From: Franck Jullien <franck.jullien@odyssee-systemes.fr>
Date: Tue, 22 Mar 2016 10:52:22 +0000 (+0100)
Subject: dmaengine: vdma: don't crash when bad channel is requested
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=330ed4da2c8eb821e70b1366a7af53eb1c7421fb;p=linux.git

dmaengine: vdma: don't crash when bad channel is requested

When client request a non existing channel from of_dma_xilinx_xlate
we get a NULL pointer dereferencing. This patch fix this problem.

Signed-off-by: Franck Jullien <franck.jullien@odyssee-systemes.fr>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
---

diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
index 0ee0321868d36..ef67f278e076d 100644
--- a/drivers/dma/xilinx/xilinx_vdma.c
+++ b/drivers/dma/xilinx/xilinx_vdma.c
@@ -1236,7 +1236,7 @@ static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec,
 	struct xilinx_vdma_device *xdev = ofdma->of_dma_data;
 	int chan_id = dma_spec->args[0];
 
-	if (chan_id >= XILINX_VDMA_MAX_CHANS_PER_DEVICE)
+	if (chan_id >= XILINX_VDMA_MAX_CHANS_PER_DEVICE || !xdev->chan[chan_id])
 		return NULL;
 
 	return dma_get_slave_channel(&xdev->chan[chan_id]->common);