From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52121C77B61 for ; Thu, 13 Apr 2023 20:49:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B38156B0072; Thu, 13 Apr 2023 16:49:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AE9196B0074; Thu, 13 Apr 2023 16:49:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9D6DD6B0075; Thu, 13 Apr 2023 16:49:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 8F8676B0072 for ; Thu, 13 Apr 2023 16:49:41 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 5DC151203FE for ; Thu, 13 Apr 2023 20:49:41 +0000 (UTC) X-FDA: 80677558962.12.0D28E1F Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) by imf21.hostedemail.com (Postfix) with ESMTP id A75121C0008 for ; Thu, 13 Apr 2023 20:49:38 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=linux.org.uk header.s=zeniv-20220401 header.b=TXn26RqZ; spf=none (imf21.hostedemail.com: domain of viro@ftp.linux.org.uk has no SPF policy when checking 62.89.141.173) smtp.mailfrom=viro@ftp.linux.org.uk; dmarc=pass (policy=none) header.from=zeniv.linux.org.uk ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1681418978; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=AKRqjOKvWTh8AITsGTpW2W5M1sf4F1a2mFDS4K7IwUQ=; b=ZbZ838fNuD0kkdUOpWSZ+NAGPbHcZOcmk8rqrxG5q4IDPtwQ+73MI5i0nePUyIn45NR/Uv s5yeOnEHlJbFg6p3y9k9zqYFBZyzlnHPBTx0olAEAx5IilBuiN97uL84aBG4qbyrTAG/DL 6IAPMgbmEjKaq5AKpS+dG51i9y6K2EE= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=linux.org.uk header.s=zeniv-20220401 header.b=TXn26RqZ; spf=none (imf21.hostedemail.com: domain of viro@ftp.linux.org.uk has no SPF policy when checking 62.89.141.173) smtp.mailfrom=viro@ftp.linux.org.uk; dmarc=pass (policy=none) header.from=zeniv.linux.org.uk ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1681418978; a=rsa-sha256; cv=none; b=5urEZRGP69gw5a5a62GF6b4A1iniQejiH4s95kAdijW3mgGeOn546BzRuEhgAhIwrdMpRg BW0+ndZ1VS83IuAZ3P6WrPjwP/EvPR4UfiNFOPxaC8ZbGRywXa5QUs1TyO+iBACD48dFzu 62zutuB9DhAAU/7B84uKHQ0ue0I4T4c= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=AKRqjOKvWTh8AITsGTpW2W5M1sf4F1a2mFDS4K7IwUQ=; b=TXn26RqZfT59uUv6txfliptdy0 uljFWZK01bsVf+kp7pZsRM+hew3avu6LrziesUVT8qcKJolEv+3vkQN3aXIvVqQZ26i82PRybKaBG yxEybz4Xy3M26l2wmjouqiL/7XqyvNn1hiyD4IEHuckYM2ywqD6V8kmsUbB5Qjw6fxpDgtGvvI5f2 pWAZf/uNesA+LjMXh6xADfBb1WYmz8wSq95v4JFKDK2cFM+mrjzAvL8j5Saqh+pQSRYTtjuIptZed ED2/+oqFIyhIIjRHzyePENhxrRvRx2ngir/yD3rHKVvIqMz6IYudp5gcHww08AWexJ55jzn1tXQ+F 3mMDm+7A==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.96 #2 (Red Hat Linux)) id 1pn3sc-008jyb-36; Thu, 13 Apr 2023 20:49:19 +0000 Date: Thu, 13 Apr 2023 21:49:18 +0100 From: Al Viro To: David Howells Cc: netdev@vger.kernel.org, "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Willem de Bruijn , David Ahern , Matthew Wilcox , Christoph Hellwig , Jens Axboe , Jeff Layton , Christian Brauner , Chuck Lever III , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Willem de Bruijn Subject: Re: [PATCH net-next v6 01/18] net: Declare MSG_SPLICE_PAGES internal sendmsg() flag Message-ID: <20230413204918.GC3390869@ZenIV> References: <20230413042917.GA3390869@ZenIV> <20230411160902.4134381-1-dhowells@redhat.com> <20230411160902.4134381-2-dhowells@redhat.com> <20230413005129.GZ3390869@ZenIV> <1147766.1681418362@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1147766.1681418362@warthog.procyon.org.uk> X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: A75121C0008 X-Stat-Signature: txp9mu8qyddeux4natew83shkikt9g64 X-HE-Tag: 1681418978-762149 X-HE-Meta: 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 /t8lfGw/ 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Apr 13, 2023 at 09:39:22PM +0100, David Howells wrote: > Al Viro wrote: > > > Note that io_sendmsg_prep() handles both IORING_OP_SENDMSG and IORING_OP_SEND, > > so this pair of functions can hit the same request. And sqe->msg_flags is > > not sanitized at all - it comes straight from user buffer. > > Assuming ____sys_sendmsg() is fixed, I think it should be sufficient to make > io_send() and io_send_zc(). io_sendmsg() and io_sendmsg_zc() will go through > ____sys_sendmsg(). Sure; what I wanted to point out was that despite the name, io_sendmsg_prep() gets used not only with io_sendmsg(). io_sendmsg() does go through ____sys_sendmsg(), but io_send() goes straight to sock_sendmsg() and evades all your checks...