[PATCH] inotify: Use strscpy() for event->name copies

Kees Cook
2024-12-16T22:45:20Z

Since we have already allocated "len + 1" space for event->name, make sure
that name->name cannot ever accidentally cause a copy overflow by calling
strscpy() instead of the unbounded strcpy() routine. This assists in
the ongoing efforts to remove the unsafe strcpy() API[1] from the kernel.

Link: https://github.com/KSPP/linux/issues/88 [1]
Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Jan Kara <jack@suse.cz>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: linux-fsdevel@vger.kernel.org
---
fs/notify/inotify/inotify_fsnotify.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c
index 993375f0db67..cd7d11b0eb08 100644
--- a/fs/notify/inotify/inotify_fsnotify.c
+++ b/fs/notify/inotify/inotify_fsnotify.c
@@ -121,7 +121,7 @@ int inotify_handle_inode_event(struct fsnotify_mark *inode_mark, u32 mask,
event->sync_cookie = cookie;
event->name_len = len;
if (len)
- strcpy(event->name, name->name);
+ strscpy(event->name, name->name, event->name_len + 1);

ret = fsnotify_add_event(group, fsn_event, inotify_merge);
if (ret) {
--
2.34.1