 +++++++
 drivers/s390/cio/vfio_ccw_ops.c | 8 ++++++++
 2 files changed, 15 insertions(+)

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index e3c1060b6056c..2f080e7281f59 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -241,6 +241,13 @@ static int vfio_ccw_sch_remove(struct subchannel *sch)
 
 	vfio_ccw_sch_quiesce(sch);
 
+	/*
+	 * Ensure these work items are fully drained, so none can
+	 * fire after being released.
+	 */
+	cancel_work_sync(&private->io_work);
+	cancel_work_sync(&private->crw_work);
+
 	list_for_each_entry_safe(crw, temp, &private->crw, next) {
 		list_del(&crw->next);
 		kfree(crw);
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 2280f51dd679d..0d9ac3293fe32 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -204,6 +204,14 @@ static void vfio_ccw_mdev_release(struct mdev_device *mdev)
 	}
 
 	cp_free(&private->cp);
+
+	/*
+	 * Ensure these work items are drained, in the event the
+	 * device is re-opened instead of released.
+	 */
+	cancel_work_sync(&private->io_work);
+	cancel_work_sync(&private->crw_work);
+
 	vfio_ccw_unregister_dev_regions(private);
 	vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
 				 &private->nb);
-- 
2.53.0