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2024-10-15mptcp: prevent MPC handshake on port-based signal endpointsPaolo Abeni1-0/+11
Syzkaller reported a lockdep splat: ============================================ WARNING: possible recursive locking detected 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Not tainted -------------------------------------------- syz-executor364/5113 is trying to acquire lock: ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 but task is already holding lock: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(k-slock-AF_INET); lock(k-slock-AF_INET); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by syz-executor364/5113: #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x153/0x1b10 net/mptcp/protocol.c:1806 #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg_fastopen+0x11f/0x530 net/mptcp/protocol.c:1727 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x5f/0x1b80 net/ipv4/ip_output.c:470 #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1390 net/ipv4/ip_output.c:228 #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104 #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x230/0x5f0 net/ipv4/ip_input.c:232 #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 stack backtrace: CPU: 0 UID: 0 PID: 5113 Comm: syz-executor364 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_deadlock kernel/locking/lockdep.c:3061 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 mptcp_sk_clone_init+0x32/0x13c0 net/mptcp/protocol.c:3279 subflow_syn_recv_sock+0x931/0x1920 net/mptcp/subflow.c:874 tcp_check_req+0xfe4/0x1a20 net/ipv4/tcp_minisocks.c:853 tcp_v4_rcv+0x1c3e/0x37f0 net/ipv4/tcp_ipv4.c:2267 ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5661 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6108 __napi_poll+0xcb/0x490 net/core/dev.c:6772 napi_poll net/core/dev.c:6841 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6963 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 </IRQ> <TASK> __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline] __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450 dev_queue_xmit include/linux/netdevice.h:3105 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235 ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6542 [inline] tcp_rcv_state_process+0x2c32/0x4570 net/ipv4/tcp_input.c:6729 tcp_v4_do_rcv+0x77d/0xc70 net/ipv4/tcp_ipv4.c:1934 sk_backlog_rcv include/net/sock.h:1111 [inline] __release_sock+0x214/0x350 net/core/sock.c:3004 release_sock+0x61/0x1f0 net/core/sock.c:3558 mptcp_sendmsg_fastopen+0x1ad/0x530 net/mptcp/protocol.c:1733 mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1812 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f04fb13a6b9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd651f42d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04fb13a6b9 RDX: 0000000000000001 RSI: 0000000020000d00 RDI: 0000000000000004 RBP: 00007ffd651f4310 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000020000080 R11: 0000000000000246 R12: 00000000000f4240 R13: 00007f04fb187449 R14: 00007ffd651f42f4 R15: 00007ffd651f4300 </TASK> As noted by Cong Wang, the splat is false positive, but the code path leading to the report is an unexpected one: a client is attempting an MPC handshake towards the in-kernel listener created by the in-kernel PM for a port based signal endpoint. Such connection will be never accepted; many of them can make the listener queue full and preventing the creation of MPJ subflow via such listener - its intended role. Explicitly detect this scenario at initial-syn time and drop the incoming MPC request. Fixes: 1729cf186d8a ("mptcp: create the listening socket for new port") Cc: stable@vger.kernel.org Reported-by: syzbot+f4aacdfef2c6a6529c3e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f4aacdfef2c6a6529c3e Cc: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20241014-net-mptcp-mpc-port-endp-v2-1-7faea8e6b6ae@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-09mptcp: fallback when MPTCP opts are dropped after 1st dataMatthieu Baerts (NGI0)1-1/+1
As reported by Christoph [1], before this patch, an MPTCP connection was wrongly reset when a host received a first data packet with MPTCP options after the 3wHS, but got the next ones without. According to the MPTCP v1 specs [2], a fallback should happen in this case, because the host didn't receive a DATA_ACK from the other peer, nor receive data for more than the initial window which implies a DATA_ACK being received by the other peer. The patch here re-uses the same logic as the one used in other places: by looking at allow_infinite_fallback, which is disabled at the creation of an additional subflow. It's not looking at the first DATA_ACK (or implying one received from the other side) as suggested by the RFC, but it is in continuation with what was already done, which is safer, and it fixes the reported issue. The next step, looking at this first DATA_ACK, is tracked in [4]. This patch has been validated using the following Packetdrill script: 0 socket(..., SOCK_STREAM, IPPROTO_MPTCP) = 3 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 +0 bind(3, ..., ...) = 0 +0 listen(3, 1) = 0 // 3WHS is OK +0.0 < S 0:0(0) win 65535 <mss 1460, sackOK, nop, nop, nop, wscale 6, mpcapable v1 flags[flag_h] nokey> +0.0 > S. 0:0(0) ack 1 <mss 1460, nop, nop, sackOK, nop, wscale 8, mpcapable v1 flags[flag_h] key[skey]> +0.1 < . 1:1(0) ack 1 win 2048 <mpcapable v1 flags[flag_h] key[ckey=2, skey]> +0 accept(3, ..., ...) = 4 // Data from the client with valid MPTCP options (no DATA_ACK: normal) +0.1 < P. 1:501(500) ack 1 win 2048 <mpcapable v1 flags[flag_h] key[skey, ckey] mpcdatalen 500, nop, nop> // From here, the MPTCP options will be dropped by a middlebox +0.0 > . 1:1(0) ack 501 <dss dack8=501 dll=0 nocs> +0.1 read(4, ..., 500) = 500 +0 write(4, ..., 100) = 100 // The server replies with data, still thinking MPTCP is being used +0.0 > P. 1:101(100) ack 501 <dss dack8=501 dsn8=1 ssn=1 dll=100 nocs, nop, nop> // But the client already did a fallback to TCP, because the two previous packets have been received without MPTCP options +0.1 < . 501:501(0) ack 101 win 2048 +0.0 < P. 501:601(100) ack 101 win 2048 // The server should fallback to TCP, not reset: it didn't get a DATA_ACK, nor data for more than the initial window +0.0 > . 101:101(0) ack 601 Note that this script requires Packetdrill with MPTCP support, see [3]. Fixes: dea2b1ea9c70 ("mptcp: do not reset MP_CAPABLE subflow on mapping errors") Cc: stable@vger.kernel.org Reported-by: Christoph Paasch <cpaasch@apple.com> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/518 [1] Link: https://datatracker.ietf.org/doc/html/rfc8684#name-fallback [2] Link: https://github.com/multipath-tcp/packetdrill [3] Link: https://github.com/multipath-tcp/mptcp_net-next/issues/519 [4] Reviewed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20241008-net-mptcp-fallback-fixes-v1-3-c6fb8e93e551@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-09mptcp: handle consistently DSS corruptionPaolo Abeni1-1/+3
Bugged peer implementation can send corrupted DSS options, consistently hitting a few warning in the data path. Use DEBUG_NET assertions, to avoid the splat on some builds and handle consistently the error, dumping related MIBs and performing fallback and/or reset according to the subflow type. Fixes: 6771bfd9ee24 ("mptcp: update mptcp ack sequence from work queue") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20241008-net-mptcp-fallback-fixes-v1-1-c6fb8e93e551@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-11mptcp: disable active MPTCP in case of blackholeMatthieu Baerts (NGI0)1-0/+4
An MPTCP firewall blackhole can be detected if the following SYN retransmission after a fallback to "plain" TCP is accepted. In case of blackhole, a similar technique to the one in place with TFO is now used: MPTCP can be disabled for a certain period of time, 1h by default. This time period will grow exponentially when more blackhole issues get detected right after MPTCP is re-enabled and will reset to the initial value when the blackhole issue goes away. The blackhole period can be modified thanks to a new sysctl knob: blackhole_timeout. Two new MIB counters help understanding what's happening: - 'Blackhole', incremented when a blackhole is detected. - 'MPCapableSYNTXDisabled', incremented when an MPTCP connection directly falls back to TCP during the blackhole period. Because the technique is inspired by the one used by TFO, an important part of the new code is similar to what can find in tcp_fastopen.c, with some adaptations to the MPTCP case. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/57 Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20240909-net-next-mptcp-fallback-x-mpc-v1-3-da7ebb4cd2a3@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-03mptcp: MIB counters for sent MP_JOINMatthieu Baerts (NGI0)1-3/+18
Recently, a few issues have been discovered around the creation of additional subflows. Without these counters, it was difficult to point out the reason why some subflows were not created as expected. These counters should have been added earlier, because there is no other simple ways to extract such information from the kernel, and understand why subflows have not been created. While at it, some pr_debug() have been added, just in case the errno needs to be printed. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/509 Reviewed-by: Geliang Tang <geliang@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20240902-net-next-mptcp-mib-mpjtx-misc-v1-3-d3e0f3773b90@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-03mptcp: pm: reduce entries iterations on connectMatthieu Baerts (NGI0)1-11/+18
__mptcp_subflow_connect() is currently called from the path-managers, which have all the required information to create subflows. No need to call the PM again to re-iterate over the list of entries with RCU lock to get more info. Instead, it is possible to pass a mptcp_pm_addr_entry structure, instead of a mptcp_addr_info one. The former contains the ifindex and the flags that are required when creating the new subflow. This is a partial revert of commit ee285257a9c1 ("mptcp: drop flags and ifindex arguments"). While at it, the local ID can also be set if it is known and 0, to avoid having to set it in the 'rebuild_header' hook, which will cause a new iteration of the endpoint entries. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20240902-net-next-mptcp-mib-mpjtx-misc-v1-2-d3e0f3773b90@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-27mptcp: pr_debug: add missing \n at the endMatthieu Baerts (NGI0)1-24/+24
pr_debug() have been added in various places in MPTCP code to help developers to debug some situations. With the dynamic debug feature, it is easy to enable all or some of them, and asks users to reproduce issues with extra debug. Many of these pr_debug() don't end with a new line, while no 'pr_cont()' are used in MPTCP code. So the goal was not to display multiple debug messages on one line: they were then not missing the '\n' on purpose. Not having the new line at the end causes these messages to be printed with a delay, when something else needs to be printed. This issue is not visible when many messages need to be printed, but it is annoying and confusing when only specific messages are expected, e.g. # echo "func mptcp_pm_add_addr_echoed +fmp" \ > /sys/kernel/debug/dynamic_debug/control # ./mptcp_join.sh "signal address"; \ echo "$(awk '{print $1}' /proc/uptime) - end"; \ sleep 5s; \ echo "$(awk '{print $1}' /proc/uptime) - restart"; \ ./mptcp_join.sh "signal address" 013 signal address (...) 10.75 - end 15.76 - restart 013 signal address [ 10.367935] mptcp:mptcp_pm_add_addr_echoed: MPTCP: msk=(...) (...) => a delay of 5 seconds: printed with a 10.36 ts, but after 'restart' which was printed at the 15.76 ts. The 'Fixes' tag here below points to the first pr_debug() used without '\n' in net/mptcp. This patch could be split in many small ones, with different Fixes tag, but it doesn't seem worth it, because it is easy to re-generate this patch with this simple 'sed' command: git grep -l pr_debug -- net/mptcp | xargs sed -i "s/\(pr_debug(\".*[^n]\)\(\"[,)]\)/\1\\\n\2/g" So in case of conflicts, simply drop the modifications, and launch this command. Fixes: f870fa0b5768 ("mptcp: Add MPTCP socket stubs") Cc: stable@vger.kernel.org Reviewed-by: Geliang Tang <geliang@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20240826-net-mptcp-close-extra-sf-fin-v1-4-905199fe1172@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-27mptcp: close subflow when receiving TCP+FINMatthieu Baerts (NGI0)1-2/+6
When a peer decides to close one subflow in the middle of a connection having multiple subflows, the receiver of the first FIN should accept that, and close the subflow on its side as well. If not, the subflow will stay half closed, and would even continue to be used until the end of the MPTCP connection or a reset from the network. The issue has not been seen before, probably because the in-kernel path-manager always sends a RM_ADDR before closing the subflow. Upon the reception of this RM_ADDR, the other peer will initiate the closure on its side as well. On the other hand, if the RM_ADDR is lost, or if the path-manager of the other peer only closes the subflow without sending a RM_ADDR, the subflow would switch to TCP_CLOSE_WAIT, but that's it, leaving the subflow half-closed. So now, when the subflow switches to the TCP_CLOSE_WAIT state, and if the MPTCP connection has not been closed before with a DATA_FIN, the kernel owning the subflow schedules its worker to initiate the closure on its side as well. This issue can be easily reproduced with packetdrill, as visible in [1], by creating an additional subflow, injecting a FIN+ACK before sending the DATA_FIN, and expecting a FIN+ACK in return. Fixes: 40947e13997a ("mptcp: schedule worker when subflow is closed") Cc: stable@vger.kernel.org Link: https://github.com/multipath-tcp/packetdrill/pull/154 [1] Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20240826-net-mptcp-close-extra-sf-fin-v1-1-905199fe1172@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-01mptcp: fix duplicate data handlingPaolo Abeni1-4/+12
When a subflow receives and discards duplicate data, the mptcp stack assumes that the consumed offset inside the current skb is zero. With multiple subflows receiving data simultaneously such assertion does not held true. As a result the subflow-level copied_seq will be incorrectly increased and later on the same subflow will observe a bad mapping, leading to subflow reset. Address the issue taking into account the skb consumed offset in mptcp_subflow_discard_data(). Fixes: 04e4cd4f7ca4 ("mptcp: cleanup mptcp_subflow_discard_data()") Cc: stable@vger.kernel.org Link: https://github.com/multipath-tcp/mptcp_net-next/issues/501 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-07-30mptcp: pm: fix backup support in signal endpointsMatthieu Baerts (NGI0)1-0/+3
There was a support for signal endpoints, but only when the endpoint's flag was changed during a connection. If an endpoint with the signal and backup was already present, the MP_JOIN reply was not containing the backup flag as expected. That's confusing to have this inconsistent behaviour. On the other hand, the infrastructure to set the backup flag in the SYN + ACK + MP_JOIN was already there, it was just never set before. Now when requesting the local ID from the path-manager, the backup status is also requested. Note that when the userspace PM is used, the backup flag can be set if the local address was already used before with a backup flag, e.g. if the address was announced with the 'backup' flag, or a subflow was created with the 'backup' flag. Fixes: 4596a2c1b7f5 ("mptcp: allow creating non-backup subflows") Cc: stable@vger.kernel.org Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/507 Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-07-30mptcp: mib: count MPJ with backup flagMatthieu Baerts (NGI0)1-0/+6
Without such counters, it is difficult to easily debug issues with MPJ not having the backup flags on production servers. This is not strictly a fix, but it eases to validate the following patches without requiring to take packet traces, to query ongoing connections with Netlink with admin permissions, or to guess by looking at the behaviour of the packet scheduler. Also, the modification is self contained, isolated, well controlled, and the increments are done just after others, there from the beginning. It looks then safe, and helpful to backport this. Fixes: 4596a2c1b7f5 ("mptcp: allow creating non-backup subflows") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-07-30mptcp: distinguish rcv vs sent backup flag in requestsMatthieu Baerts (NGI0)1-0/+1
When sending an MP_JOIN + SYN + ACK, it is possible to mark the subflow as 'backup' by setting the flag with the same name. Before this patch, the backup was set if the other peer set it in its MP_JOIN + SYN request. It is not correct: the backup flag should be set in the MPJ+SYN+ACK only if the host asks for it, and not mirroring what was done by the other peer. It is then required to have a dedicated bit for each direction, similar to what is done in the subflow context. Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-06mptcp: refer to 'MPTCP' socket in commentsDavide Caratti1-1/+1
We used to call it 'master' socket at the early stages of MPTCP development, but the correct wording is 'MPTCP' socket opposed to 'TCP subflows': convert the last 3 comments to use a more appropriate term. Signed-off-by: Davide Caratti <dcaratti@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-13mptcp: remove unnecessary else statementsMatthieu Baerts (NGI0)1-15/+17
The 'else' statements are not needed here, because their previous 'if' block ends with a 'return'. This fixes CheckPatch warnings: WARNING: else is not generally useful after a break or return Reviewed-by: Geliang Tang <geliang@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20240514011335.176158-7-martineau@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-07mptcp: fix possible NULL dereferencesEric Dumazet1-15/+17
subflow_add_reset_reason(skb, ...) can fail. We can not assume mptcp_get_ext(skb) always return a non NULL pointer. syzbot reported: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] CPU: 0 PID: 5098 Comm: syz-executor132 Not tainted 6.9.0-rc6-syzkaller-01478-gcdc74c9d06e7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:subflow_v6_route_req+0x2c7/0x490 net/mptcp/subflow.c:388 Code: 8d 7b 07 48 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 c0 01 00 00 0f b6 43 07 48 8d 1c c3 48 83 c3 18 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 84 01 00 00 0f b6 5b 01 83 e3 0f 48 89 RSP: 0018:ffffc9000362eb68 EFLAGS: 00010206 RAX: 0000000000000003 RBX: 0000000000000018 RCX: ffff888022039e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88807d961140 R08: ffffffff8b6cb76b R09: 1ffff1100fb2c230 R10: dffffc0000000000 R11: ffffed100fb2c231 R12: dffffc0000000000 R13: ffff888022bfe273 R14: ffff88802cf9cc80 R15: ffff88802ad5a700 FS: 0000555587ad2380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f420c3f9720 CR3: 0000000022bfc000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> tcp_conn_request+0xf07/0x32c0 net/ipv4/tcp_input.c:7180 tcp_rcv_state_process+0x183c/0x4500 net/ipv4/tcp_input.c:6663 tcp_v6_do_rcv+0x8b2/0x1310 net/ipv6/tcp_ipv6.c:1673 tcp_v6_rcv+0x22b4/0x30b0 net/ipv6/tcp_ipv6.c:1910 ip6_protocol_deliver_rcu+0xc76/0x1570 net/ipv6/ip6_input.c:438 ip6_input_finish+0x186/0x2d0 net/ipv6/ip6_input.c:483 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5625 [inline] __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5739 netif_receive_skb_internal net/core/dev.c:5825 [inline] netif_receive_skb+0x1e8/0x890 net/core/dev.c:5885 tun_rx_batched+0x1b7/0x8f0 drivers/net/tun.c:1549 tun_get_user+0x2f35/0x4560 drivers/net/tun.c:2002 tun_chr_write_iter+0x113/0x1f0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2110 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa84/0xcb0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 3e140491dd80 ("mptcp: support rstreason for passive reset") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://lore.kernel.org/r/20240506123032.3351895-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-06mptcp: fix typos in commentsShi-Sheng Yang1-2/+2
This patch fixes the spelling mistakes in comments. The changes were generated using codespell and reviewed manually. eariler -> earlier greceful -> graceful Signed-off-by: Shi-Sheng Yang <fourcolor4c@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://lore.kernel.org/r/20240502154740.249839-1-fourcolor4c@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-26mptcp: introducing a helper into active reset logicJason Xing1-4/+2
Since we have mapped every mptcp reset reason definition in enum sk_rst_reason, introducing a new helper can cover some missing places where we have already set the subflow->reset_reason. Note: using SK_RST_REASON_NOT_SPECIFIED is the same as SK_RST_REASON_MPTCP_RST_EUNSPEC. They are both unknown. So we can convert it directly. Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-26mptcp: support rstreason for passive resetJason Xing1-5/+17
It relies on what reset options in the skb are as rfc8684 says. Reusing this logic can save us much energy. This patch replaces most of the prior NOT_SPECIFIED reasons. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-26rstreason: prepare for active resetJason Xing1-2/+3
Like what we did to passive reset: only passing possible reset reason in each active reset path. No functional changes. Signed-off-by: Jason Xing <kernelxing@tencent.com> Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-26rstreason: prepare for passive resetJason Xing1-3/+5
Adjust the parameter and support passing reason of reset which is for now NOT_SPECIFIED. No functional changes. Signed-off-by: Jason Xing <kernelxing@tencent.com> Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-09tcp: propagate tcp_tw_isn via an extra parameter to ->route_req()Eric Dumazet1-4/+6
tcp_v6_init_req() reads TCP_SKB_CB(skb)->tcp_tw_isn to find out if the request socket is created by a SYN hitting a TIMEWAIT socket. This has been buggy for a decade, lets directly pass the information from tcp_conn_request(). This is a preparatory patch to make the following one easier to review. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-08mptcp: add reset reason options in some placesJason Xing1-5/+15
The reason codes are handled in two ways nowadays (quoting Mat Martineau): 1. Sending in the MPTCP option on RST packets when there is no subflow context available (these use subflow_add_reset_reason() and directly call a TCP-level send_reset function) 2. The "normal" way via subflow->reset_reason. This will propagate to both the outgoing reset packet and to a local path manager process via netlink in mptcp_event_sub_closed() RFC 8684 defines the skb reset reason behaviour which is not required even though in some places: A host sends a TCP RST in order to close a subflow or reject an attempt to open a subflow (MP_JOIN). In order to let the receiving host know why a subflow is being closed or rejected, the TCP RST packet MAY include the MP_TCPRST option (Figure 15). The host MAY use this information to decide, for example, whether it tries to re-establish the subflow immediately, later, or never. Since the commit dc87efdb1a5cd ("mptcp: add mptcp reset option support") introduced this feature about three years ago, we can fully use it. There remains some places where we could insert reason into skb as we can see in this patch. Many thanks to Mat and Paolo for help:) Signed-off-by: Jason Xing <kernelxing@tencent.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-01mptcp: don't account accept() of non-MPC client as fallback to TCPDavide Caratti1-0/+2
Current MPTCP servers increment MPTcpExtMPCapableFallbackACK when they accept non-MPC connections. As reported by Christoph, this is "surprising" because the counter might become greater than MPTcpExtMPCapableSYNRX. MPTcpExtMPCapableFallbackACK counter's name suggests it should only be incremented when a connection was seen using MPTCP options, then a fallback to TCP has been done. Let's do that by incrementing it when the subflow context of an inbound MPC connection attempt is dropped. Also, update mptcp_connect.sh kselftest, to ensure that the above MIB does not increment in case a pure TCP client connects to a MPTCP server. Fixes: fc518953bc9c ("mptcp: add and use MIB counter infrastructure") Cc: stable@vger.kernel.org Reported-by: Christoph Paasch <cpaasch@apple.com> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/449 Signed-off-by: Davide Caratti <dcaratti@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://lore.kernel.org/r/20240329-upstream-net-20240329-fallback-mib-v1-1-324a8981da48@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-06mptcp: drop duplicate header inclusionsGeliang Tang1-2/+0
The headers net/tcp.h, net/genetlink.h and uapi/linux/mptcp.h are included in protocol.h already, no need to include them again directly. This patch removes these duplicate header inclusions. Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://lore.kernel.org/r/20240305-upstream-net-next-20240304-mptcp-misc-cleanup-v1-1-c436ba5e569b@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-7/+8
Cross-merge networking fixes after downstream PR. Conflicts: net/ipv4/udp.c f796feabb9f5 ("udp: add local "peek offset enabled" flag") 56667da7399e ("net: implement lockless setsockopt(SO_PEEK_OFF)") Adjacent changes: net/unix/garbage.c aa82ac51d633 ("af_unix: Drop oob_skb ref before purging queue in GC.") 11498715f266 ("af_unix: Remove io_uring code for GC.") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-18mptcp: fix data races on remote_idPaolo Abeni1-3/+3
Similar to the previous patch, address the data race on remote_id, adding the suitable ONCE annotations. Fixes: bedee0b56113 ("mptcp: address lookup improvements") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-18mptcp: fix data races on local_idPaolo Abeni1-4/+5
The local address id is accessed lockless by the NL PM, add all the required ONCE annotation. There is a caveat: the local id can be initialized late in the subflow life-cycle, and its validity is controlled by the local_id_valid flag. Remove such flag and encode the validity in the local_id field itself with negative value before initialization. That allows accessing the field consistently with a single read operation. Fixes: 0ee4261a3681 ("mptcp: implement mptcp_pm_remove_subflow") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-27/+44
Cross-merge networking fixes after downstream PR. No conflicts. Adjacent changes: net/core/dev.c 9f30831390ed ("net: add rcu safety to rtnl_prop_list_size()") 723de3ebef03 ("net: free altname using an RCU callback") net/unix/garbage.c 11498715f266 ("af_unix: Remove io_uring code for GC.") 25236c91b5ab ("af_unix: Fix task hung while purging oob_skb in GC.") drivers/net/ethernet/renesas/ravb_main.c ed4adc07207d ("net: ravb: Count packets instead of descriptors in GbEth RX path" ) c2da9408579d ("ravb: Add Rx checksum offload support for GbEth") net/mptcp/protocol.c bdd70eb68913 ("mptcp: drop the push_pending field") 28e5c1380506 ("mptcp: annotate lockless accesses around read-mostly fields") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-12mptcp: corner case locking for rx path fields initializationPaolo Abeni1-24/+32
Most MPTCP-level related fields are under the mptcp data lock protection, but are written one-off without such lock at MPC complete time, both for the client and the server Leverage the mptcp_propagate_state() infrastructure to move such initialization under the proper lock client-wise. The server side critical init steps are done by mptcp_subflow_fully_established(): ensure the caller properly held the relevant lock, and avoid acquiring the same lock in the nested scopes. There are no real potential races, as write access to such fields is implicitly serialized by the MPTCP state machine; the primary goal is consistency. Fixes: d22f4988ffec ("mptcp: process MP_CAPABLE data option") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-12mptcp: fix more tx path fields initializationPaolo Abeni1-2/+11
The 'msk->write_seq' and 'msk->snd_nxt' are always updated under the msk socket lock, except at MPC handshake completiont time. Builds-up on the previous commit to move such init under the relevant lock. There are no known problems caused by the potential race, the primary goal is consistency. Fixes: 6d0060f600ad ("mptcp: Write MPTCP DSS headers to outgoing data packets") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-12mptcp: fix rcv space initializationPaolo Abeni1-2/+2
mptcp_rcv_space_init() is supposed to happen under the msk socket lock, but active msk socket does that without such protection. Leverage the existing mptcp_propagate_state() helper to that extent. We need to ensure mptcp_rcv_space_init will happen before mptcp_rcv_space_adjust(), and the release_cb does not assure that: explicitly check for such condition. While at it, move the wnd_end initialization out of mptcp_rcv_space_init(), it never belonged there. Note that the race does not produce ill effect in practice, but change allows cleaning-up and defying better the locking model. Fixes: a6b118febbab ("mptcp: add receive buffer auto-tuning") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-05mptcp: annotate access for msk keysPaolo Abeni1-4/+6
Both the local and the remote key follow the same locking schema, put in place the proper ONCE accessors. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-01-17mptcp: relax check on MPC passive fallbackPaolo Abeni1-1/+2
While testing the blamed commit below, I was able to miss (!) packetdrill failures in the fastopen test-cases. On passive fastopen the child socket is created by incoming TCP MPC syn, allow for both MPC_SYN and MPC_ACK header. Fixes: 724b00c12957 ("mptcp: refine opt_mp_capable determination") Reviewed-by: Matthieu Baerts <matttbe@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-01-12mptcp: refine opt_mp_capable determinationEric Dumazet1-4/+4
OPTIONS_MPTCP_MPC is a combination of three flags. It would be better to be strict about testing what flag is expected, at least for code readability. mptcp_parse_option() already makes the distinction. - subflow_check_req() should use OPTION_MPTCP_MPC_SYN. - mptcp_subflow_init_cookie_req() should use OPTION_MPTCP_MPC_ACK. - subflow_finish_connect() should use OPTION_MPTCP_MPC_SYNACK - subflow_syn_recv_sock should use OPTION_MPTCP_MPC_ACK Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Fixes: 74c7dfbee3e1 ("mptcp: consolidate in_opt sub-options fields in a bitmask") Link: https://lore.kernel.org/r/20240111194917.4044654-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-12mptcp: use OPTION_MPTCP_MPJ_SYN in subflow_check_req()Eric Dumazet1-2/+2
syzbot reported that subflow_check_req() was using uninitialized data in subflow_check_req() [1] This is because mp_opt.token is only set when OPTION_MPTCP_MPJ_SYN is also set. While we are are it, fix mptcp_subflow_init_cookie_req() to test for OPTION_MPTCP_MPJ_ACK. [1] BUG: KMSAN: uninit-value in subflow_token_join_request net/mptcp/subflow.c:91 [inline] BUG: KMSAN: uninit-value in subflow_check_req+0x1028/0x15d0 net/mptcp/subflow.c:209 subflow_token_join_request net/mptcp/subflow.c:91 [inline] subflow_check_req+0x1028/0x15d0 net/mptcp/subflow.c:209 subflow_v6_route_req+0x269/0x410 net/mptcp/subflow.c:367 tcp_conn_request+0x153a/0x4240 net/ipv4/tcp_input.c:7164 subflow_v6_conn_request+0x3ee/0x510 tcp_rcv_state_process+0x2e1/0x4ac0 net/ipv4/tcp_input.c:6659 tcp_v6_do_rcv+0x11bf/0x1fe0 net/ipv6/tcp_ipv6.c:1669 tcp_v6_rcv+0x480b/0x4fb0 net/ipv6/tcp_ipv6.c:1900 ip6_protocol_deliver_rcu+0xda6/0x2a60 net/ipv6/ip6_input.c:438 ip6_input_finish net/ipv6/ip6_input.c:483 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492 dst_input include/net/dst.h:461 [inline] ip6_rcv_finish+0x5db/0x870 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:314 [inline] ipv6_rcv+0xda/0x390 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core net/core/dev.c:5532 [inline] __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5646 netif_receive_skb_internal net/core/dev.c:5732 [inline] netif_receive_skb+0x58/0x660 net/core/dev.c:5791 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555 tun_get_user+0x53af/0x66d0 drivers/net/tun.c:2002 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2020 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x8ef/0x1490 fs/read_write.c:584 ksys_write+0x20f/0x4c0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Local variable mp_opt created at: subflow_check_req+0x6d/0x15d0 net/mptcp/subflow.c:145 subflow_v6_route_req+0x269/0x410 net/mptcp/subflow.c:367 CPU: 1 PID: 5924 Comm: syz-executor.3 Not tainted 6.7.0-rc8-syzkaller-00055-g5eff55d725a4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Cc: Peter Krystad <peter.krystad@linux.intel.com> Cc: Matthieu Baerts <matttbe@kernel.org> Cc: Mat Martineau <martineau@kernel.org> Cc: Geliang Tang <geliang.tang@linux.dev> Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20240111194917.4044654-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-12mptcp: use OPTION_MPTCP_MPJ_SYNACK in subflow_finish_connect()Eric Dumazet1-1/+1
subflow_finish_connect() uses four fields (backup, join_id, thmac, none) that may contain garbage unless OPTION_MPTCP_MPJ_SYNACK has been set in mptcp_parse_option() Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Cc: Peter Krystad <peter.krystad@linux.intel.com> Cc: Matthieu Baerts <matttbe@kernel.org> Cc: Mat Martineau <martineau@kernel.org> Cc: Geliang Tang <geliang.tang@linux.dev> Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20240111194917.4044654-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-12mptcp: strict validation before using mp_opt->hmacEric Dumazet1-1/+1
mp_opt->hmac contains uninitialized data unless OPTION_MPTCP_MPJ_ACK was set in mptcp_parse_option(). We must refine the condition before we call subflow_hmac_valid(). Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Cc: Peter Krystad <peter.krystad@linux.intel.com> Cc: Matthieu Baerts <matttbe@kernel.org> Cc: Mat Martineau <martineau@kernel.org> Cc: Geliang Tang <geliang.tang@linux.dev> Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20240111194917.4044654-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-0/+13
Cross-merge networking fixes after downstream PR. Conflicts: drivers/net/ethernet/broadcom/bnxt/bnxt.c e009b2efb7a8 ("bnxt_en: Remove mis-applied code from bnxt_cfg_ntp_filters()") 0f2b21477988 ("bnxt_en: Fix compile error without CONFIG_RFS_ACCEL") https://lore.kernel.org/all/20240105115509.225aa8a2@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-02mptcp: prevent tcp diag from closing listener subflowsPaolo Abeni1-0/+13
The MPTCP protocol does not expect that any other entity could change the first subflow status when such socket is listening. Unfortunately the TCP diag interface allows aborting any TCP socket, including MPTCP listeners subflows. As reported by syzbot, that trigger a WARN() and could lead to later bigger trouble. The MPTCP protocol needs to do some MPTCP-level cleanup actions to properly shutdown the listener. To keep the fix simple, prevent entirely the diag interface from stopping such listeners. We could refine the diag callback in a later, larger patch targeting net-next. Fixes: 57fc0f1ceaa4 ("mptcp: ensure listener is unhashed before updating the sk status") Cc: stable@vger.kernel.org Reported-by: <syzbot+5a01c3a666e726bc8752@syzkaller.appspotmail.com> Closes: https://lore.kernel.org/netdev/0000000000004f4579060c68431b@google.com/ Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matttbe@kernel.org> Link: https://lore.kernel.org/r/20231226-upstream-net-20231226-mptcp-prevent-warn-v1-2-1404dcc431ea@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-02mptcp: use mptcp_set_stateGeliang Tang1-1/+1
This patch replaces all the 'inet_sk_state_store()' calls under net/mptcp with the new helper mptcp_set_state(). Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/460 Signed-off-by: Geliang Tang <geliang.tang@linux.dev> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matttbe@kernel.org> Signed-off-by: Matthieu Baerts <matttbe@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-17mptcp: fix inconsistent state on fastopen racePaolo Abeni1-11/+17
The netlink PM can race with fastopen self-connect attempts, shutting down the first subflow via: MPTCP_PM_CMD_DEL_ADDR -> mptcp_nl_remove_id_zero_address -> mptcp_pm_nl_rm_subflow_received -> mptcp_close_ssk and transitioning such subflow to FIN_WAIT1 status before the syn-ack packet is processed. The MPTCP code does not react to such state change, leaving the connection in not-fallback status and the subflow handshake uncompleted, triggering the following splat: WARNING: CPU: 0 PID: 10630 at net/mptcp/subflow.c:1405 subflow_data_ready+0x39f/0x690 net/mptcp/subflow.c:1405 Modules linked in: CPU: 0 PID: 10630 Comm: kworker/u4:11 Not tainted 6.6.0-syzkaller-14500-g1c41041124bd #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Workqueue: bat_events batadv_nc_worker RIP: 0010:subflow_data_ready+0x39f/0x690 net/mptcp/subflow.c:1405 Code: 18 89 ee e8 e3 d2 21 f7 40 84 ed 75 1f e8 a9 d7 21 f7 44 89 fe bf 07 00 00 00 e8 0c d3 21 f7 41 83 ff 07 74 07 e8 91 d7 21 f7 <0f> 0b e8 8a d7 21 f7 48 89 df e8 d2 b2 ff ff 31 ff 89 c5 89 c6 e8 RSP: 0018:ffffc90000007448 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff888031efc700 RCX: ffffffff8a65baf4 RDX: ffff888043222140 RSI: ffffffff8a65baff RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000007 R10: 000000000000000b R11: 0000000000000000 R12: 1ffff92000000e89 R13: ffff88807a534d80 R14: ffff888021c11a00 R15: 000000000000000b FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa19a0ffc81 CR3: 000000007a2db000 CR4: 00000000003506f0 DR0: 000000000000d8dd DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: <IRQ> tcp_data_ready+0x14c/0x5b0 net/ipv4/tcp_input.c:5128 tcp_data_queue+0x19c3/0x5190 net/ipv4/tcp_input.c:5208 tcp_rcv_state_process+0x11ef/0x4e10 net/ipv4/tcp_input.c:6844 tcp_v4_do_rcv+0x369/0xa10 net/ipv4/tcp_ipv4.c:1929 tcp_v4_rcv+0x3888/0x3b30 net/ipv4/tcp_ipv4.c:2329 ip_protocol_deliver_rcu+0x9f/0x480 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2e4/0x510 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_local_deliver+0x1b6/0x550 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:461 [inline] ip_rcv_finish+0x1c4/0x2e0 net/ipv4/ip_input.c:449 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_rcv+0xce/0x440 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core+0x115/0x180 net/core/dev.c:5527 __netif_receive_skb+0x1f/0x1b0 net/core/dev.c:5641 process_backlog+0x101/0x6b0 net/core/dev.c:5969 __napi_poll.constprop.0+0xb4/0x540 net/core/dev.c:6531 napi_poll net/core/dev.c:6600 [inline] net_rx_action+0x956/0xe90 net/core/dev.c:6733 __do_softirq+0x21a/0x968 kernel/softirq.c:553 do_softirq kernel/softirq.c:454 [inline] do_softirq+0xaa/0xe0 kernel/softirq.c:441 </IRQ> <TASK> __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:381 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_nc_purge_paths+0x1ce/0x3c0 net/batman-adv/network-coding.c:471 batadv_nc_worker+0x9b1/0x10e0 net/batman-adv/network-coding.c:722 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 </TASK> To address the issue, catch the racing subflow state change and use it to cause the MPTCP fallback. Such fallback is also used to cause the first subflow state propagation to the msk socket via mptcp_set_connected(). After this change, the first subflow can additionally propagate the TCP_FIN_WAIT1 state, so rename the helper accordingly. Finally, if the state propagation is delayed to the msk release callback, the first subflow can change to a different state in between. Cache the relevant target state in a new msk-level field and use such value to update the msk state at release time. Fixes: 1e777f39b4d7 ("mptcp: add MSG_FASTOPEN sendmsg flag support") Cc: stable@vger.kernel.org Reported-by: <syzbot+c53d4d3ddb327e80bc51@syzkaller.appspotmail.com> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/458 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matttbe@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-02Merge tag 'v6.7-p1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto updates from Herbert Xu: "API: - Add virtual-address based lskcipher interface - Optimise ahash/shash performance in light of costly indirect calls - Remove ahash alignmask attribute Algorithms: - Improve AES/XTS performance of 6-way unrolling for ppc - Remove some uses of obsolete algorithms (md4, md5, sha1) - Add FIPS 202 SHA-3 support in pkcs1pad - Add fast path for single-page messages in adiantum - Remove zlib-deflate Drivers: - Add support for S4 in meson RNG driver - Add STM32MP13x support in stm32 - Add hwrng interface support in qcom-rng - Add support for deflate algorithm in hisilicon/zip" * tag 'v6.7-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (283 commits) crypto: adiantum - flush destination page before unmapping crypto: testmgr - move pkcs1pad(rsa,sha3-*) to correct place Documentation/module-signing.txt: bring up to date module: enable automatic module signing with FIPS 202 SHA-3 crypto: asymmetric_keys - allow FIPS 202 SHA-3 signatures crypto: rsa-pkcs1pad - Add FIPS 202 SHA-3 support crypto: FIPS 202 SHA-3 register in hash info for IMA x509: Add OIDs for FIPS 202 SHA-3 hash and signatures crypto: ahash - optimize performance when wrapping shash crypto: ahash - check for shash type instead of not ahash type crypto: hash - move "ahash wrapping shash" functions to ahash.c crypto: talitos - stop using crypto_ahash::init crypto: chelsio - stop using crypto_ahash::init crypto: ahash - improve file comment crypto: ahash - remove struct ahash_request_priv crypto: ahash - remove crypto_ahash_alignmask crypto: gcm - stop using alignmask of ahash crypto: chacha20poly1305 - stop using alignmask of ahash crypto: ccm - stop using alignmask of ahash net: ipv6: stop checking crypto_ahash_alignmask ...
2023-10-25ipv6: drop feature RTAX_FEATURE_ALLFRAGYan Zhai1-1/+0
RTAX_FEATURE_ALLFRAG was added before the first git commit: https://www.mail-archive.com/bk-commits-head@vger.kernel.org/msg03399.html The feature would send packets to the fragmentation path if a box receives a PMTU value with less than 1280 byte. However, since commit 9d289715eb5c ("ipv6: stop sending PTB packets for MTU < 1280"), such message would be simply discarded. The feature flag is neither supported in iproute2 utility. In theory one can still manipulate it with direct netlink message, but it is not ideal because it was based on obsoleted guidance of RFC-2460 (replaced by RFC-8200). The feature would always test false at the moment, so remove related code or mark them as unused. Signed-off-by: Yan Zhai <yan@cloudflare.com> Reviewed-by: Florian Westphal <fw@strlen.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/d78e44dcd9968a252143ffe78460446476a472a1.1698156966.git.yan@cloudflare.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-25mptcp: refactor sndbuf auto-tuningPaolo Abeni1-2/+1
The MPTCP protocol account for the data enqueued on all the subflows to the main socket send buffer, while the send buffer auto-tuning algorithm set the main socket send buffer size as the max size among the subflows. That causes bad performances when at least one subflow is sndbuf limited, e.g. due to very high latency, as the MPTCP scheduler can't even fill such buffer. Change the send-buffer auto-tuning algorithm to compute the main socket send buffer size as the sum of all the subflows buffer size. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20231023-send-net-next-20231023-2-v1-9-9dc60939d371@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-25mptcp: consolidate sockopt synchronizationPaolo Abeni1-9/+9
Move the socket option synchronization for active subflows at subflow creation time. This allows removing the now unused unlocked variant of such helper. While at that, clean-up a bit the mptcp_subflow_create_socket() errors path. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20231023-send-net-next-20231023-2-v1-7-9dc60939d371@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-25mptcp: give rcvlowat some lovePaolo Abeni1-2/+10
The MPTCP protocol allow setting sk_rcvlowat, but the value there is currently ignored. Additionally, the default subflows sk_rcvlowat basically disables per subflow delayed ack: the MPTCP protocol move the incoming data from the subflows into the msk socket as soon as the TCP stacks invokes the subflow data_ready callback. Later, when __tcp_ack_snd_check() takes action, the subflow-level copied_seq matches rcv_nxt, and that mandate for an immediate ack. Let the mptcp receive path be aware of such threshold, explicitly tracking the amount of data available to be ready and checking vs sk_rcvlowat in mptcp_poll() and before waking-up readers. Additionally implement the set_rcvlowat() callback, to properly handle the rcvbuf auto-tuning on sk_rcvlowat changes. Finally to properly handle delayed ack, force the subflow level threshold to 0 and instead explicitly ask for an immediate ack when the msk level th is not reached. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20231023-send-net-next-20231023-2-v1-5-9dc60939d371@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-25mptcp: use plain bool instead of custom binary enumPaolo Abeni1-6/+6
The 'data_avail' subflow field is already used as plain boolean, drop the custom binary enum type and switch to bool. No functional changed intended. Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20231023-send-net-next-20231023-2-v1-3-9dc60939d371@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-05mptcp: fix delegated action racesPaolo Abeni1-2/+8
The delegated action infrastructure is prone to the following race: different CPUs can try to schedule different delegated actions on the same subflow at the same time. Each of them will check different bits via mptcp_subflow_delegate(), and will try to schedule the action on the related per-cpu napi instance. Depending on the timing, both can observe an empty delegated list node, causing the same entry to be added simultaneously on two different lists. The root cause is that the delegated actions infra does not provide a single synchronization point. Address the issue reserving an additional bit to mark the subflow as scheduled for delegation. Acquiring such bit guarantee the caller to own the delegated list node, and being able to safely schedule the subflow. Clear such bit only when the subflow scheduling is completed, ensuring proper barrier in place. Additionally swap the meaning of the delegated_action bitmask, to allow the usage of the existing helper to set multiple bit at once. Fixes: bcd97734318d ("mptcp: use delegate action to schedule 3rd ack retrans") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20231004-send-net-20231004-v1-1-28de4ac663ae@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-09-18mptcp: fix dangling connection hang-upPaolo Abeni1-0/+1
According to RFC 8684 section 3.3: A connection is not closed unless [...] or an implementation-specific connection-level send timeout. Currently the MPTCP protocol does not implement such timeout, and connection timing-out at the TCP-level never move to close state. Introduces a catch-up condition at subflow close time to move the MPTCP socket to close, too. That additionally allows removing similar existing inside the worker. Finally, allow some additional timeout for plain ESTABLISHED mptcp sockets, as the protocol allows creating new subflows even at that point and making the connection functional again. This issue is actually present since the beginning, but it is basically impossible to solve without a long chain of functional pre-requisites topped by commit bbd49d114d57 ("mptcp: consolidate transition to TCP_CLOSE in mptcp_do_fastclose()"). When backporting this current patch, please also backport this other commit as well. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/430 Fixes: e16163b6e2b7 ("mptcp: refactor shutdown and close") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-18mptcp: rename timer related helper to less confusing namesPaolo Abeni1-1/+1
The msk socket uses to different timeout to track close related events and retransmissions. The existing helpers do not indicate clearly which timer they actually touch, making the related code quite confusing. Change the existing helpers name to avoid such confusion. No functional change intended. This patch is linked to the next one ("mptcp: fix dangling connection hang-up"). The two patches are supposed to be backported together. Cc: stable@vger.kernel.org # v5.11+ Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
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