From: Amir Goldstein <amir73il@xxxxxxxxx> commit 2f02fd3fa13e51713b630164f8a8e5b42de8283b upstream. The comments in fanotify_group_event_mask() say: "If the event is on dir/child and this mark doesn't care about events on dir/child, don't send it!" Specifically, mount and filesystem marks do not care about events on child, but they can still specify an ignore mask for those events. For example, a group that has: - A mount mark with mask 0 and ignore_mask FAN_OPEN - An inode mark on a directory with mask FAN_OPEN | FAN_OPEN_EXEC with flag FAN_EVENT_ON_CHILD A child file open for exec would be reported to group with the FAN_OPEN event despite the fact that FAN_OPEN is in ignore mask of mount mark, because the mark iteration loop skips over non-inode marks for events on child when calculating the ignore mask. Move ignore mask calculation to the top of the iteration loop block before excluding marks for events on dir/child. Link: https://lore.kernel.org/r/20200524072441.18258-1-amir73il@xxxxxxxxx Reported-by: Jan Kara <jack@xxxxxxx> Link: https://lore.kernel.org/linux-fsdevel/20200521162443.GA26052@xxxxxxxxxxxxxx/ Fixes: 55bf882c7f13 "fanotify: fix merging marks masks with FAN_ONDIR" Fixes: b469e7e47c8a "fanotify: fix handling of events on child..." Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> Signed-off-by: Jan Kara <jack@xxxxxxx> Cc: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/notify/fanotify/fanotify.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index a18b8d7a30759..ca3405f732644 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -114,6 +114,10 @@ static bool fanotify_should_send_event(struct fsnotify_iter_info *iter_info, if (!fsnotify_iter_should_report_type(iter_info, type)) continue; mark = iter_info->marks[type]; + + /* Apply ignore mask regardless of ISDIR and ON_CHILD flags */ + marks_ignored_mask |= mark->ignored_mask; + /* * If the event is for a child and this mark doesn't care about * events on a child, don't send it! @@ -124,7 +128,6 @@ static bool fanotify_should_send_event(struct fsnotify_iter_info *iter_info, continue; marks_mask |= mark->mask; - marks_ignored_mask |= mark->ignored_mask; } if (d_is_dir(path->dentry) && -- 2.25.1
