BMC/Intel-BMC/linux.git/net/mptcp, branch dev-5.10-intel

mptcp: fix warning in __skb_flow_dissect() when do syn cookie for subflow join

2021-07-28T12:35:34+00:00

[ Upstream commit 0c71929b5893e410e0efbe1bbeca6f19a5f19956 ] I did stress test with wrk[1] and webfsd[2] with the assistance of mptcp-tools[3]: Server side: ./use_mptcp.sh webfsd -4 -R /tmp/ -p 8099 Client side: ./use_mptcp.sh wrk -c 200 -d 30 -t 4 http://192.168.174.129:8099/ and got the following warning message: [ 55.552626] TCP: request_sock_subflow: Possible SYN flooding on port 8099. Sending cookies. Check SNMP counters. [ 55.553024] ------------[ cut here ]------------ [ 55.553027] WARNING: CPU: 0 PID: 10 at net/core/flow_dissector.c:984 __skb_flow_dissect+0x280/0x1650 ... [ 55.553117] CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.12.0+ #18 [ 55.553121] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 02/27/2020 [ 55.553124] RIP: 0010:__skb_flow_dissect+0x280/0x1650 ... [ 55.553133] RSP: 0018:ffffb79580087770 EFLAGS: 00010246 [ 55.553137] RAX: 0000000000000000 RBX: ffffffff8ddb58e0 RCX: ffffb79580087888 [ 55.553139] RDX: ffffffff8ddb58e0 RSI: ffff8f7e4652b600 RDI: 0000000000000000 [ 55.553141] RBP: ffffb79580087858 R08: 0000000000000000 R09: 0000000000000008 [ 55.553143] R10: 000000008c622965 R11: 00000000d3313a5b R12: ffff8f7e4652b600 [ 55.553146] R13: ffff8f7e465c9062 R14: 0000000000000000 R15: ffffb79580087888 [ 55.553149] FS: 0000000000000000(0000) GS:ffff8f7f75e00000(0000) knlGS:0000000000000000 [ 55.553152] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 55.553154] CR2: 00007f73d1d19000 CR3: 0000000135e10004 CR4: 00000000003706f0 [ 55.553160] Call Trace: [ 55.553166] ? __sha256_final+0x67/0xd0 [ 55.553173] ? sha256+0x7e/0xa0 [ 55.553177] __skb_get_hash+0x57/0x210 [ 55.553182] subflow_init_req_cookie_join_save+0xac/0xc0 [ 55.553189] subflow_check_req+0x474/0x550 [ 55.553195] ? ip_route_output_key_hash+0x67/0x90 [ 55.553200] ? xfrm_lookup_route+0x1d/0xa0 [ 55.553207] subflow_v4_route_req+0x8e/0xd0 [ 55.553212] tcp_conn_request+0x31e/0xab0 [ 55.553218] ? selinux_socket_sock_rcv_skb+0x116/0x210 [ 55.553224] ? tcp_rcv_state_process+0x179/0x6d0 [ 55.553229] tcp_rcv_state_process+0x179/0x6d0 [ 55.553235] tcp_v4_do_rcv+0xaf/0x220 [ 55.553239] tcp_v4_rcv+0xce4/0xd80 [ 55.553243] ? ip_route_input_rcu+0x246/0x260 [ 55.553248] ip_protocol_deliver_rcu+0x35/0x1b0 [ 55.553253] ip_local_deliver_finish+0x44/0x50 [ 55.553258] ip_local_deliver+0x6c/0x110 [ 55.553262] ? ip_rcv_finish_core.isra.19+0x5a/0x400 [ 55.553267] ip_rcv+0xd1/0xe0 ... After debugging, I found in __skb_flow_dissect(), skb->dev and skb->sk are both NULL, then net is NULL, and trigger WARN_ON_ONCE(!net), actually net is always NULL in this code path, as skb->dev is set to NULL in tcp_v4_rcv(), and skb->sk is never set. Code snippet in __skb_flow_dissect() that trigger warning: 975 if (skb) { 976 if (!net) { 977 if (skb->dev) 978 net = dev_net(skb->dev); 979 else if (skb->sk) 980 net = sock_net(skb->sk); 981 } 982 } 983 984 WARN_ON_ONCE(!net); So, using seq and transport header derived hash. [1] https://github.com/wg/wrk [2] https://github.com/ourway/webfsd [3] https://github.com/pabeni/mptcp-tools Fixes: 9466a1ccebbe ("mptcp: enable JOIN requests even if cookies are in use") Suggested-by: Paolo Abeni Suggested-by: Florian Westphal Signed-off-by: Jianguo Wu Signed-off-by: Mat Martineau Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

mptcp: generate subflow hmac after mptcp_finish_join()

2021-07-14T14:56:17+00:00

[ Upstream commit 0a4d8e96e4fd687af92b961d5cdcea0fdbde05fe ] For outgoing subflow join, when recv SYNACK, in subflow_finish_connect(), the mptcp_finish_join() may return false in some cases, and send a RESET to remote, and no local hmac is required. So generate subflow hmac after mptcp_finish_join(). Fixes: ec3edaa7ca6c ("mptcp: Add handling of outgoing MP_JOIN requests") Signed-off-by: Jianguo Wu Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

mptcp: fix pr_debug in mptcp_token_new_connect

2021-07-14T14:56:17+00:00

[ Upstream commit 2f1af441fd5dd5caf0807bb19ce9bbf9325ce534 ] After commit 2c5ebd001d4f ("mptcp: refactor token container"), pr_debug() is called before mptcp_crypto_key_gen_sha() in mptcp_token_new_connect(), so the output local_key, token and idsn are 0, like: MPTCP: ssk=00000000f6b3c4a2, local_key=0, token=0, idsn=0 Move pr_debug() after mptcp_crypto_key_gen_sha(). Fixes: 2c5ebd001d4f ("mptcp: refactor token container") Acked-by: Paolo Abeni Signed-off-by: Jianguo Wu Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

mptcp: do not warn on bad input from the network

2021-06-23T12:42:43+00:00

[ Upstream commit 61e710227e97172355d5f150d5c78c64175d9fb2 ] warn_bad_map() produces a kernel WARN on bad input coming from the network. Use pr_debug() to avoid spamming the system log. Additionally, when the right bound check fails, warn_bad_map() reports the wrong ssn value, let's fix it. Fixes: 648ef4b88673 ("mptcp: Implement MPTCP receive path") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/107 Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

mptcp: try harder to borrow memory from subflow under pressure

2021-06-23T12:42:43+00:00

[ Upstream commit 72f961320d5d15bfcb26dbe3edaa3f7d25fd2c8a ] If the host is under sever memory pressure, and RX forward memory allocation for the msk fails, we try to borrow the required memory from the ingress subflow. The current attempt is a bit flaky: if skb->truesize is less than SK_MEM_QUANTUM, the ssk will not release any memory, and the next schedule will fail again. Instead, directly move the required amount of pages from the ssk to the msk, if available Fixes: 9c3f94e1681b ("mptcp: add missing memory scheduling in the rx path") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

mptcp: Fix out of bounds when parsing TCP options

2021-06-23T12:42:43+00:00

[ Upstream commit 07718be265680dcf496347d475ce1a5442f55ad7 ] The TCP option parser in mptcp (mptcp_get_options) could read one byte out of bounds. When the length is 1, the execution flow gets into the loop, reads one byte of the opcode, and if the opcode is neither TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds the length of 1. This fix is inspired by commit 9609dad263f8 ("ipv4: tcp_input: fix stack out of bounds when parsing TCP options."). Cc: Young Xiao <92siuyang@gmail.com> Fixes: cec37a6e41aa ("mptcp: Handle MP_CAPABLE options for outgoing connections") Signed-off-by: Maxim Mikityanskiy Reviewed-by: Mat Martineau Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

mptcp: always parse mptcp options for MPC reqsk

2021-06-10T11:39:16+00:00

[ Upstream commit 06f9a435b3aa12f4de6da91f11fdce8ce7b46205 ] In subflow_syn_recv_sock() we currently skip options parsing for OoO packet, given that such packets may not carry the relevant MPC option. If the peer generates an MPC+data TSO packet and some of the early segments are lost or get reorder, we server will ignore the peer key, causing transient, unexpected fallback to TCP. The solution is always parsing the incoming MPTCP options, and do the fallback only for in-order packets. This actually cleans the existing code a bit. Fixes: d22f4988ffec ("mptcp: process MP_CAPABLE data option") Reported-by: Matthieu Baerts Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

mptcp: fix data stream corruption

2021-06-03T07:00:39+00:00

commit 29249eac5225429b898f278230a6ca2baa1ae154 upstream. Maxim reported several issues when forcing a TCP transparent proxy to use the MPTCP protocol for the inbound connections. He also provided a clean reproducer. The problem boils down to 'mptcp_frag_can_collapse_to()' assuming that only MPTCP will use the given page_frag. If others - e.g. the plain TCP protocol - allocate page fragments, we can end-up re-using already allocated memory for mptcp_data_frag. Fix the issue ensuring that the to-be-expanded data fragment is located at the current page frag end. v1 -> v2: - added missing fixes tag (Mat) Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/178 Reported-and-tested-by: Maxim Galaganov Fixes: 18b683bff89d ("mptcp: queue data for mptcp level retransmission") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

mptcp: drop unconditional pr_warn on bad opt

2021-06-03T07:00:39+00:00

commit 3812ce895047afdb78dc750a236515416e0ccded upstream. This is a left-over of early day. A malicious peer can flood the kernel logs with useless messages, just drop it. Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

mptcp: avoid error message on infinite mapping

2021-06-03T07:00:39+00:00

commit 3ed0a585bfadb6bd7080f11184adbc9edcce7dbc upstream. Another left-over. Avoid flooding dmesg with useless text, we already have a MIB for that event. Fixes: 648ef4b88673 ("mptcp: Implement MPTCP receive path") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman