From 6cd59324c69a8d30956c70a870dcd0cb14977914 Mon Sep 17 00:00:00 2001 From: Azeem Shaikh Date: Thu, 31 Aug 2023 14:01:04 +0000 Subject: kobject: Replace strlcpy with strscpy 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 Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20230831140104.207019-1-azeemshaikh38@gmail.com Signed-off-by: Kees Cook --- lib/kobject_uevent.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'lib') diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 7c44b7ae4c5c..fb9a2f06dd1e 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -254,10 +254,10 @@ 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) { - pr_warn("init_uevent_argv: buffer size of %d too small, needed %d\n", - buffer_size, len); + len = strscpy(&env->buf[env->buflen], subsystem, buffer_size); + if (len < 0) { + pr_warn("%s: insufficient buffer space (%u left) for %s\n", + __func__, buffer_size, subsystem); return -ENOMEM; } -- cgit v1.2.3