iio: multiplexer: add NULL check on devm_kzalloc() and devm_kmemdup() return values

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@embeddedor.com>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/multiplexer/iio-mux.c b/drivers/iio/multiplexer/iio-mux.c
index 92495d309193856c89a55a82443e304f4a227883..60621ccd67e4feb5b4630b21408fe7b3ed41f46b 100644 (file)
--- a/drivers/iio/multiplexer/iio-mux.c
+++ b/drivers/iio/multiplexer/iio-mux.c
@@ -284,6 +284,9 @@ static int mux_configure_channel(struct device *dev, struct mux *mux,
        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;
 
@@ -308,6 +311,9 @@ static int mux_configure_channel(struct device *dev, struct mux *mux,
 
                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;
        }