From 7cfcb65054ae050d488a5ea1edcfbe9cccc7a42b 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 e9d2024473b0..e266cac311c3 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -62,7 +62,13 @@ static inline int fsnotify_perm(struct file *file, int mask) struct inode *inode = file_inode(file); __u32 fsnotify_mask = 0; - 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; if (!(mask & (MAY_READ | MAY_OPEN))) return 0;