[PATCH v6 15/15] dmaengine: dw-edma: Add pcim_iomap_table return check

[Gustavo Pimentel <Gustavo.Pimentel@xxxxxxxxxxxx>]

Currently, is missing a null check on a pcim_iomap_table() return value
and this can lead to a null pointer dereference if the desired BAR
wasn't mapped previously.
Fix this by adding a null check and returning -ENOMEM.

Addresses-Coverity: ("Dereference null return")
Signed-off-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
---
 drivers/dma/dw-edma/dw-edma-pcie.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
index 502de71..70d0d08 100644
--- a/drivers/dma/dw-edma/dw-edma-pcie.c
+++ b/drivers/dma/dw-edma/dw-edma-pcie.c
@@ -238,6 +238,9 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
 	dw->rd_ch_cnt = vsec_data.rd_ch_cnt;
 
 	dw->rg_region.vaddr = pcim_iomap_table(pdev)[vsec_data.rg.bar];
+	if (!dw->rg_region.vaddr)
+		return -ENOMEM;
+
 	dw->rg_region.vaddr += vsec_data.rg.off;
 	dw->rg_region.paddr = pdev->resource[vsec_data.rg.bar].start;
 	dw->rg_region.paddr += vsec_data.rg.off;
@@ -250,12 +253,18 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
 		struct dw_edma_block *dt_block = &vsec_data.dt_wr[i];
 
 		ll_region->vaddr = pcim_iomap_table(pdev)[ll_block->bar];
+		if (!ll_region->vaddr)
+			return -ENOMEM;
+
 		ll_region->vaddr += ll_block->off;
 		ll_region->paddr = pdev->resource[ll_block->bar].start;
 		ll_region->paddr += ll_block->off;
 		ll_region->sz = ll_block->sz;
 
 		dt_region->vaddr = pcim_iomap_table(pdev)[dt_block->bar];
+		if (!dt_region->vaddr)
+			return -ENOMEM;
+
 		dt_region->vaddr += dt_block->off;
 		dt_region->paddr = pdev->resource[dt_block->bar].start;
 		dt_region->paddr += dt_block->off;
@@ -269,12 +278,18 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
 		struct dw_edma_block *dt_block = &vsec_data.dt_rd[i];
 
 		ll_region->vaddr = pcim_iomap_table(pdev)[ll_block->bar];
+		if (!ll_region->vaddr)
+			return -ENOMEM;
+
 		ll_region->vaddr += ll_block->off;
 		ll_region->paddr = pdev->resource[ll_block->bar].start;
 		ll_region->paddr += ll_block->off;
 		ll_region->sz = ll_block->sz;
 
 		dt_region->vaddr = pcim_iomap_table(pdev)[dt_block->bar];
+		if (!dt_region->vaddr)
+			return -ENOMEM;
+
 		dt_region->vaddr += dt_block->off;
 		dt_region->paddr = pdev->resource[dt_block->bar].start;
 		dt_region->paddr += dt_block->off;
-- 
2.7.4