[PATCH v2 3/3] device property: avoid allocations of 0 length

From: Andy Shevchenko
Date: Wed Dec 23 2015 - 08:35:21 EST


Arrays can not have zero elements by definition of the unified device
properties. If such property comes from outside we should not allow it to pass.
Otherwise memory allocation on 0 length will return non-NULL value, which we
currently don't check.

Prevent memory allocations of 0 length.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/base/property.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 6c04d18..7e2061b 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -653,6 +653,9 @@ int fwnode_property_match_string(struct fwnode_handle *fwnode,
if (nval < 0)
return nval;

+ if (nval == 0)
+ return -ENODATA;
+
values = kcalloc(nval, sizeof(*values), GFP_KERNEL);
if (!values)
return -ENOMEM;
@@ -718,6 +721,9 @@ static int pset_copy_entry(struct property_entry *dst,
return -ENOMEM;

if (src->is_array) {
+ if (!src->length)
+ return -ENODATA;
+
if (src->is_string) {
nval = src->length / sizeof(const char *);
dst->pointer.str = kcalloc(nval, sizeof(const char *),
--
2.6.4

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