From: Azeem Shaikh <azeemshaikh38@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-hardening@vger.kernel.org,
Azeem Shaikh <azeemshaikh38@gmail.com>,
"Rafael J. Wysocki" <rafael@kernel.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH] kobject: Replace strlcpy with strscpy
Date: Mon, 3 Jul 2023 18:05:28 +0000 [thread overview]
Message-ID: <20230703180528.3709258-1-azeemshaikh38@gmail.com> (raw)
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
Direct replacement is safe here since return value of -errno
is used to check for truncation instead of sizeof(dest).
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
---
lib/kobject_uevent.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 7c44b7ae4c5c..e5497fa0a2d2 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -254,8 +254,8 @@ static int init_uevent_argv(struct kobj_uevent_env *env, const char *subsystem)
int buffer_size = sizeof(env->buf) - env->buflen;
int len;
- len = strlcpy(&env->buf[env->buflen], subsystem, buffer_size);
- if (len >= buffer_size) {
+ len = strscpy(&env->buf[env->buflen], subsystem, buffer_size);
+ if (len < 0) {
pr_warn("init_uevent_argv: buffer size of %d too small, needed %d\n",
buffer_size, len);
return -ENOMEM;
--
2.41.0.255.g8b1d071c50-goog
next reply other threads:[~2023-07-03 18:05 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-03 18:05 Azeem Shaikh [this message]
2023-07-10 13:13 ` [PATCH] kobject: Replace strlcpy with strscpy David Laight
2023-07-10 18:06 ` Azeem Shaikh
2023-07-11 8:14 ` David Laight
2023-07-12 23:52 ` Kees Cook
2023-07-13 8:18 ` David Laight
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