On Mon, Jan 11, 2021 at 01:00:31PM +0100, Oliver Neukum wrote: > Am Montag, den 11.01.2021, 10:49 +0000 schrieb Bui Quang Minh: > > In mcba_usb_read_bulk_callback(), when we don't resubmit or fails to > > resubmit the urb, we need to deallocate the transfer buffer that is > > allocated in mcba_usb_start(). > > > > Reported-by: syzbot+57281c762a3922e14dfe@xxxxxxxxxxxxxxxxxxxxxxxxx > > Signed-off-by: Bui Quang Minh <minhquangbui99@xxxxxxxxx> > > --- > > v1: add memory leak fix when not resubmitting urb > > v2: add memory leak fix when failing to resubmit urb > > > > drivers/net/can/usb/mcba_usb.c | 11 ++++++++--- > > 1 file changed, 8 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/net/can/usb/mcba_usb.c b/drivers/net/can/usb/mcba_usb.c > > index df54eb7d4b36..30236e640116 100644 > > --- a/drivers/net/can/usb/mcba_usb.c > > +++ b/drivers/net/can/usb/mcba_usb.c > > @@ -584,6 +584,8 @@ static void mcba_usb_read_bulk_callback(struct urb *urb) > > case -EPIPE: > > case -EPROTO: > > case -ESHUTDOWN: > > + usb_free_coherent(urb->dev, urb->transfer_buffer_length, > > + urb->transfer_buffer, urb->transfer_dma); > > return; > > > > Can you call usb_free_coherent() in what can be hard IRQ context? You are right, I digged in the code and saw some comments that on some architectures, usb_free_coherent() cannot be called in hard IRQ context. I see the usb_free_coherent() is called in write_bulk_callback too. I will send a patch that uses usb_anchor to keep track of these urbs and cleanup the transfer buffer later in disconnect(). Thank you for your review, Quang Minh.
