From 07f8230b4b39b8b7fb401a67f308c61a43542402 Mon Sep 17 00:00:00 2001 From: Justin Stitt Date: Tue, 2 Apr 2024 20:39:49 +0000 Subject: [PATCH] init: replace deprecated strncpy with strscpy_pad strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. data_page wants to be NUL-terminated and NUL-padded, use strscpy_pad to provide both of these. data_page no longer awkwardly relies on init_mount to perform its NUL-termination, although that sanity check is left unchanged. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: Signed-off-by: Justin Stitt Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20240402-strncpy-init-do_mounts-c-v1-1-e16d7bc20974@google.com Signed-off-by: Kees Cook --- init/do_mounts.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/init/do_mounts.c b/init/do_mounts.c index 3c5fd993bc7e..6af29da8889e 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -159,8 +159,7 @@ static int __init do_mount_root(const char *name, const char *fs, if (!p) return -ENOMEM; data_page = page_address(p); - /* zero-pad. init_mount() will make sure it's terminated */ - strncpy(data_page, data, PAGE_SIZE); + strscpy_pad(data_page, data, PAGE_SIZE); } ret = init_mount(name, "/root", fs, flags, data_page);