On Fri, 2022-11-11 at 22:54 +0800, Yang Yingliang wrote:
If device_register() fails in cxl_pci_afu|adapter(), the device
is not added, device_unregister() can not be called in the error
path, otherwise it will cause a null-ptr-deref because of removing
not added device.
As comment of device_register() says, it should use put_device() to
give
up the reference in the error path. So split device_unregister() into
device_del() and put_device(), then goes to put dev when register
fails.
Fixes: f204e0b8cedd ("cxl: Driver code for powernv PCIe based cards
for userspace access")
Signed-off-by: Yang Yingliang <redacted>
See reply to patch #1.
This patch puts a few things between the device_del() call and the
put_device() call, but that looks fine - we don't touch afu->dev in the
middle.
Thanks for the fix!
Acked-by: Andrew Donnellan <redacted>
quoted hunk ↗ jump to hunk
---
drivers/misc/cxl/pci.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 3de0aea62ade..6d495d641c95 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -1164,10 +1164,10 @@ static int pci_init_afu(struct cxl *adapter,
int slice, struct pci_dev *dev)
* if it returns an error!
*/
if ((rc = cxl_register_afu(afu)))
- goto err_put1;
+ goto err_put_dev;
if ((rc = cxl_sysfs_afu_add(afu)))
- goto err_put1;
+ goto err_del_dev;
adapter->afu[afu->slice] = afu;
@@ -1176,10 +1176,12 @@ static int pci_init_afu(struct cxl *adapter,
int slice, struct pci_dev *dev)
return 0;
-err_put1:
+err_del_dev:
+ device_del(&afu->dev);
+err_put_dev:
pci_deconfigure_afu(afu);
cxl_debugfs_afu_remove(afu);
- device_unregister(&afu->dev);
+ put_device(&afu->dev);
return rc;
err_free_native:
@@ -1667,23 +1669,25 @@ static struct cxl
*cxl_pci_init_adapter(struct pci_dev *dev)
* even if it returns an error!
*/
if ((rc = cxl_register_adapter(adapter)))
- goto err_put1;
+ goto err_put_dev;
if ((rc = cxl_sysfs_adapter_add(adapter)))
- goto err_put1;
+ goto err_del_dev;
/* Release the context lock as adapter is configured */
cxl_adapter_context_unlock(adapter);
return adapter;
-err_put1:
+err_del_dev:
+ device_del(&adapter->dev);
+err_put_dev:
/* This should mirror cxl_remove_adapter, except without the
* sysfs parts
*/
cxl_debugfs_adapter_remove(adapter);
cxl_deconfigure_adapter(adapter);
- device_unregister(&adapter->dev);
+ put_device(&adapter->dev);
return ERR_PTR(rc);
err_release:
--
Andrew Donnellan OzLabs, ADL Canberra
ajd@linux.ibm.com IBM Australia Limited