iio: dummy: iio_simple_dummy: check the return value of kstrdup()

stable inclusion
from stable-v5.10.122
commit 8caa4b7d411c429e5beed7952d9c5af8ee2ac68c
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5W6OE

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8caa4b7d411c429e5beed7952d9c5af8ee2ac68c

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

[ Upstream commit ba936421 ]

kstrdup() is also a memory allocation-related function, it returns NULL
when some memory errors happen. So it is better to check the return
value of it so to catch the memory error in time. Besides, there should
have a kfree() to clear up the allocation if we get a failure later in
this function to prevent memory leak.
Signed-off-by: NXiaoke Wang <xkernel.wang@foxmail.com>
Link: https://lore.kernel.org/r/tencent_C920CFCC33B9CC1C63141FE1334A39FF8508@qq.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>

drivers/iio/dummy/iio_simple_dummy.c

@@ -575,10 +575,9 @@ static struct iio_sw_device *iio_dummy_probe(const char *name)
 	 */
 
 	swd = kzalloc(sizeof(*swd), GFP_KERNEL);
-	if (!swd) {
-		ret = -ENOMEM;
-		goto error_kzalloc;
-	}
+	if (!swd)
+		return ERR_PTR(-ENOMEM);
+
 	/*
 	 * Allocate an IIO device.
 	 *
@@ -590,7 +589,7 @@ static struct iio_sw_device *iio_dummy_probe(const char *name)
 	indio_dev = iio_device_alloc(parent, sizeof(*st));
 	if (!indio_dev) {
 		ret = -ENOMEM;
-		goto error_ret;
+		goto error_free_swd;
 	}
 
 	st = iio_priv(indio_dev);
@@ -616,6 +615,10 @@ static struct iio_sw_device *iio_dummy_probe(const char *name)
 	 *    indio_dev->name = spi_get_device_id(spi)->name;
 	 */
 	indio_dev->name = kstrdup(name, GFP_KERNEL);
+	if (!indio_dev->name) {
+		ret = -ENOMEM;
+		goto error_free_device;
+	}
 
 	/* Provide description of available channels */
 	indio_dev->channels = iio_dummy_channels;
@@ -632,7 +635,7 @@ static struct iio_sw_device *iio_dummy_probe(const char *name)
 
 	ret = iio_simple_dummy_events_register(indio_dev);
 	if (ret < 0)
-		goto error_free_device;
+		goto error_free_name;
 
 	ret = iio_simple_dummy_configure_buffer(indio_dev);
 	if (ret < 0)
@@ -649,11 +652,12 @@ static struct iio_sw_device *iio_dummy_probe(const char *name)
 	iio_simple_dummy_unconfigure_buffer(indio_dev);
 error_unregister_events:
 	iio_simple_dummy_events_unregister(indio_dev);
+error_free_name:
+	kfree(indio_dev->name);
 error_free_device:
 	iio_device_free(indio_dev);
-error_ret:
+error_free_swd:
 	kfree(swd);
-error_kzalloc:
 	return ERR_PTR(ret);
 }