clocksource: Replace all non-returning 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().
No return values were used, so direct replacement is safe.

[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>
Acked-by: John Stultz <jstultz@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230530163546.986188-1-azeemshaikh38@gmail.com

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 91836b7..88cbc11 100644 (file)
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -1480,7 +1480,7 @@ static int __init boot_override_clocksource(char* str)
 {
        mutex_lock(&clocksource_mutex);
        if (str)
-               strlcpy(override_name, str, sizeof(override_name));
+               strscpy(override_name, str, sizeof(override_name));
        mutex_unlock(&clocksource_mutex);
        return 1;
 }