From mboxrd@z Thu Jan 1 00:00:00 1970 From: hch@infradead.org (Christoph Hellwig) Date: Tue, 9 May 2017 23:54:48 -0700 Subject: [kernel-hardening] Re: [PATCH v9 1/4] syscalls: Verify address limit before returning to user-mode In-Reply-To: <20170510033911.GE390@ZenIV.linux.org.uk> References: <20170509064522.anusoikaalvlux3w@gmail.com> <20170509085659.GA32555@infradead.org> <20170509130250.GA11381@infradead.org> <20170509160322.GA15902@infradead.org> <20170510021118.GA390@ZenIV.linux.org.uk> <20170510024524.GB390@ZenIV.linux.org.uk> <20170510031254.GC390@ZenIV.linux.org.uk> <20170510032137.GD390@ZenIV.linux.org.uk> <20170510033911.GE390@ZenIV.linux.org.uk> Message-ID: <20170510065448.GD4115@infradead.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, May 10, 2017 at 04:39:12AM +0100, Al Viro wrote: > fcntl stuff: I've decided not to put something similar into work.compat > since I couldn't decide what to do with compat stuff - word-by-word copy > from userland converting to struct flock + conversion to posix_lock + > actual work + conversion to flock + word-by-word copy to userland... Smells > like we might be better off with compat_flock_to_posix_lock() et.al. > I'm still not sure; played a bit one way and another and dediced to drop > it for now. Hell knows... My version already is an improvement in lines of code alone. Between that and stopping to mess with the address limit I think it's a clear winner. But it's pretty independent of the rest, and I'll just run it through Jeff and Bruce and ask them what they think.