From: Johannes Berg > Sent: 09 October 2020 11:48 > > On Fri, 2020-10-09 at 12:41 +0200, Johannes Berg wrote: > > > If the fops doesn't have a release method, we don't even need > > to keep a reference to the real_fops, we can just fops_put() > > them already in debugfs remove, and a later full_proxy_release() > > won't call anything anyway - this just crashed/UAFed because it > > used real_fops, not because there was actually a (now invalid) > > release() method. > > I actually implemented something a bit better than what I described - we > never need a reference to the real_fops for the release method alone, > and that means if the release method is in the kernel image, rather than > a module, it can still be called. > > That together should reduce the ~117 places you changed in the large > patchset to around a handful. Is there an equivalent problem for normal cdev opens in any modules? David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
