| From 55bf882c7f13dda8bbe624040c6d5b4fbb812d16 Mon Sep 17 00:00:00 2001 |
| From: Amir Goldstein <amir73il@gmail.com> |
| Date: Thu, 19 Mar 2020 17:10:17 +0200 |
| Subject: fanotify: fix merging marks masks with FAN_ONDIR |
| |
| From: Amir Goldstein <amir73il@gmail.com> |
| |
| commit 55bf882c7f13dda8bbe624040c6d5b4fbb812d16 upstream. |
| |
| Change the logic of FAN_ONDIR in two ways that are similar to the logic |
| of FAN_EVENT_ON_CHILD, that was fixed in commit 54a307ba8d3c ("fanotify: |
| fix logic of events on child"): |
| |
| 1. The flag is meaningless in ignore mask |
| 2. The flag refers only to events in the mask of the mark where it is set |
| |
| This is what the fanotify_mark.2 man page says about FAN_ONDIR: |
| "Without this flag, only events for files are created." It doesn't |
| say anything about setting this flag in ignore mask to stop getting |
| events on directories nor can I think of any setup where this capability |
| would be useful. |
| |
| Currently, when marks masks are merged, the FAN_ONDIR flag set in one |
| mark affects the events that are set in another mark's mask and this |
| behavior causes unexpected results. For example, a user adds a mark on a |
| directory with mask FAN_ATTRIB | FAN_ONDIR and a mount mark with mask |
| FAN_OPEN (without FAN_ONDIR). An opendir() of that directory (which is |
| inside that mount) generates a FAN_OPEN event even though neither of the |
| marks requested to get open events on directories. |
| |
| Link: https://lore.kernel.org/r/20200319151022.31456-10-amir73il@gmail.com |
| Signed-off-by: Amir Goldstein <amir73il@gmail.com> |
| Signed-off-by: Jan Kara <jack@suse.cz> |
| Cc: Rachel Sibley <rasibley@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/notify/fanotify/fanotify.c | 11 +++++++---- |
| 1 file changed, 7 insertions(+), 4 deletions(-) |
| |
| --- a/fs/notify/fanotify/fanotify.c |
| +++ b/fs/notify/fanotify/fanotify.c |
| @@ -172,6 +172,13 @@ static u32 fanotify_group_event_mask(str |
| continue; |
| mark = iter_info->marks[type]; |
| /* |
| + * If the event is on dir and this mark doesn't care about |
| + * events on dir, don't send it! |
| + */ |
| + if (event_mask & FS_ISDIR && !(mark->mask & FS_ISDIR)) |
| + continue; |
| + |
| + /* |
| * If the event is for a child and this mark doesn't care about |
| * events on a child, don't send it! |
| */ |
| @@ -203,10 +210,6 @@ static u32 fanotify_group_event_mask(str |
| user_mask &= ~FAN_ONDIR; |
| } |
| |
| - if (event_mask & FS_ISDIR && |
| - !(marks_mask & FS_ISDIR & ~marks_ignored_mask)) |
| - return 0; |
| - |
| return test_mask & user_mask; |
| } |
| |