On Mon, Jan 28, 2019 at 10:32:30PM +0100, Johannes Berg wrote: > At the same time, fixing all this _completely_ is not very realistic, it > would require passing the ifreq size through to lots of places and > making the user copy there take the size rather than sizeof(ifreq), > obviously the very least to the method decnet uses, i.e. sock->ioctl() I > think, but clearly that affects every other protocol too. > This was what my previous patch had done partially for the directly > handled ioctls (the revert of which is the first patch in this series). > > > From what I can see this looks like probably the simplest way to > > fix this in net and -stable currently. > > I tend to agree, at least to fix the regression. > > We can still deliberate separately if we want to fix decnet for compat > or if nobody cares now. But perhaps better decnet broken (quite > obviously and detectably) like it basically always was, than IP broken > (subtly, if your struct ends up landing at the end of a page). > > Al, care to speak up about this here?
Umm... Short-term I don't see anything better; long-term I would really like to see compat_alloc_user_space()/copy_in_user() crap gone and copyin-copyout for anything more or less generic lifted up as far as cleanly possible, but let's not mix it with regression fixing. So for the lack of better short-term solutions, Acked-by: Al Viro <v...@zeniv.linux.org.uk> on the series.
