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

From: Gustavo A. R. Silva
Date: Fri Jul 07 2017 - 00:53:19 EST


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

Cc: Peter Rosin <peda@xxxxxxxxxx>
Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
---
Changes in v2:
Add NULL check on devm_kmemup() return value.

drivers/iio/multiplexer/iio-mux.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/iio/multiplexer/iio-mux.c b/drivers/iio/multiplexer/iio-mux.c
index 37ba007..74831fc 100644
--- a/drivers/iio/multiplexer/iio-mux.c
+++ b/drivers/iio/multiplexer/iio-mux.c
@@ -285,6 +285,9 @@ 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;

@@ -309,6 +312,9 @@ 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;
}
--
2.5.0