From: Stafford Horne <shorne@gmail.com>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Greg KH <gregkh@linuxfoundation.org>,
arnd@arndb.de, linux-crypto@vger.kernel.org,
Stafford Horne <shorne@gmail.com>
Subject: [RFC PATCH 2/2] kobject: Fix -Wstringop-truncation warning
Date: Sat, 23 Jun 2018 11:07:53 +0900 [thread overview]
Message-ID: <20180623020753.27266-3-shorne@gmail.com> (raw)
In-Reply-To: <20180623020753.27266-1-shorne@gmail.com>
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@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Stafford Horne <shorne@gmail.com>
---
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
next prev parent reply other threads:[~2018-06-23 2:07 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-23 2:07 [RFC PATCH 0/2] Fix GCC -Wstringop-truncation warnings Stafford Horne
2018-06-23 2:07 ` [RFC PATCH 1/2] crypto: Fix " Stafford Horne
2018-06-23 2:22 ` Max Filippov
2018-06-23 2:41 ` Eric Biggers
2018-06-23 2:52 ` Stafford Horne
2018-06-23 6:46 ` Stafford Horne
2018-06-23 2:07 ` Stafford Horne [this message]
2018-06-23 2:31 ` [RFC PATCH 2/2] kobject: Fix -Wstringop-truncation warning Eric Biggers
2018-06-23 2:50 ` Stafford Horne
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