We do not want to report the dirfid+name of a directory whose
inode/sb are not watched, because watcher may not have permissions
to see the directory content.
The FAN_MOVED_FROM/TO flags are used internally to indicate to
fanotify_alloc_event() if we need to record only the old parent+name,
only the new parent+name or both.
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/notify/fanotify/fanotify.c | 57 ++++++++++++++++++++++++++++++-----
1 file changed, 50 insertions(+), 7 deletions(-)
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 018b32a57702..c0a3fb1dd066 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -290,6 +290,7 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group,
__u32 marks_mask = 0, marks_ignored_mask = 0;
__u32 test_mask, user_mask = FANOTIFY_OUTGOING_EVENTS |
FANOTIFY_EVENT_FLAGS;
+ __u32 moved_mask = 0;
const struct path *path = fsnotify_data_path(data, data_type);
unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
struct fsnotify_mark *mark;
@@ -327,17 +328,44 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group,
continue;
/*
- * If the event is on a child and this mark is on a parent not
- * watching children, don't send it!
+ * In the special case of FAN_RENAME event, inode mark is the
+ * mark on the old dir and parent mark is the mark on the new
+ * dir. We do not want to report the dirfid+name of a directory
+ * whose inode/sb are not watched. The FAN_MOVE flags
+ * are used internally to indicate if we need to report only
+ * the old parent+name, only the new parent+name or both.
*/
- if (type == FSNOTIFY_OBJ_TYPE_PARENT &&
- !(mark->mask & FS_EVENT_ON_CHILD))
+ if (event_mask & FAN_RENAME) {
+ /* Old dir sb are watched - report old info */
+ if (type != FSNOTIFY_OBJ_TYPE_PARENT &&
+ (mark->mask & FAN_RENAME))
+ moved_mask |= FAN_MOVED_FROM;
+ /* New dir sb are watched - report new info */
+ if (type != FSNOTIFY_OBJ_TYPE_INODE &&
+ (mark->mask & FAN_RENAME))
+ moved_mask |= FAN_MOVED_TO;
+ } else if (type == FSNOTIFY_OBJ_TYPE_PARENT &&
+ !(mark->mask & FS_EVENT_ON_CHILD)) {
+ /*
+ * If the event is on a child and this mark is on
+ * a parent not watching children, don't send it!
+ */
continue;
+ }
marks_mask |= mark->mask;
}
test_mask = event_mask & marks_mask & ~marks_ignored_mask;
+ /*
+ * Add the internal FAN_MOVE flags to FAN_RENAME event.
+ * They will not be reported to user along with FAN_RENAME.
+ */
+ if (test_mask & FAN_RENAME) {
+ if (WARN_ON_ONCE(test_mask & FAN_MOVE))
+ return 0;
+ test_mask |= moved_mask;
+ }
/*
* For dirent modification events (create/delete/move) that do not carry
@@ -753,13 +781,28 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
}
/*
- * In the special case of FAN_RENAME event, we record both
- * old and new parent+name.
+ * In the special case of FAN_RENAME event, the FAN_MOVE flags
+ * are only used internally to indicate if we need to report
+ * only the old parent+name, only the new parent+name or both.
* 'dirid' and 'file_name' are the old parent+name and
* 'moved' has the new parent+name.
*/
if (mask & FAN_RENAME) {
- moved = fsnotify_data_dentry(data, data_type);
+ /* Either old and/or new info must be reported */
+ if (WARN_ON_ONCE(!(mask & FAN_MOVE)))
+ return NULL;
+
+ if (!(mask & FAN_MOVED_FROM)) {
+ /* Do not report old parent+name */
+ dirid = NULL;
+ file_name = NULL;
+ }
+ if (mask & FAN_MOVED_TO) {
+ /* Report new parent+name */
+ moved = fsnotify_data_dentry(data, data_type);
+ }
+ /* Clear internal flags */
+ mask &= ~FAN_MOVE;
name_event = true;
}
}
--
2.33.1
