From: Shravya Kumbham <shravya.kumbham@xxxxxxxxxx>
In zynqmp_dma_alloc/free_chan_resources functions there is a
potential overflow in the below expressions.
dma_alloc_coherent(chan->dev, (2 * chan->desc_size *
ZYNQMP_DMA_NUM_DESCS),
&chan->desc_pool_p, GFP_KERNEL);
dma_free_coherent(chan->dev,(2 * ZYNQMP_DMA_DESC_SIZE(chan) *
ZYNQMP_DMA_NUM_DESCS),
chan->desc_pool_v, chan->desc_pool_p);
The arguments desc_size and ZYNQMP_DMA_NUM_DESCS are 32 bit. Though
this overflow condition is not observed but it is a potential problem
in the case of 32-bit multiplication. Hence fix it by using typecast.
Addresses-Coverity: Event overflow_before_widen.
Signed-off-by: Shravya Kumbham <shravya.kumbham@xxxxxxxxxx>
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xxxxxxxxxx>
---
drivers/dma/xilinx/zynqmp_dma.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c
index 5fecf5aa6e85..2d0eba25739d 100644
--- a/drivers/dma/xilinx/zynqmp_dma.c
+++ b/drivers/dma/xilinx/zynqmp_dma.c
@@ -490,7 +490,8 @@ static int zynqmp_dma_alloc_chan_resources(struct dma_chan *dchan)
}
chan->desc_pool_v = dma_alloc_coherent(chan->dev,
- (2 * chan->desc_size * ZYNQMP_DMA_NUM_DESCS),
+ ((size_t)(2 * chan->desc_size) *
+ ZYNQMP_DMA_NUM_DESCS),
&chan->desc_pool_p, GFP_KERNEL);
if (!chan->desc_pool_v)
return -ENOMEM;
@@ -677,7 +678,8 @@ static void zynqmp_dma_free_chan_resources(struct dma_chan *dchan)
zynqmp_dma_free_descriptors(chan);
spin_unlock_irqrestore(&chan->lock, irqflags);
dma_free_coherent(chan->dev,
- (2 * ZYNQMP_DMA_DESC_SIZE(chan) * ZYNQMP_DMA_NUM_DESCS),
+ ((size_t)(2 * ZYNQMP_DMA_DESC_SIZE(chan)) *
+ ZYNQMP_DMA_NUM_DESCS),
chan->desc_pool_v, chan->desc_pool_p);
kfree(chan->sw_desc_pool);
pm_runtime_mark_last_busy(chan->dev);
--
2.17.1
