staging: rtl8712: error handling refactoring

There was strange error handling logic in case of fw load failure. For
some reason fw loader callback was doing clean up stuff when fw is not
available. I don't see any reason behind doing this. Since this driver
doesn't have EEPROM firmware let's just disconnect it in case of fw load
failure. Doing clean up stuff in 2 different place which can run
concurently is not good idea and syzbot found 2 bugs related to this
strange approach.

So, in this pacth I deleted all clean up code from fw callback and made
a call to device_release_driver() under device_lock(parent) in case of fw
load failure. This approach is more generic and it defend driver from UAF
bugs, since all clean up code is moved to one place.

Fixes: e02a3b9458 ("staging: rtl8712: fix memory leak in rtl871x_load_fw_cb")
Fixes: 8c213fa591 ("staging: r8712u: Use asynchronous firmware loading")
Cc: stable <stable@vger.kernel.org>
Reported-and-tested-by: syzbot+5872a520e0ce0a7c7230@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+cc699626e48a6ebaf295@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Link: https://lore.kernel.org/r/d49ecc56e97c4df181d7bd4d240b031f315eacc3.1626895918.git.paskripkin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Pavel Skripkin 2021-07-21 22:34:47 +03:00 committed by Greg Kroah-Hartman
parent 9be550ee43
commit e9e6aa51b2
2 changed files with 41 additions and 37 deletions

View File

@ -29,21 +29,31 @@
#define FWBUFF_ALIGN_SZ 512
#define MAX_DUMP_FWSZ (48 * 1024)
static void rtl871x_load_fw_fail(struct _adapter *adapter)
{
struct usb_device *udev = adapter->dvobjpriv.pusbdev;
struct device *dev = &udev->dev;
struct device *parent = dev->parent;
complete(&adapter->rtl8712_fw_ready);
dev_err(&udev->dev, "r8712u: Firmware request failed\n");
if (parent)
device_lock(parent);
device_release_driver(dev);
if (parent)
device_unlock(parent);
}
static void rtl871x_load_fw_cb(const struct firmware *firmware, void *context)
{
struct _adapter *adapter = context;
if (!firmware) {
struct usb_device *udev = adapter->dvobjpriv.pusbdev;
struct usb_interface *usb_intf = adapter->pusb_intf;
dev_err(&udev->dev, "r8712u: Firmware request failed\n");
usb_put_dev(udev);
usb_set_intfdata(usb_intf, NULL);
r8712_free_drv_sw(adapter);
adapter->dvobj_deinit(adapter);
complete(&adapter->rtl8712_fw_ready);
free_netdev(adapter->pnetdev);
rtl871x_load_fw_fail(adapter);
return;
}
adapter->fw = firmware;

View File

@ -591,16 +591,11 @@ static void r871xu_dev_remove(struct usb_interface *pusb_intf)
{
struct net_device *pnetdev = usb_get_intfdata(pusb_intf);
struct usb_device *udev = interface_to_usbdev(pusb_intf);
if (pnetdev) {
struct _adapter *padapter = netdev_priv(pnetdev);
/* never exit with a firmware callback pending */
wait_for_completion(&padapter->rtl8712_fw_ready);
pnetdev = usb_get_intfdata(pusb_intf);
usb_set_intfdata(pusb_intf, NULL);
if (!pnetdev)
goto firmware_load_fail;
release_firmware(padapter->fw);
if (drvpriv.drv_registered)
padapter->surprise_removed = true;
@ -619,8 +614,7 @@ static void r871xu_dev_remove(struct usb_interface *pusb_intf)
* when disconnect
*/
usb_put_dev(udev);
}
firmware_load_fail:
/* If we didn't unplug usb dongle and remove/insert module, driver
* fails on sitesurvey for the first time when device is up.
* Reset usb port for sitesurvey fail issue.