From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Subject: [patches][RFC] situation with csum_and_copy_... API Date: Tue, 18 Nov 2014 19:40:53 +0000 Message-ID: <20141118194053.GA14641@ZenIV.linux.org.uk> References: <20141118084745.GT7996@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Linus Torvalds , David Miller , linux-kernel@vger.kernel.org To: netdev@vger.kernel.org Return-path: Content-Disposition: inline In-Reply-To: <20141118084745.GT7996@ZenIV.linux.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, Nov 18, 2014 at 08:47:45AM +0000, Al Viro wrote: > I do have a patch doing just that; the question is what to do with csum-and-copy > primitives. Originally I planned to simply strip those access_ok() from those > (both the explicit calls and use of copy_from_user() where we ought to use > __copy_from_user(), etc.), but that's not nice to potential out-of-tree callers > of those suckers. If any of those exist and manage to cope with the wonderful > calling conventions, that is. As it is, we have the total of 4 callers of > csum_and_copy_from_user() and 2 callers of csum_and_copy_to_user(), all in > networking code. Do we care about potential out-of-tree users existing and > getting screwed by such change? Davem, Linus? FWIW, the beginning of series in question follows; removal of those access_ok() is 3/5. The series is longer than that (see vfs.git#iov_iter-net for a bit more, and there's more stuff in local queue still too much in flux to push them out), but all the stuff relevant to validating iovecs on sendmsg/recvmsg and getting rid of excessive access_ok() is in the first 5 commits.