From 0c97ff108f825a70c3bb29d65ddf0a013d231bb9 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 17 Nov 2025 17:12:48 +0100 Subject: [PATCH] dmaengine: idxd: fix device leaks on compat bind and unbind 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 Signed-off-by: Johan Hovold Link: https://patch.msgid.link/20251117161258.10679-7-johan@kernel.org Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- 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 a4adb0c179959..5d7aca2299b30 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); -- 2.47.3