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@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=feb045d335c1fdde5bf7 Signed-off-by: Zqiang <qiang.zhang1211@xxxxxxxxx> --- drivers/usb/gadget/legacy/raw_gadget.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/usb/gadget/legacy/raw_gadget.c b/drivers/usb/gadget/legacy/raw_gadget.c index 2acece16b890..e549022642e5 100644 --- 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; } -- 2.17.1
