From: Christoph Hellwig > Sent: 27 July 2020 17:24 > > On Mon, Jul 27, 2020 at 06:16:32PM +0200, Jason A. Donenfeld wrote: > > Maybe sockptr_advance should have some safety checks and sometimes > > return -EFAULT? Or you should always use the implementation where > > being a kernel address is an explicit bit of sockptr_t, rather than > > being implicit? > > I already have a patch to use access_ok to check the whole range in > init_user_sockptr. That doesn't make (much) difference to the code paths that ignore the user-supplied length. OTOH doing the user/kernel check on the base address (not an incremented one) means that the correct copy function is always selected. Perhaps the functions should all be passed a 'const sockptr_t'. The typedef could be made 'const' - requiring non-const items explicitly use the union/struct itself. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
