On 11/17/25 9:12 AM, Johan Hovold wrote:

Make sure to drop the reference taken when looking up the idxd device as part of the compat bind and unbind sysfs interface.

Fixes: 6e7f3ee97bbe ("dmaengine: idxd: move dsa_drv support to compatible mode") Cc: stable@vger.kernel.org # 5.15 Cc: Dave Jiang dave.jiang@intel.com Signed-off-by: Johan Hovold johan@kernel.org

Reviewed-by: Dave Jiang dave.jiang@intel.com> ---

drivers/dma/idxd/compat.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/idxd/compat.c b/drivers/dma/idxd/compat.c index eff9943f1a42..95b8ef958633 100644 --- a/drivers/dma/idxd/compat.c +++ b/drivers/dma/idxd/compat.c @@ -20,11 +20,16 @@ static ssize_t unbind_store(struct device_driver *drv, const char *buf, size_t c int rc = -ENODEV; dev = bus_find_device_by_name(bus, NULL, buf);

• if (dev && dev->driver) {

• if (!dev)

• return -ENODEV;
  

• if (dev->driver) { device_driver_detach(dev); rc = count; }

• put_device(dev);
• return rc;

} static DRIVER_ATTR_IGNORE_LOCKDEP(unbind, 0200, NULL, unbind_store); @@ -38,9 +43,12 @@ static ssize_t bind_store(struct device_driver *drv, const char *buf, size_t cou struct idxd_dev *idxd_dev; dev = bus_find_device_by_name(bus, NULL, buf);

• if (!dev || dev->driver || drv != &dsa_drv.drv)

• if (!dev) return -ENODEV;

• if (dev->driver || drv != &dsa_drv.drv)

• goto err_put_dev;
  

• idxd_dev = confdev_to_idxd_dev(dev); if (is_idxd_dev(idxd_dev)) { alt_drv = driver_find("idxd", bus);

@@ -53,13 +61,20 @@ static ssize_t bind_store(struct device_driver *drv, const char *buf, size_t cou alt_drv = driver_find("user", bus); } if (!alt_drv)

• return -ENODEV;
  

• goto err_put_dev;
  

rc = device_driver_attach(alt_drv, dev); if (rc < 0)

• return rc;
  

• goto err_put_dev;
  

• put_device(dev);

return count;

+err_put_dev:

• put_device(dev);
• return rc;

} static DRIVER_ATTR_IGNORE_LOCKDEP(bind, 0200, NULL, bind_store);