From dd0aa13fda824520da3fd980c3ed5f0628671aac Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 17 Jun 2024 18:23:00 +0200 Subject: [PATCH] fsnotify: Do not generate events for O_PATH file descriptors commit 702eb71fd6501b3566283f8c96d7ccc6ddd662e9 upstream. Currently we will not generate FS_OPEN events for O_PATH file descriptors but we will generate FS_CLOSE events for them. This is asymmetry is confusing. Arguably no fsnotify events should be generated for O_PATH file descriptors as they cannot be used to access or modify file content, they are just convenient handles to file objects like paths. So fix the asymmetry by stopping to generate FS_CLOSE for O_PATH file descriptors. Cc: Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20240617162303.1596-1-jack@suse.cz Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman --- include/linux/fsnotify.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index ed48e4f1e755..0dea8d0fdb0b 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -93,7 +93,13 @@ static inline int fsnotify_file(struct file *file, __u32 mask) { const struct path *path; - if (file->f_mode & FMODE_NONOTIFY) + /* + * FMODE_NONOTIFY are fds generated by fanotify itself which should not + * generate new events. We also don't want to generate events for + * FMODE_PATH fds (involves open & close events) as they are just + * handle creation / destruction events and not "real" file events. + */ + if (file->f_mode & (FMODE_NONOTIFY | FMODE_PATH)) return 0; /* Overlayfs internal files have fake f_path */