6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Julian Ruess <julianr@xxxxxxxxxxxxx>
[ 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>
---
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 = {
--
2.39.5
