[PATCH 4.14 63/75] iio: multiplexer: add NULL check on devm_kzalloc() and devm_kmemdup() return values

[Greg Kroah-Hartman]

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

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

From: "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx>


[ Upstream commit dd92d5ea20ef8a42be7aeda08c669c586c730451 ]

Check return values from call to devm_kzalloc() and devm_kmemup()
in order to prevent a NULL pointer dereference.

This issue was detected using Coccinelle and the following semantic patch:

@@
expression x;
identifier fld;
@@

* x = devm_kzalloc(...);
   ... when != x == NULL
   x->fld

Fixes: 7ba9df54b091 ("iio: multiplexer: new iio category and iio-mux driver")
Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
Acked-by: Peter Rosin <peda@xxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/iio/multiplexer/iio-mux.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/iio/multiplexer/iio-mux.c
+++ b/drivers/iio/multiplexer/iio-mux.c
@@ -285,6 +285,9 @@ static int mux_configure_channel(struct
 	child->ext_info_cache = devm_kzalloc(dev,
 					     sizeof(*child->ext_info_cache) *
 					     num_ext_info, GFP_KERNEL);
+	if (!child->ext_info_cache)
+		return -ENOMEM;
+
 	for (i = 0; i < num_ext_info; ++i) {
 		child->ext_info_cache[i].size = -1;
 
@@ -309,6 +312,9 @@ static int mux_configure_channel(struct
 
 		child->ext_info_cache[i].data = devm_kmemdup(dev, page, ret + 1,
 							     GFP_KERNEL);
+		if (!child->ext_info_cache[i].data)
+			return -ENOMEM;
+
 		child->ext_info_cache[i].data[ret] = 0;
 		child->ext_info_cache[i].size = ret;
 	}