[PATCH] thunderbolt: property: fix a buffer overflow and a missing check

From: Kangjie Lu
Date: Sun Mar 24 2019 - 19:01:16 EST


First, no memory is allocated for "property->value.text"; the
following strcpy will lead to a buffer overflow.

Second, no check is enforced for the return value of kzalloc,
which may lead to NULL-pointer dereference.

The patch fixes the two issues.

Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
---
drivers/thunderbolt/property.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/thunderbolt/property.c b/drivers/thunderbolt/property.c
index 841314deb446..d5b0cdb8f0b1 100644
--- a/drivers/thunderbolt/property.c
+++ b/drivers/thunderbolt/property.c
@@ -587,7 +587,12 @@ int tb_property_add_text(struct tb_property_dir *parent, const char *key,
return -ENOMEM;

property->length = size / 4;
- property->value.data = kzalloc(size, GFP_KERNEL);
+ property->value.text = kzalloc(size, GFP_KERNEL);
+ if (!property->value.text) {
+ kfree(property);
+ return -ENOMEM;
+ }
+
strcpy(property->value.text, text);

list_add_tail(&property->list, &parent->properties);
--
2.17.1