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usb: renesas_usbhs: fix NULL pointer dereference in xfer_work()

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This patch fixes an issue that the xfer_work() is possible to cause
NULL pointer dereference if the usb cable is disconnected while data
transfer is running.

In such case, a gadget driver may call usb_ep_disable()) before
xfer_work() is actually called. In this case, the usbhs_pkt_pop()
will call usbhsf_fifo_unselect(), and then usbhs_pipe_to_fifo()
in xfer_work() will return NULL.

Fixes: e73a989 ("usb: renesas_usbhs: add DMAEngine support")
Cc: <stable@vger.kernel.org> # v3.1+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Yoshihiro Shimoda 2016-06-08 16:32:49 +09:00 committed by Felipe Balbi
parent 44963d649d
commit 4fdef69838
1 changed files with 14 additions and 4 deletions
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18
drivers/usb/renesas_usbhs/fifo.c
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@ -810,20 +810,27 @@ static void xfer_work(struct work_struct *work)
{
struct usbhs_pkt *pkt = container_of(work, struct usbhs_pkt, work);
struct usbhs_pipe *pipe = pkt->pipe;
struct usbhs_fifo *fifo = usbhs_pipe_to_fifo(pipe);
struct usbhs_fifo *fifo;
struct usbhs_priv *priv = usbhs_pipe_to_priv(pipe);
struct dma_async_tx_descriptor *desc;
struct dma_chan *chan = usbhsf_dma_chan_get(fifo, pkt);
struct dma_chan *chan;
struct device *dev = usbhs_priv_to_dev(priv);
enum dma_transfer_direction dir;
unsigned long flags;
usbhs_lock(priv, flags);
fifo = usbhs_pipe_to_fifo(pipe);
if (!fifo)
goto xfer_work_end;
chan = usbhsf_dma_chan_get(fifo, pkt);
dir = usbhs_pipe_is_dir_in(pipe) ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV;
desc = dmaengine_prep_slave_single(chan, pkt->dma + pkt->actual,
pkt->trans, dir,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc)
return;
goto xfer_work_end;
desc->callback = usbhsf_dma_complete;
desc->callback_param = pipe;
@ -831,7 +838,7 @@ static void xfer_work(struct work_struct *work)
pkt->cookie = dmaengine_submit(desc);
if (pkt->cookie < 0) {
dev_err(dev, "Failed to submit dma descriptor\n");
return;
goto xfer_work_end;
}
dev_dbg(dev, " %s %d (%d/ %d)\n",
@ -842,6 +849,9 @@ static void xfer_work(struct work_struct *work)
usbhs_pipe_set_trans_count_if_bulk(pipe, pkt->trans);
dma_async_issue_pending(chan);
usbhs_pipe_enable(pipe);
xfer_work_end:
usbhs_unlock(priv, flags);
}
/*