Message ID | 20221111145440.2426970-2-yangyingliang@huawei.com (mailing list archive) |
---|---|
State | Accepted |
Commit | 8bf03f557d6c6e108cf47bea32f4a68e276e1157 |
Headers | show |
Series | [1/2] cxl: fix possible null-ptr-deref in cxl_guest_init_afu|adapter() | expand |
On 11/11/2022 15:54, 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 <yangyingliang@huawei.com> > --- Acked-by: Frederic Barrat <fbarrat@linux.ibm.com> Fred > 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:
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 <yangyingliang@huawei.com> 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 <ajd@linux.ibm.com> > --- > 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:
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:
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@huawei.com> --- drivers/misc/cxl/pci.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)