This is a note to let you know that I've just added the patch titled
cxl: fix possible null-ptr-deref in cxl_pci_init_afu|adapter()
to the 4.19-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:
cxl-fix-possible-null-ptr-deref-in-cxl_pci_init_afu-.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 99d66e4b1e774c6ea337efb96f922189017544c0
Author: Yang Yingliang <yangyingliang@xxxxxxxxxx>
Date: Fri Nov 11 22:54:40 2022 +0800
cxl: fix possible null-ptr-deref in cxl_pci_init_afu|adapter()
[ Upstream commit 02cd3032b154fa02fdf90e7467abaeed889330b2 ]
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 <yangyingliang@xxxxxxxxxx>
Acked-by: Frederic Barrat <fbarrat@xxxxxxxxxxxxx>
Acked-by: Andrew Donnellan <ajd@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221111145440.2426970-2-yangyingliang@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index b9d3c87e9318..acb4a339f5fe 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -1168,10 +1168,10 @@ 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;
@@ -1180,10 +1180,12 @@ 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:
@@ -1671,23 +1673,25 @@ 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:
