ata: pata_pxa: Fix potential NULL pointer dereference in pxa_ata_probe()

devm_ioremap() returns NULL on error. Currently, pxa_ata_probe() does
not check for this case, which can result in a NULL pointer dereference.

Add NULL check after devm_ioremap() to prevent this issue.

Fixes: 2dc6c6f15da9 ("[ARM] pata_pxa: DMA-capable PATA driver")
Signed-off-by: Henry Martin <[e-mail]>
Signed-off-by: Damien Le Moal <[e-mail]>

drivers/ata/pata_pxa.c

···
 
 	ap->ioaddr.cmd_addr	= devm_ioremap(&pdev->dev, cmd_res->start,
 						resource_size(cmd_res));
+	if (!ap->ioaddr.cmd_addr)
+		return -ENOMEM;
 	ap->ioaddr.ctl_addr	= devm_ioremap(&pdev->dev, ctl_res->start,
 						resource_size(ctl_res));
+	if (!ap->ioaddr.ctl_addr)
+		return -ENOMEM;
 	ap->ioaddr.bmdma_addr	= devm_ioremap(&pdev->dev, dma_res->start,
 						resource_size(dma_res));
+	if (!ap->ioaddr.bmdma_addr)
+		return -ENOMEM;
 
 	/*
 	 * Adjust register offsets