Messages in this thread | | | Date | Fri, 25 Feb 2011 12:57:09 -0800 | From | Greg KH <> | Subject | Re: [PATCH 2/2] debugfs: only allow root access to debugging interfaces |
| |
On Fri, Feb 25, 2011 at 12:40:43PM -0800, Hugh Dickins wrote: > On Fri, 25 Feb 2011, Greg KH wrote: > > On Tue, Feb 22, 2011 at 11:29:15PM +0300, Dan Carpenter wrote: > > > On Tue, Feb 22, 2011 at 11:33:14AM -0800, Greg KH wrote: > > > > Again, let's fix the real problems here, world-writable debugfs files. > > > > > > We could just ban them? > > > > > > diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c > > > index e7a7a2f..03ae095 100644 > > > --- a/fs/debugfs/inode.c > > > +++ b/fs/debugfs/inode.c > > > @@ -223,6 +223,9 @@ struct dentry *debugfs_create_file(const char *name, mode_t mode, > > > > > > pr_debug("debugfs: creating file '%s'\n",name); > > > > > > + /* don't allow world writable files */ > > > + mode &= ~S_IWOTH; > > > + > > > error = simple_pin_fs(&debug_fs_type, &debugfs_mount, > > > &debugfs_mount_count); > > > if (error) > > > > > > > I have no objection to this patch, care to resend it with a > > signed-off-by: so that I can apply it? > > That's funny, I wrote something in debugfs a few months ago which was > very deliberately rw--w--w-: a kind of circular trace buffer into which > any userspace could easily echo its progress for debugging. > > Probably won't be upstreamed in that form, nor use debugfs if it is. > But I mention it as an example of why any such limitation on debugfs > seems inappropriate to me.
Ok, fair enough, then I'll not add this patch, as you just proved it is a valuable thing to have world writable debugfs files.
thanks,
greg k-h
| |