[PATCH v2] i2c: busses: i2c-pxa.c: Fix for possible null pointer dereferenc

From: Rickard Strandqvist
Date: Sun Jun 29 2014 - 19:27:50 EST


Fix for possible null pointer dereferenc, and there is a risk for memory leak in when something unexpected happens and the function returns.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@xxxxxxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-pxa.c | 37 ++++++++++++++++---------------------
1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index be671f7..886877a 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -1141,10 +1141,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
struct resource *res = NULL;
int ret, irq;

- i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
+ i2c = devm_kzalloc(&dev->dev, sizeof(struct pxa_i2c), GFP_KERNEL);
if (!i2c) {
ret = -ENOMEM;
- goto emalloc;
+ goto err_nothing_to_release;
}

/* Default adapter num to device id; i2c_pxa_probe_dt can override. */
@@ -1154,18 +1154,19 @@ static int i2c_pxa_probe(struct platform_device *dev)
if (ret > 0)
ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type);
if (ret < 0)
- goto eclk;
+ goto err_nothing_to_release;

res = platform_get_resource(dev, IORESOURCE_MEM, 0);
irq = platform_get_irq(dev, 0);
if (res == NULL || irq < 0) {
ret = -ENODEV;
- goto eclk;
+ goto err_nothing_to_release;
}

- if (!request_mem_region(res->start, resource_size(res), res->name)) {
+ if (!devm_request_mem_region(&dev->dev, res->start,
+ resource_size(res), res->name)) {
ret = -ENOMEM;
- goto eclk;
+ goto emalloc;
}

i2c->adap.owner = THIS_MODULE;
@@ -1176,16 +1177,16 @@ static int i2c_pxa_probe(struct platform_device *dev)

strlcpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name));

- i2c->clk = clk_get(&dev->dev, NULL);
+ i2c->clk = devm_clk_get(&dev->dev, NULL);
if (IS_ERR(i2c->clk)) {
ret = PTR_ERR(i2c->clk);
- goto eclk;
+ goto emalloc;
}

- i2c->reg_base = ioremap(res->start, resource_size(res));
- if (!i2c->reg_base) {
+ i2c->reg_base = devm_ioremap(&dev->dev, res->start, resource_size(res));
+ if (IS_ERR(i2c->reg_base)) {
ret = -EIO;
- goto eremap;
+ goto emalloc;
}

i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
@@ -1227,10 +1228,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
i2c->adap.algo = &i2c_pxa_pio_algorithm;
} else {
i2c->adap.algo = &i2c_pxa_algorithm;
- ret = request_irq(irq, i2c_pxa_handler, IRQF_SHARED,
- dev_name(&dev->dev), i2c);
+ ret = devm_request_irq(&dev->dev, irq, i2c_pxa_handler,
+ IRQF_SHARED, dev_name(&dev->dev), i2c);
if (ret)
- goto ereqirq;
+ goto emalloc;
}

i2c_pxa_reset(i2c);
@@ -1261,15 +1262,9 @@ static int i2c_pxa_probe(struct platform_device *dev)
eadapt:
if (!i2c->use_pio)
free_irq(irq, i2c);
-ereqirq:
- clk_disable_unprepare(i2c->clk);
- iounmap(i2c->reg_base);
-eremap:
- clk_put(i2c->clk);
-eclk:
- kfree(i2c);
emalloc:
release_mem_region(res->start, resource_size(res));
+err_nothing_to_release:
return ret;
}

--
1.7.10.4

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