From 711f9b8fbe4f4936302804e246e206f0829f628f Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Mon, 3 Feb 2025 23:32:05 +0100 Subject: [PATCH] fsnotify: disable pre-content and permission events by default After introducing pre-content events, we had a regression related to disabling huge faults on files that should never have pre-content events enabled. This happened because the default f_mode of allocated files (0) does not disable pre-content events. Pre-content events are disabled in file_set_fsnotify_mode_by_watchers() but internal files may not get to call this helper. Initialize f_mode to disable permission and pre-content events for all files and if needed they will be enabled for the callers of file_set_fsnotify_mode_by_watchers(). Fixes: 20bf82a898b6 ("mm: don't allow huge faults for files with pre content watches") Reported-by: Alex Williamson Closes: https://lore.kernel.org/linux-fsdevel/20250131121703.1e4d00a7.alex.williamson@redhat.com/ Tested-by: Alex Williamson Signed-off-by: Amir Goldstein Link: https://lore.kernel.org/r/20250203223205.861346-4-amir73il@gmail.com Signed-off-by: Christian Brauner --- fs/file_table.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/file_table.c b/fs/file_table.c index 35b93da6c5cb1..5c00dc38558da 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -194,6 +194,11 @@ static int init_file(struct file *f, int flags, const struct cred *cred) * refcount bumps we should reinitialize the reused file first. */ file_ref_init(&f->f_ref, 1); + /* + * Disable permission and pre-content events for all files by default. + * They may be enabled later by file_set_fsnotify_mode_from_watchers(). + */ + file_set_fsnotify_mode(f, FMODE_NONOTIFY_PERM); return 0; } -- 2.49.0