[PATCH 4.4 67/80] ASoC: sirf: Fix potential NULL pointer dereference

From: Greg Kroah-Hartman
Date: Mon Sep 03 2018 - 13:03:12 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>

commit ae1c696a480c67c45fb23b35162183f72c6be0e1 upstream.

There is a potential execution path in which function
platform_get_resource() returns NULL. If this happens,
we will end up having a NULL pointer dereference.

Fix this by replacing devm_ioremap with devm_ioremap_resource,
which has the NULL check and the memory region request.

This code was detected with the help of Coccinelle.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 2bd8d1d5cf89 ("ASoC: sirf: Add audio usp interface driver")
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
sound/soc/sirf/sirf-usp.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

--- a/sound/soc/sirf/sirf-usp.c
+++ b/sound/soc/sirf/sirf-usp.c
@@ -367,10 +367,9 @@ static int sirf_usp_pcm_probe(struct pla
platform_set_drvdata(pdev, usp);

mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- base = devm_ioremap(&pdev->dev, mem_res->start,
- resource_size(mem_res));
- if (base == NULL)
- return -ENOMEM;
+ base = devm_ioremap_resource(&pdev->dev, mem_res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
usp->regmap = devm_regmap_init_mmio(&pdev->dev, base,
&sirf_usp_regmap_config);
if (IS_ERR(usp->regmap))