6.12-stable review patch. If anyone has any objections, please let me know.
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From: Julian Ruess julianr@linux.ibm.com
[ 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@linux.ibm.com Reviewed-by: Wenjia Zhang wenjia@linux.ibm.com Signed-off-by: Julian Ruess julianr@linux.ibm.com Signed-off-by: Alexandra Winter wintera@linux.ibm.com Reviewed-by: Simon Horman horms@kernel.org Link: https://patch.msgid.link/20250214120137.563409-1-wintera@linux.ibm.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/s390/net/ism_drv.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/s390/net/ism_drv.c b/drivers/s390/net/ism_drv.c index e36e3ea165d3b..2f34761e64135 100644 --- a/drivers/s390/net/ism_drv.c +++ b/drivers/s390/net/ism_drv.c @@ -588,6 +588,15 @@ 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; @@ -601,6 +610,7 @@ 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); @@ -637,7 +647,7 @@ 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; } @@ -682,7 +692,7 @@ 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 = {