This is a note to let you know that I've just added the patch titled s390/ism: add release function for struct device to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: s390-ism-add-release-function-for-struct-device.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 9826d8b5681ea6eed03dab09277bb4d158ff1657 Author: Julian Ruess <julianr@xxxxxxxxxxxxx> Date: Fri Feb 14 13:01:37 2025 +0100 s390/ism: add release function for struct device [ Upstream commit 915e34d5ad35a6a9e56113f852ade4a730fb88f0 ] According to device_release() in /drivers/base/core.c, a device without a release function is a broken device and must be fixed. The current code directly frees the device after calling device_add() without waiting for other kernel parts to release their references. Thus, a reference could still be held to a struct device, e.g., by sysfs, leading to potential use-after-free issues if a proper release function is not set. Fixes: 8c81ba20349d ("net/smc: De-tangle ism and smc device initialization") Reviewed-by: Alexandra Winter <wintera@xxxxxxxxxxxxx> Reviewed-by: Wenjia Zhang <wenjia@xxxxxxxxxxxxx> Signed-off-by: Julian Ruess <julianr@xxxxxxxxxxxxx> Signed-off-by: Alexandra Winter <wintera@xxxxxxxxxxxxx> Reviewed-by: Simon Horman <horms@xxxxxxxxxx> Link: https://patch.msgid.link/20250214120137.563409-1-wintera@xxxxxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/s390/net/ism_drv.c b/drivers/s390/net/ism_drv.c index f6a0626a6b3ec..af0d90beba638 100644 --- a/drivers/s390/net/ism_drv.c +++ b/drivers/s390/net/ism_drv.c @@ -611,6 +611,15 @@ static int ism_dev_init(struct ism_dev *ism) return ret; } +static void ism_dev_release(struct device *dev) +{ + struct ism_dev *ism; + + ism = container_of(dev, struct ism_dev, dev); + + kfree(ism); +} + static int ism_probe(struct pci_dev *pdev, const struct pci_device_id *id) { struct ism_dev *ism; @@ -624,6 +633,7 @@ static int ism_probe(struct pci_dev *pdev, const struct pci_device_id *id) dev_set_drvdata(&pdev->dev, ism); ism->pdev = pdev; ism->dev.parent = &pdev->dev; + ism->dev.release = ism_dev_release; device_initialize(&ism->dev); dev_set_name(&ism->dev, dev_name(&pdev->dev)); ret = device_add(&ism->dev); @@ -660,7 +670,7 @@ static int ism_probe(struct pci_dev *pdev, const struct pci_device_id *id) device_del(&ism->dev); err_dev: dev_set_drvdata(&pdev->dev, NULL); - kfree(ism); + put_device(&ism->dev); return ret; } @@ -706,7 +716,7 @@ static void ism_remove(struct pci_dev *pdev) pci_disable_device(pdev); device_del(&ism->dev); dev_set_drvdata(&pdev->dev, NULL); - kfree(ism); + put_device(&ism->dev); } static struct pci_driver ism_driver = {