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authorAmir Goldstein <amir73il@gmail.com>2021-03-04 13:29:21 +0200
committerJan Kara <jack@suse.cz>2021-03-16 16:55:05 +0100
commit7cea2a3c505e87a9d6afc78be4a7f7be636a73a7 (patch)
tree882cbff97b13a3f27259057d04be3bceff17e080 /fs/notify/fdinfo.c
parent5b8fea65d197f408bb00b251c70d842826d6b70b (diff)
fanotify: support limited functionality for unprivileged users
Add limited support for unprivileged fanotify groups. An unprivileged users is not allowed to get an open file descriptor in the event nor the process pid of another process. An unprivileged user cannot request permission events, cannot set mount/filesystem marks and cannot request unlimited queue/marks. This enables the limited functionality similar to inotify when watching a set of files and directories for OPEN/ACCESS/MODIFY/CLOSE events, without requiring SYS_CAP_ADMIN privileges. The FAN_REPORT_DFID_NAME init flag, provide a method for an unprivileged listener watching a set of directories (with FAN_EVENT_ON_CHILD) to monitor all changes inside those directories. This typically requires that the listener keeps a map of watched directory fid to dirfd (O_PATH), where fid is obtained with name_to_handle_at() before starting to watch for changes. When getting an event, the reported fid of the parent should be resolved to dirfd and fstatsat(2) with dirfd and name should be used to query the state of the filesystem entry. Link: https://lore.kernel.org/r/20210304112921.3996419-3-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/notify/fdinfo.c')
-rw-r--r--fs/notify/fdinfo.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/notify/fdinfo.c b/fs/notify/fdinfo.c
index f0d6b54be412..a712b2aaa9ac 100644
--- a/fs/notify/fdinfo.c
+++ b/fs/notify/fdinfo.c
@@ -144,7 +144,8 @@ void fanotify_show_fdinfo(struct seq_file *m, struct file *f)
struct fsnotify_group *group = f->private_data;
seq_printf(m, "fanotify flags:%x event-flags:%x\n",
- group->fanotify_data.flags, group->fanotify_data.f_flags);
+ group->fanotify_data.flags,
+ group->fanotify_data.f_flags);
show_fdinfo(m, f, fanotify_fdinfo);
}