Messages in this thread Patch in this message | | | From | Pavel Skripkin <> | Subject | [PATCH] net: can: add missing urb->transfer_dma initialization | Date | Sun, 25 Jul 2021 13:36:30 +0300 |
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Yasushi reported, that his Microchip CAN Analyzer stopped working since commit 91c02557174b ("can: mcba_usb: fix memory leak in mcba_usb"). The problem was in missing urb->transfer_dma initialization.
In my previous patch to this driver I refactored mcba_usb_start() code to avoid leaking usb coherent buffers. To achive it, I passed local stack variable to usb_alloc_coherent() and then saved it to private array to correctly free all coherent buffers on ->close() call. But I forgot to inialize urb->transfer_dma with variable passed to usb_alloc_coherent().
All of this was causing device to not work, since dma addr 0 is not valid and following log can be found on bug report page, which points exactly to problem described above.
[ 33.862175] DMAR: [DMA Write] Request device [00:14.0] PASID ffffffff fault addr 0 [fault reason 05] PTE Write access is not set
Bug report: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=990850
Reported-by: Yasushi SHOJI <yasushi.shoji@gmail.com> Fixes: 91c02557174b ("can: mcba_usb: fix memory leak in mcba_usb") Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> --- drivers/net/can/usb/mcba_usb.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/net/can/usb/mcba_usb.c b/drivers/net/can/usb/mcba_usb.c index a45865bd7254..a1a154c08b7f 100644 --- a/drivers/net/can/usb/mcba_usb.c +++ b/drivers/net/can/usb/mcba_usb.c @@ -653,6 +653,8 @@ static int mcba_usb_start(struct mcba_priv *priv) break; } + urb->transfer_dma = buf_dma; + usb_fill_bulk_urb(urb, priv->udev, usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_IN), buf, MCBA_USB_RX_BUFF_SIZE, -- 2.32.0
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