When compiling with GCC 9.0.0 I am seeing the following warning:
In function ‘fill_kobj_path’,
inlined from ‘kobject_get_path’ at lib/kobject.c:155:2:
lib/kobject.c:128:3: warning: ‘strncpy’ output truncated before terminating nul copying as many bytes from a string as its length [-Wstringop-truncation]
strncpy(path + length, kobject_name(parent), cur);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/kobject.c: In function ‘kobject_get_path’:
lib/kobject.c:125:13: note: length computed here
int cur = strlen(kobject_name(parent));
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
This is pointing out a bug that the strncpy limit is the source string not the
destination buffer remaining length. Fix it.
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Stafford Horne <shorne@xxxxxxxxx>
---
lib/kobject.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/kobject.c b/lib/kobject.c
index 18989b5b3b56..15338e5a96f2 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -125,7 +125,7 @@ static void fill_kobj_path(struct kobject *kobj, char *path, int length)
int cur = strlen(kobject_name(parent));
/* back up enough to print this name with '/' */
length -= cur;
- strncpy(path + length, kobject_name(parent), cur);
+ strncpy(path + length, kobject_name(parent), length);
*(path + --length) = '/';
}
--
2.17.0
