4.14-stable review patch. If anyone has any objections, please let me know.
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From: Alan Stern stern@rowland.harvard.edu
commit 7ae2c3c280db183ca9ada2675c34ec2f7378abfa upstream.
The error-handling pathways in usb_add_gadget_udc_release() are messed up. Aside from the uninformative statement labels, they can deallocate the udc structure after calling put_device(), which is a double-free. This was observed by KASAN in automatic testing.
This patch cleans up the routine. It preserves the requirement that when any failure occurs, we call put_device(&gadget->dev).
Signed-off-by: Alan Stern stern@rowland.harvard.edu Reported-by: Fengguang Wu fengguang.wu@intel.com Reviewed-by: Peter Chen peter.chen@nxp.com Acked-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/gadget/udc/core.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-)
--- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -1158,11 +1158,7 @@ int usb_add_gadget_udc_release(struct de
udc = kzalloc(sizeof(*udc), GFP_KERNEL); if (!udc) - goto err1; - - ret = device_add(&gadget->dev); - if (ret) - goto err2; + goto err_put_gadget;
device_initialize(&udc->dev); udc->dev.release = usb_udc_release; @@ -1171,7 +1167,11 @@ int usb_add_gadget_udc_release(struct de udc->dev.parent = parent; ret = dev_set_name(&udc->dev, "%s", kobject_name(&parent->kobj)); if (ret) - goto err3; + goto err_put_udc; + + ret = device_add(&gadget->dev); + if (ret) + goto err_put_udc;
udc->gadget = gadget; gadget->udc = udc; @@ -1181,7 +1181,7 @@ int usb_add_gadget_udc_release(struct de
ret = device_add(&udc->dev); if (ret) - goto err4; + goto err_unlist_udc;
usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED); udc->vbus = true; @@ -1189,27 +1189,25 @@ int usb_add_gadget_udc_release(struct de /* pick up one of pending gadget drivers */ ret = check_pending_gadget_drivers(udc); if (ret) - goto err5; + goto err_del_udc;
mutex_unlock(&udc_lock);
return 0;
-err5: + err_del_udc: device_del(&udc->dev);
-err4: + err_unlist_udc: list_del(&udc->list); mutex_unlock(&udc_lock);
-err3: - put_device(&udc->dev); device_del(&gadget->dev);
-err2: - kfree(udc); + err_put_udc: + put_device(&udc->dev);
-err1: + err_put_gadget: put_device(&gadget->dev); return ret; }