[PATCH 6.6 082/254] dmaengine: idxd: fix device leaks on compat bind and unbind
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2026-01-28 15:30:56
Also in:
stable
6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Johan Hovold <johan@kernel.org>
commit 799900f01792cf8b525a44764f065f83fcafd468 upstream.
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>
Link: https://patch.msgid.link/20251117161258.10679-7-johan@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/dma/idxd/compat.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
--- a/drivers/dma/idxd/compat.c
+++ b/drivers/dma/idxd/compat.c@@ -21,11 +21,16 @@ static ssize_t unbind_store(struct devic 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);
@@ -39,9 +44,12 @@ static ssize_t bind_store(struct device_ 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);
@@ -54,13 +62,20 @@ static ssize_t bind_store(struct device_ 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);