From 75041ebed0aaa9ab31bdd8ccc806933decb18a7a 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 BugLink: https://bugs.launchpad.net/bugs/2077600 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 Signed-off-by: Portia Stephens Signed-off-by: Roxana Nicolescu --- 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 8300a5286988..418c83f26565 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; path = &file->f_path;