3.2.84-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
commit 4fdef698383db07d829da567e0e405fc41ff3a89 upstream.
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")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/usb/renesas_usbhs/fifo.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
--- a/drivers/usb/renesas_usbhs/fifo.c
+++ b/drivers/usb/renesas_usbhs/fifo.c
@@ -760,15 +760,22 @@ static void usbhsf_dma_prepare_tasklet(u
{
struct usbhs_pkt *pkt = (struct usbhs_pkt *)data;
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 scatterlist sg;
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_data_direction dir;
dma_cookie_t cookie;
+ 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_FROM_DEVICE : DMA_TO_DEVICE;
sg_init_table(&sg, 1);
@@ -781,7 +788,7 @@ static void usbhsf_dma_prepare_tasklet(u
DMA_PREP_INTERRUPT |
DMA_CTRL_ACK);
if (!desc)
- return;
+ goto xfer_work_end;
desc->callback = usbhsf_dma_complete;
desc->callback_param = pipe;
@@ -789,7 +796,7 @@ static void usbhsf_dma_prepare_tasklet(u
cookie = desc->tx_submit(desc);
if (cookie < 0) {
dev_err(dev, "Failed to submit dma descriptor\n");
- return;
+ goto xfer_work_end;
}
dev_dbg(dev, " %s %d (%d/ %d)\n",
@@ -797,6 +804,9 @@ static void usbhsf_dma_prepare_tasklet(u
usbhsf_dma_start(pipe, fifo);
dma_async_issue_pending(chan);
+
+xfer_work_end:
+ usbhs_unlock(priv, flags);
}
/*
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