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can: mcba_usb_start(): add missing urb->transfer_dma initialization

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Yasushi reported, that his Microchip CAN Analyzer stopped working
since commit 91c0255717 ("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 archive 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 initialize 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.

| DMAR: [DMA Write] Request device [00:14.0] PASID ffffffff fault addr 0 [fault reason 05] PTE Write access is not set

Fixes: 91c0255717 ("can: mcba_usb: fix memory leak in mcba_usb")
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=990850
Link: https://lore.kernel.org/r/20210725103630.23864-1-paskripkin@gmail.com
Cc: linux-stable <stable@vger.kernel.org>
Reported-by: Yasushi SHOJI <yasushi.shoji@gmail.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Tested-by: Yasushi SHOJI <yashi@spacecubics.com>
[mkl: fixed typos in commit message - thanks Yasushi SHOJI]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Pavel Skripkin 2021-07-25 13:36:30 +03:00 committed by Marc Kleine-Budde
parent f6b3c7848e
commit fc43fb69a7
1 changed files with 2 additions and 0 deletions
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2
drivers/net/can/usb/mcba_usb.c
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@ -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,