USB: gadget: Fix the memory leak in raw_gadget driver

Currently, increasing raw_dev->count happens before invoke the
raw_queue_event(), if the raw_queue_event() return error, invoke
raw_release() will not trigger the dev_free() to be called.

[  268.905865][ T5067] raw-gadget.0 gadget.0: failed to queue event
[  268.912053][ T5067] udc dummy_udc.0: failed to start USB Raw Gadget: -12
[  268.918885][ T5067] raw-gadget.0: probe of gadget.0 failed with error -12
[  268.925956][ T5067] UDC core: USB Raw Gadget: couldn't find an available UDC or it's busy
[  268.934657][ T5067] misc raw-gadget: fail, usb_gadget_register_driver returned -16

BUG: memory leak

[<ffffffff8154bf94>] kmalloc_trace+0x24/0x90 mm/slab_common.c:1076
[<ffffffff8347eb55>] kmalloc include/linux/slab.h:582 [inline]
[<ffffffff8347eb55>] kzalloc include/linux/slab.h:703 [inline]
[<ffffffff8347eb55>] dev_new drivers/usb/gadget/legacy/raw_gadget.c:191 [inline]
[<ffffffff8347eb55>] raw_open+0x45/0x110 drivers/usb/gadget/legacy/raw_gadget.c:385
[<ffffffff827d1d09>] misc_open+0x1a9/0x1f0 drivers/char/misc.c:165

[<ffffffff8154bf94>] kmalloc_trace+0x24/0x90 mm/slab_common.c:1076
[<ffffffff8347cd2f>] kmalloc include/linux/slab.h:582 [inline]
[<ffffffff8347cd2f>] raw_ioctl_init+0xdf/0x410 drivers/usb/gadget/legacy/raw_gadget.c:460
[<ffffffff8347dfe9>] raw_ioctl+0x5f9/0x1120 drivers/usb/gadget/legacy/raw_gadget.c:1250
[<ffffffff81685173>] vfs_ioctl fs/ioctl.c:51 [inline]

[<ffffffff8154bf94>] kmalloc_trace+0x24/0x90 mm/slab_common.c:1076
[<ffffffff833ecc6a>] kmalloc include/linux/slab.h:582 [inline]
[<ffffffff833ecc6a>] kzalloc include/linux/slab.h:703 [inline]
[<ffffffff833ecc6a>] dummy_alloc_request+0x5a/0xe0 drivers/usb/gadget/udc/dummy_hcd.c:665
[<ffffffff833e9132>] usb_ep_alloc_request+0x22/0xd0 drivers/usb/gadget/udc/core.c:196
[<ffffffff8347f13d>] gadget_bind+0x6d/0x370 drivers/usb/gadget/legacy/raw_gadget.c:292

This commit therefore invoke kref_get() under the condition that
raw_queue_event() return success.

Reported-by: syzbot+feb045d335c1fdde5bf7@syzkaller.appspotmail.com
Cc: stable <stable@kernel.org>
Closes: https://syzkaller.appspot.com/bug?extid=feb045d335c1fdde5bf7
Signed-off-by: Zqiang <qiang.zhang1211@gmail.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20230714074011.20989-1-qiang.zhang1211@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/legacy/raw_gadget.c b/drivers/usb/gadget/legacy/raw_gadget.c
index 2acece16b8900ee55647a67fb8d984ceb0dddf7a..e549022642e569e0b505800eab1417d9bca0472a 100644 (file)
--- a/drivers/usb/gadget/legacy/raw_gadget.c
+++ b/drivers/usb/gadget/legacy/raw_gadget.c
@@ -310,13 +310,15 @@ static int gadget_bind(struct usb_gadget *gadget,
        dev->eps_num = i;
        spin_unlock_irqrestore(&dev->lock, flags);
 
-       /* Matches kref_put() in gadget_unbind(). */
-       kref_get(&dev->count);
-
        ret = raw_queue_event(dev, USB_RAW_EVENT_CONNECT, 0, NULL);
-       if (ret < 0)
+       if (ret < 0) {
                dev_err(&gadget->dev, "failed to queue event\n");
+               set_gadget_data(gadget, NULL);
+               return ret;
+       }
 
+       /* Matches kref_put() in gadget_unbind(). */
+       kref_get(&dev->count);
        return ret;
 }