From patchwork Mon Mar 31 20:10:52 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Stefan Metzmacher X-Patchwork-Id: 14033924 Received: from hr2.samba.org (hr2.samba.org [144.76.82.148]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0618121A440; Mon, 31 Mar 2025 20:11:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=144.76.82.148 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743451920; cv=none; b=m6Ejhv54mUWB2pg4Z0nn+meOZ5I2R2gn2NV1UbeiJWNm+vTzrLK/1cdfWp7BV6129LPWqF8gS5gmYfjsTAbOVvknEfnB8hmpGB8zLanTnDGAiT2FBT5d0qK84s5kQq+NJkC8HAhYXYWcDCjwqW07ZrhfsynCC+F3suMbuL66naI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743451920; c=relaxed/simple; bh=RNzXqslmQzT7+IeMpXEothGKbg0DnGRbDCZvHNoZApM=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version:Content-Type; b=OyZ4Nk6sEjgOLsIDAirxICpeduYwrcLQ9kKVO2dRGgT79zntqE17szRlkL8BfxoTBtRkMWYA5qJcqW5jcWm8KCViI5DtisoErlUWOAowmAHp656KyFHE8h+HhNYNvAJCoWJ8TjV8hd00G1qiWp+rLpMD59w8fj4z0YSVhN8rlEI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=samba.org; spf=pass smtp.mailfrom=samba.org; dkim=pass (3072-bit key) header.d=samba.org header.i=@samba.org header.b=VGP/0nn0; arc=none smtp.client-ip=144.76.82.148 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=samba.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=samba.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (3072-bit key) header.d=samba.org header.i=@samba.org header.b="VGP/0nn0" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=samba.org; s=42; h=Message-Id:Date:Cc:To:From; bh=ISfSMCAgKp8z55PiQhU0z6kwdG7zxeB+WY0nWqLYJPA=; b=VGP/0nn0y1hq6UZZ2Xgtb/aRCs b5dAxvYVE0vpLGixgXlJlDtn2SYHFl5m6kw6cdmrGgWYnVoxi+Q+6LQlvu7ezsvwdUqe7nCreq7Rb 65w9Ccui3mmYFh2hsx0NWTRw0bECxoj8ol1mr7dmQIe6lZfd2b9krDed7thG+VJl3/0QOj04fhid5 IulmHBJ24fLweRBGqNH1CkehpVbY61FQx0Xf2QNMa1gyo4f206+f+wHSPNrdnUljwqo4cuSzD7sGl vqgvLVJ72lG6qWQ4FP54CfAVHBYWjkbvKKycUYcvJ/C/N56w86Kri7QVQmJlokcodtPI51IOEe7/S n4yXvakpmRTnYwvgnXgXuznjLeG/teaA/Ici/DZJi2yYqTXruujvSSluQd0AaYTZ3aNtDWAa+x1iy n40hAdCLrl6bFwMBodJKjr5uFXD1AgYkGcPvxiFCuYFpaHJpRHj/lkwDPo6VL1Vzzih1pWdiVVNj/ yp6JlSH7/NlXybuT+tXxYkpk; Received: from [127.0.0.2] (localhost [127.0.0.1]) by hr2.samba.org with esmtpsa (TLS1.3:ECDHE_SECP256R1__ECDSA_SECP256R1_SHA256__CHACHA20_POLY1305:256) (Exim) id 1tzLTx-007Y5c-0g; Mon, 31 Mar 2025 20:11:41 +0000 From: Stefan Metzmacher To: Linus Torvalds , Jens Axboe Cc: Stefan Metzmacher , Pavel Begunkov , Breno Leitao , Jakub Kicinski , Christoph Hellwig , Karsten Keil , Ayush Sawal , Andrew Lunn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Kuniyuki Iwashima , Willem de Bruijn , David Ahern , Marcelo Ricardo Leitner , Xin Long , Neal Cardwell , Joerg Reuter , Marcel Holtmann , Johan Hedberg , Luiz Augusto von Dentz , Oliver Hartkopp , Marc Kleine-Budde , Robin van der Gracht , Oleksij Rempel , kernel@pengutronix.de, Alexander Aring , Stefan Schmidt , Miquel Raynal , Alexandra Winter , Thorsten Winkler , James Chapman , Jeremy Kerr , Matt Johnston , Matthieu Baerts , Mat Martineau , Geliang Tang , Krzysztof Kozlowski , Remi Denis-Courmont , Allison Henderson , David Howells , Marc Dionne , Wenjia Zhang , Jan Karcher , "D. Wythe" , Tony Lu , Wen Gu , Jon Maloy , Boris Pismenny , John Fastabend , Stefano Garzarella , Martin Schiller , =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , Magnus Karlsson , Maciej Fijalkowski , Jonathan Lemon , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sctp@vger.kernel.org, linux-hams@vger.kernel.org, linux-bluetooth@vger.kernel.org, linux-can@vger.kernel.org, dccp@vger.kernel.org, linux-wpan@vger.kernel.org, linux-s390@vger.kernel.org, mptcp@lists.linux.dev, linux-rdma@vger.kernel.org, rds-devel@oss.oracle.com, linux-afs@lists.infradead.org, tipc-discussion@lists.sourceforge.net, virtualization@lists.linux.dev, linux-x25@vger.kernel.org, bpf@vger.kernel.org, isdn4linux@listserv.isdn4linux.de, io-uring@vger.kernel.org Subject: [RFC PATCH 0/4] net/io_uring: pass a kernel pointer via optlen_t to proto[_ops].getsockopt() Date: Mon, 31 Mar 2025 22:10:52 +0200 Message-Id: X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-wpan@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The motivation for this is to remove the SOL_SOCKET limitation from io_uring_cmd_getsockopt(). The reason for this limitation is that io_uring_cmd_getsockopt() passes a kernel pointer as optlen to do_sock_getsockopt() and can't reach the ops->getsockopt() path. The first idea would be to change the optval and optlen arguments to the protocol specific hooks also to sockptr_t, as that is already used for setsockopt() and also by do_sock_getsockopt() sk_getsockopt() and BPF_CGROUP_RUN_PROG_GETSOCKOPT(). But as Linus don't like 'sockptr_t' I used a different approach. @Linus, would that optlen_t approach fit better for you? Instead of passing the optlen as user or kernel pointer, we only ever pass a kernel pointer and do the translation from/to userspace in do_sock_getsockopt(). The simple solution would be to just remove the '__user' from the int *optlen argument, but it seems the compiler doesn't complain about '__user' vs. without it, so instead I used a helper struct in order to make sure everything compiles with a typesafe change. The patchset does the transformation in 3 easy to review steps: 1/4: introduces get_optlen(len, optlen) and put_optlen(len, optlen) helpers on top of the existing get_user(len, optlen) and put_user(len, optlen) usages. 2/4: introduces a simple optlen_t that just contains 'int __user *up;' that makes sure get_optlen and put_optlen get a typesafe optlen argument and they are the only functions looking at optlen. (The existing sockptr_t optlen code gets OPTLEN_SOCKPTR(optlen) passed) 3/4: The changes do_sock_getsockopt() to pass a kernel pointer instead of a __user pointer via optlen_t. This is a bit tricky as directly failing the copy_from_sockptr(&koptlen, optlen, sizeof(koptlen) with -EFAULT might change the uapi, as some getsockopt() hooks doesn't even touch optlen at all. And userspace could do something like this: feature_x_supported = true; ret = getsockopt(fd, level, optname, NULL, NULL); if (ret == -1 && errno == ENOTSUPP) { feature_x_supported = false; } And this should not give -EFAULT after the changes, so optlen.kp is passed down as NULL, so that -EFAULT is deferred to get_optlen() and put_optlen(). 4/4: Removes the SOL_SOCKET restriction for io-uring. This patchset doesn't touch any existing getsockopt() that was already converted to sockptr_t optlen, that's something for a later cleanup. Link: https://lore.kernel.org/io-uring/86b1dce5-4bb4-4a0b-9cff-e72f488bf57d@samba.org/T/#t Cc: Jens Axboe Cc: Pavel Begunkov Cc: Breno Leitao Cc: Linus Torvalds Cc: Jakub Kicinski Cc: Christoph Hellwig Cc: Karsten Keil Cc: Ayush Sawal Cc: Andrew Lunn Cc: "David S. Miller" Cc: Eric Dumazet Cc: Paolo Abeni Cc: Simon Horman Cc: Kuniyuki Iwashima Cc: Willem de Bruijn Cc: David Ahern Cc: Marcelo Ricardo Leitner Cc: Xin Long Cc: Neal Cardwell Cc: Joerg Reuter Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Cc: Oliver Hartkopp Cc: Marc Kleine-Budde Cc: Robin van der Gracht Cc: Oleksij Rempel Cc: kernel@pengutronix.de Cc: Alexander Aring Cc: Stefan Schmidt Cc: Miquel Raynal Cc: Alexandra Winter Cc: Thorsten Winkler Cc: James Chapman Cc: Jeremy Kerr Cc: Matt Johnston Cc: Matthieu Baerts Cc: Mat Martineau Cc: Geliang Tang Cc: Krzysztof Kozlowski Cc: Remi Denis-Courmont Cc: Allison Henderson Cc: David Howells Cc: Marc Dionne Cc: Wenjia Zhang Cc: Jan Karcher Cc: "D. Wythe" Cc: Tony Lu Cc: Wen Gu Cc: Jon Maloy Cc: Boris Pismenny Cc: John Fastabend Cc: Stefano Garzarella Cc: Martin Schiller Cc: "Björn Töpel" Cc: Magnus Karlsson Cc: Maciej Fijalkowski Cc: Jonathan Lemon Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Jesper Dangaard Brouer CC: Stefan Metzmacher Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-sctp@vger.kernel.org Cc: linux-hams@vger.kernel.org Cc: linux-bluetooth@vger.kernel.org Cc: linux-can@vger.kernel.org Cc: dccp@vger.kernel.org Cc: linux-wpan@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: mptcp@lists.linux.dev Cc: linux-rdma@vger.kernel.org Cc: rds-devel@oss.oracle.com Cc: linux-afs@lists.infradead.org Cc: tipc-discussion@lists.sourceforge.net Cc: virtualization@lists.linux.dev Cc: linux-x25@vger.kernel.org Cc: bpf@vger.kernel.org Cc: isdn4linux@listserv.isdn4linux.de Cc: io-uring@vger.kernel.org Stefan Metzmacher (4): net: introduce get_optlen() and put_optlen() helpers net: pass 'optlen_t' to proto[ops].getsockopt() hooks net: pass a kernel pointer via 'optlen_t' to proto[ops].getsockopt() hooks io_uring: let io_uring_cmd_getsockopt() allow level other than SOL_SOCKET drivers/isdn/mISDN/socket.c | 4 +- .../chelsio/inline_crypto/chtls/chtls_main.c | 4 +- include/linux/net.h | 2 +- include/linux/sockptr.h | 41 ++++ include/net/inet_connection_sock.h | 2 +- include/net/ip.h | 2 +- include/net/ipv6.h | 2 +- include/net/sctp/structs.h | 2 +- include/net/sock.h | 4 +- include/net/tcp.h | 2 +- include/net/udp.h | 2 +- io_uring/uring_cmd.c | 3 - net/atm/common.c | 4 +- net/atm/common.h | 2 +- net/atm/pvc.c | 2 +- net/atm/svc.c | 4 +- net/ax25/af_ax25.c | 6 +- net/bluetooth/hci_sock.c | 6 +- net/bluetooth/iso.c | 6 +- net/bluetooth/l2cap_sock.c | 8 +- net/bluetooth/rfcomm/sock.c | 8 +- net/bluetooth/sco.c | 10 +- net/can/isotp.c | 6 +- net/can/j1939/socket.c | 6 +- net/can/raw.c | 14 +- net/core/sock.c | 2 +- net/dccp/ccid.c | 4 +- net/dccp/ccid.h | 10 +- net/dccp/ccids/ccid3.c | 8 +- net/dccp/dccp.h | 2 +- net/dccp/proto.c | 12 +- net/ieee802154/socket.c | 8 +- net/ipv4/ip_sockglue.c | 8 +- net/ipv4/raw.c | 10 +- net/ipv4/tcp.c | 4 +- net/ipv4/udp.c | 8 +- net/ipv4/udp_impl.h | 2 +- net/ipv6/ipv6_sockglue.c | 8 +- net/ipv6/raw.c | 14 +- net/ipv6/udp.c | 2 +- net/ipv6/udp_impl.h | 2 +- net/iucv/af_iucv.c | 6 +- net/kcm/kcmsock.c | 6 +- net/l2tp/l2tp_ppp.c | 6 +- net/llc/af_llc.c | 6 +- net/mctp/af_mctp.c | 4 +- net/mptcp/protocol.h | 2 +- net/mptcp/sockopt.c | 48 ++-- net/netlink/af_netlink.c | 8 +- net/netrom/af_netrom.c | 6 +- net/nfc/llcp_sock.c | 6 +- net/packet/af_packet.c | 6 +- net/phonet/pep.c | 6 +- net/rds/af_rds.c | 8 +- net/rds/info.c | 6 +- net/rds/info.h | 2 +- net/rose/af_rose.c | 6 +- net/rxrpc/af_rxrpc.c | 6 +- net/sctp/socket.c | 220 +++++++++--------- net/smc/af_smc.c | 8 +- net/smc/smc.h | 2 +- net/socket.c | 34 ++- net/tipc/socket.c | 8 +- net/tls/tls_main.c | 18 +- net/vmw_vsock/af_vsock.c | 6 +- net/x25/af_x25.c | 6 +- net/xdp/xsk.c | 10 +- 67 files changed, 387 insertions(+), 319 deletions(-)