The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 55bf882c7f13dda8bbe624040c6d5b4fbb812d16 Mon Sep 17 00:00:00 2001
From: Amir Goldstein <amir73il@xxxxxxxxx>
Date: Thu, 19 Mar 2020 17:10:17 +0200
Subject: [PATCH] fanotify: fix merging marks masks with FAN_ONDIR
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@xxxxxxxxx
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 97d34b958761..960f4f4d9e8f 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -171,6 +171,13 @@ 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];
+ /*
+ * 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(struct fsnotify_group *group,
user_mask &= ~FAN_ONDIR;
}
- if (event_mask & FS_ISDIR &&
- !(marks_mask & FS_ISDIR & ~marks_ignored_mask))
- return 0;
-
return test_mask & user_mask;
}
