mtd: check parts pointer before using it

The code has the check for parts but it called after kmemdup,
kmemdup(parts, sizeof(*parts) * nr_parts,...)
if (!parts)
	return -ENOMEM

In fact, we need check parts before safely using it.
and we also need check the real_parts to make sure kmemdup
allocation sucessfully.

Signed-off-by: Jason Liu <jason.hui@linaro.org>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 09bdbac51868..b01993ea260e 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -465,12 +465,13 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char **types,
         struct mtd_partition *real_parts;
 
         err = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
-        if (err <= 0 && nr_parts) {
+        if (err <= 0 && nr_parts && parts) {
                 real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
                                      GFP_KERNEL);
-                err = nr_parts;
-                if (!parts)
+                if (!real_parts)
                         err = -ENOMEM;
+                else
+                        err = nr_parts;
         }
 
         if (err > 0) {