From: Amir Goldstein Date: Sun, 24 May 2020 07:24:41 +0000 (+0300) Subject: fanotify: fix ignore mask logic for events on child and on dir X-Git-Tag: v5.6.19~132 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c102db63155fa81652d898c972e471dd2e0c175c;p=thirdparty%2Fkernel%2Fstable.git fanotify: fix ignore mask logic for events on child and on dir [ Upstream commit 2f02fd3fa13e51713b630164f8a8e5b42de8283b ] 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@gmail.com Reported-by: Jan Kara Link: https://lore.kernel.org/linux-fsdevel/20200521162443.GA26052@quack2.suse.cz/ Fixes: 55bf882c7f13 "fanotify: fix merging marks masks with FAN_ONDIR" Fixes: b469e7e47c8a "fanotify: fix handling of events on child..." Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Signed-off-by: Sasha Levin --- diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index deb13f0a0f7d1..d24548ed31b98 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -171,6 +171,10 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, 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 on dir and this mark doesn't care about * events on dir, don't send it! @@ -188,7 +192,6 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, continue; marks_mask |= mark->mask; - marks_ignored_mask |= mark->ignored_mask; } test_mask = event_mask & marks_mask & ~marks_ignored_mask;