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2021-10-08mptcp: fix possible stall on recvmsg()Paolo Abeni1-40/+15
recvmsg() can enter an infinite loop if the caller provides the MSG_WAITALL, the data present in the receive queue is not sufficient to fulfill the request, and no more data is received by the peer. When the above happens, mptcp_wait_data() will always return with no wait, as the MPTCP_DATA_READY flag checked by such function is set and never cleared in such code path. Leveraging the above syzbot was able to trigger an RCU stall: rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=0af/1/0x4000000000000000 softirq=10678/10678 fqs=1 (t=10500 jiffies g=13089 q=109) rcu: rcu_preempt kthread starved for 10497 jiffies! g13089 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:28696 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4955 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6236 schedule+0xd3/0x270 kernel/sched/core.c:6315 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8510 Comm: syz-executor827 Not tainted 5.15.0-rc2-next-20210920-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:84 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0xc8/0x180 mm/kasan/generic.c:189 Code: 38 00 74 ed 48 8d 50 08 eb 09 48 83 c0 01 48 39 d0 74 7a 80 38 00 74 f2 48 89 c2 b8 01 00 00 00 48 85 d2 75 56 5b 5d 41 5c c3 <48> 85 d2 74 5e 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 50 80 38 00 RSP: 0018:ffffc9000cd676c8 EFLAGS: 00000283 RAX: ffffed100e9a110e RBX: ffffed100e9a110f RCX: ffffffff88ea062a RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff888074d08870 RBP: ffffed100e9a110e R08: 0000000000000001 R09: ffff888074d08877 R10: ffffed100e9a110e R11: 0000000000000000 R12: ffff888074d08000 R13: ffff888074d08000 R14: ffff888074d08088 R15: ffff888074d08000 FS: 0000555556d8e300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 S: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000180 CR3: 0000000068909000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:101 [inline] test_and_clear_bit include/asm-generic/bitops/instrumented-atomic.h:83 [inline] mptcp_release_cb+0x14a/0x210 net/mptcp/protocol.c:3016 release_sock+0xb4/0x1b0 net/core/sock.c:3204 mptcp_wait_data net/mptcp/protocol.c:1770 [inline] mptcp_recvmsg+0xfd1/0x27b0 net/mptcp/protocol.c:2080 inet6_recvmsg+0x11b/0x5e0 net/ipv6/af_inet6.c:659 sock_recvmsg_nosec net/socket.c:944 [inline] ____sys_recvmsg+0x527/0x600 net/socket.c:2626 ___sys_recvmsg+0x127/0x200 net/socket.c:2670 do_recvmmsg+0x24d/0x6d0 net/socket.c:2764 __sys_recvmmsg net/socket.c:2843 [inline] __do_sys_recvmmsg net/socket.c:2866 [inline] __se_sys_recvmmsg net/socket.c:2859 [inline] __x64_sys_recvmmsg+0x20b/0x260 net/socket.c:2859 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc200d2dc39 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc5758e5a8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fc200d2dc39 RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000f0b5ff R10: 0000000000000100 R11: 0000000000000246 R12: 0000000000000003 R13: 00007ffc5758e5d0 R14: 00007ffc5758e5c0 R15: 0000000000000003 Fix the issue by replacing the MPTCP_DATA_READY bit with direct inspection of the msk receive queue. Reported-and-tested-by: syzbot+3360da629681aa0d22fe@syzkaller.appspotmail.com Fixes: 7a6a6cbc3e59 ("mptcp: recvmsg() can drain data from multiple subflow") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-30net: introduce and use lock_sock_fast_nested()Paolo Abeni1-1/+1
Syzkaller reported a false positive deadlock involving the nl socket lock and the subflow socket lock: MPTCP: kernel_bind error, err=-98 ============================================ WARNING: possible recursive locking detected 5.15.0-rc1-syzkaller #0 Not tainted -------------------------------------------- syz-executor998/6520 is trying to acquire lock: ffff8880795718a0 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x267/0x7b0 net/mptcp/protocol.c:2738 but task is already holding lock: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline] ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x23/0x7b0 net/mptcp/protocol.c:2720 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(k-sk_lock-AF_INET); lock(k-sk_lock-AF_INET); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by syz-executor998/6520: #0: ffffffff8d176c50 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802 #1: ffffffff8d176d08 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8d176d08 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x3e0/0x580 net/netlink/genetlink.c:790 #2: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline] #2: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x23/0x7b0 net/mptcp/protocol.c:2720 stack backtrace: CPU: 1 PID: 6520 Comm: syz-executor998 Not tainted 5.15.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2944 [inline] check_deadlock kernel/locking/lockdep.c:2987 [inline] validate_chain kernel/locking/lockdep.c:3776 [inline] __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 lock_sock_fast+0x36/0x100 net/core/sock.c:3229 mptcp_close+0x267/0x7b0 net/mptcp/protocol.c:2738 inet_release+0x12e/0x280 net/ipv4/af_inet.c:431 __sock_release net/socket.c:649 [inline] sock_release+0x87/0x1b0 net/socket.c:677 mptcp_pm_nl_create_listen_socket+0x238/0x2c0 net/mptcp/pm_netlink.c:900 mptcp_nl_cmd_add_addr+0x359/0x930 net/mptcp/pm_netlink.c:1170 genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:731 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 sock_no_sendpage+0x101/0x150 net/core/sock.c:2980 kernel_sendpage.part.0+0x1a0/0x340 net/socket.c:3504 kernel_sendpage net/socket.c:3501 [inline] sock_sendpage+0xe5/0x140 net/socket.c:1003 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x43e/0x8a0 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:746 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0xae9/0x1240 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1314 [inline] __se_sys_sendfile64 fs/read_write.c:1300 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1300 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f215cb69969 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc96bb3868 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f215cbad072 RCX: 00007f215cb69969 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005 RBP: 0000000000000000 R08: 00007ffc96bb3a08 R09: 00007ffc96bb3a08 R10: 0000000100000002 R11: 0000000000000246 R12: 00007ffc96bb387c R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000 the problem originates from uncorrect lock annotation in the mptcp code and is only visible since commit 2dcb96bacce3 ("net: core: Correct the sock::sk_lock.owned lockdep annotations"), but is present since the port-based endpoint support initial implementation. This patch addresses the issue introducing a nested variant of lock_sock_fast() and using it in the relevant code path. Fixes: 1729cf186d8a ("mptcp: create the listening socket for new port") Fixes: 2dcb96bacce3 ("net: core: Correct the sock::sk_lock.owned lockdep annotations") Suggested-by: Thomas Gleixner <tglx@linutronix.de> Reported-and-tested-by: syzbot+1dd53f7a89b299d59eaf@syzkaller.appspotmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-24mptcp: allow changing the 'backup' bit when no sockets are openDavide Caratti1-3/+1
current Linux refuses to change the 'backup' bit of MPTCP endpoints, i.e. using MPTCP_PM_CMD_SET_FLAGS, unless it finds (at least) one subflow that matches the endpoint address. There is no reason for that, so we can just ignore the return value of mptcp_nl_addr_backup(). In this way, endpoints can reconfigure their 'backup' flag even if no MPTCP sockets are open (or more generally, in case the MP_PRIO message is not sent out). Fixes: 0f9f696a502e ("mptcp: add set_flags command in PM netlink") Signed-off-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-24mptcp: don't return sockets in foreign netnsFlorian Westphal6-24/+20
mptcp_token_get_sock() may return a mptcp socket that is in a different net namespace than the socket that received the token value. The mptcp syncookie code path had an explicit check for this, this moves the test into mptcp_token_get_sock() function. Eventually token.c should be converted to pernet storage, but such change is not suitable for net tree. Fixes: 2c5ebd001d4f0 ("mptcp: refactor token container") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-22mptcp: ensure tx skbs always have the MPTCP extPaolo Abeni1-2/+2
Due to signed/unsigned comparison, the expression: info->size_goal - skb->len > 0 evaluates to true when the size goal is smaller than the skb size. That results in lack of tx cache refill, so that the skb allocated by the core TCP code lacks the required MPTCP skb extensions. Due to the above, syzbot is able to trigger the following WARN_ON(): WARNING: CPU: 1 PID: 810 at net/mptcp/protocol.c:1366 mptcp_sendmsg_frag+0x1362/0x1bc0 net/mptcp/protocol.c:1366 Modules linked in: CPU: 1 PID: 810 Comm: syz-executor.4 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mptcp_sendmsg_frag+0x1362/0x1bc0 net/mptcp/protocol.c:1366 Code: ff 4c 8b 74 24 50 48 8b 5c 24 58 e9 0f fb ff ff e8 13 44 8b f8 4c 89 e7 45 31 ed e8 98 57 2e fe e9 81 f4 ff ff e8 fe 43 8b f8 <0f> 0b 41 bd ea ff ff ff e9 6f f4 ff ff 4c 89 e7 e8 b9 8e d2 f8 e9 RSP: 0018:ffffc9000531f6a0 EFLAGS: 00010216 RAX: 000000000000697f RBX: 0000000000000000 RCX: ffffc90012107000 RDX: 0000000000040000 RSI: ffffffff88eac9e2 RDI: 0000000000000003 RBP: ffff888078b15780 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff88eac017 R11: 0000000000000000 R12: ffff88801de0a280 R13: 0000000000006b58 R14: ffff888066278280 R15: ffff88803c2fe9c0 FS: 00007fd9f866e700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faebcb2f718 CR3: 00000000267cb000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __mptcp_push_pending+0x1fb/0x6b0 net/mptcp/protocol.c:1547 mptcp_release_cb+0xfe/0x210 net/mptcp/protocol.c:3003 release_sock+0xb4/0x1b0 net/core/sock.c:3206 sk_stream_wait_memory+0x604/0xed0 net/core/stream.c:145 mptcp_sendmsg+0xc39/0x1bc0 net/mptcp/protocol.c:1749 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:643 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 sock_write_iter+0x2a0/0x3e0 net/socket.c:1057 call_write_iter include/linux/fs.h:2163 [inline] new_sync_write+0x40b/0x640 fs/read_write.c:507 vfs_write+0x7cf/0xae0 fs/read_write.c:594 ksys_write+0x1ee/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd9f866e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665f9 RDX: 00000000000e7b78 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 0000000000a9fb1f R14: 00007fd9f866e300 R15: 0000000000022000 Fix the issue rewriting the relevant expression to avoid sign-related problems - note: size_goal is always >= 0. Additionally, ensure that the skb in the tx cache always carries the relevant extension. Reported-and-tested-by: syzbot+263a248eec3e875baa7b@syzkaller.appspotmail.com Fixes: 1094c6fe7280 ("mptcp: fix possible divide by zero") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-03mptcp: Only send extra TCP acks in eligible socket statesMat Martineau3-17/+15
Recent changes exposed a bug where specifically-timed requests to the path manager netlink API could trigger a divide-by-zero in __tcp_select_window(), as syzkaller does: divide error: 0000 [#1] SMP KASAN NOPTI CPU: 0 PID: 9667 Comm: syz-executor.0 Not tainted 5.14.0-rc6+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:__tcp_select_window+0x509/0xa60 net/ipv4/tcp_output.c:3016 Code: 44 89 ff e8 c9 29 e9 fd 45 39 e7 0f 8d 20 ff ff ff e8 db 28 e9 fd 44 89 e3 e9 13 ff ff ff e8 ce 28 e9 fd 44 89 e0 44 89 e3 99 <f7> 7c 24 04 29 d3 e9 fc fe ff ff e8 b7 28 e9 fd 44 89 f1 48 89 ea RSP: 0018:ffff888031ccf020 EFLAGS: 00010216 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000040000 RDX: 0000000000000000 RSI: ffff88811532c080 RDI: 0000000000000002 RBP: 0000000000000000 R08: ffffffff835807c2 R09: 0000000000000000 R10: 0000000000000004 R11: ffffed1020b92441 R12: 0000000000000000 R13: 1ffff11006399e08 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fa4c8344700(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f424000 CR3: 000000003e4e2003 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: tcp_select_window net/ipv4/tcp_output.c:264 [inline] __tcp_transmit_skb+0xc00/0x37a0 net/ipv4/tcp_output.c:1351 __tcp_send_ack.part.0+0x3ec/0x760 net/ipv4/tcp_output.c:3972 __tcp_send_ack net/ipv4/tcp_output.c:3978 [inline] tcp_send_ack+0x7d/0xa0 net/ipv4/tcp_output.c:3978 mptcp_pm_nl_addr_send_ack+0x1ab/0x380 net/mptcp/pm_netlink.c:654 mptcp_pm_remove_addr+0x161/0x200 net/mptcp/pm.c:58 mptcp_nl_remove_id_zero_address+0x197/0x460 net/mptcp/pm_netlink.c:1328 mptcp_nl_cmd_del_addr+0x98b/0xd40 net/mptcp/pm_netlink.c:1359 genl_family_rcv_msg_doit.isra.0+0x225/0x340 net/netlink/genetlink.c:731 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x341/0x5b0 net/netlink/genetlink.c:792 netlink_rcv_skb+0x148/0x430 net/netlink/af_netlink.c:2504 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x537/0x750 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x846/0xd80 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0x14e/0x190 net/socket.c:724 ____sys_sendmsg+0x709/0x870 net/socket.c:2403 ___sys_sendmsg+0xff/0x170 net/socket.c:2457 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2486 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae mptcp_pm_nl_addr_send_ack() was attempting to send a TCP ACK on the first subflow in the MPTCP socket's connection list without validating that the subflow was in a suitable connection state. To address this, always validate subflow state when sending extra ACKs on subflows for address advertisement or subflow priority change. Fixes: 84dfe3677a6f ("mptcp: send out dedicated ADD_ADDR packet") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/229 Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Acked-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-01mptcp: fix possible divide by zeroPaolo Abeni1-41/+35
Florian noted that if mptcp_alloc_tx_skb() allocation fails in __mptcp_push_pending(), we can end-up invoking mptcp_push_release()/tcp_push() with a zero mss, causing a divide by 0 error. This change addresses the issue refactoring the skb allocation code checking if skb collapsing will happen for sure and doing the skb allocation only after such check. Skb allocation will now happen only after the call to tcp_send_mss() which correctly initializes mss_now. As side bonuses we now fill the skb tx cache only when needed, and this also clean-up a bit the output path. v1 -> v2: - use lockdep_assert_held_once() - Jakub - fix indentation - Jakub Reported-by: Florian Westphal <fw@strlen.de> Fixes: 724cfd2ee8aa ("mptcp: allocate TX skbs in msk context") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-01mptcp: Fix duplicated argument in protocol.hWan Jiabing1-1/+1
Fix the following coccicheck warning: ./net/mptcp/protocol.h:36:50-73: duplicated argument to & or | The OPTION_MPTCP_MPJ_SYNACK here is duplicate. Here should be OPTION_MPTCP_MPJ_ACK. Fixes: 74c7dfbee3e18 ("mptcp: consolidate in_opt sub-options fields in a bitmask") Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-27mptcp: make the locking tx schema more readablePaolo Abeni1-3/+7
Florian noted the locking schema used by __mptcp_push_pending() is hard to follow, let's add some more descriptive comments and drop an unneeded and confusing check. Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-27mptcp: optimize the input options processingPaolo Abeni1-34/+37
Most MPTCP packets carries a single MPTCP subption: the DSS containing the mapping for the current packet. Check explicitly for the above, so that is such scenario we replace most conditional statements with a single likely() one. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-27mptcp: consolidate in_opt sub-options fields in a bitmaskPaolo Abeni4-73/+63
This makes input options processing more consistent with output ones and will simplify the next patch. Also avoid clearing the suboption field after processing it, since it's not needed. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-27mptcp: better binary layout for mptcp_options_receivedPaolo Abeni2-15/+13
This change reorder the mptcp_options_received fields to shrink the structure a bit and to ensure the most frequently used fields are all in the first cacheline. Sub-opt specific flags are moved out of the suboptions area, and we must now explicitly set them when the relevant suboption is parsed. There is a notable exception: 'csum_reqd' is used by both DSS and MPC suboptions, and keeping such field in the suboptions flag area will simplfy the next patch. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-27mptcp: do not set unconditionally csum_reqd on incoming optPaolo Abeni1-3/+1
Should be set only if the ingress packets present it, otherwise we can confuse csum validation. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25mptcp: add the mibs for MP_FAILGeliang Tang4-0/+6
This patch added the mibs for MP_FAIL: MPTCP_MIB_MPFAILTX and MPTCP_MIB_MPFAILRX. Signed-off-by: Geliang Tang <geliangtang@xiaomi.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25mptcp: send out MP_FAIL when data checksum failsGeliang Tang2-0/+28
When a bad checksum is detected, set the send_mp_fail flag to send out the MP_FAIL option. Add a new function mptcp_has_another_subflow() to check whether there's only a single subflow. When multiple subflows are in use, close the affected subflow with a RST that includes an MP_FAIL option and discard the data with the bad checksum. Set the sk_state of the subsocket to TCP_CLOSE, then the flag MPTCP_WORK_CLOSE_SUBFLOW will be set in subflow_sched_work_if_closed, and the subflow will be closed. When a single subfow is in use, temporarily handled by sending MP_FAIL with a RST too. Signed-off-by: Geliang Tang <geliangtang@xiaomi.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25mptcp: MP_FAIL suboption receivingGeliang Tang3-0/+24
This patch added handling for receiving MP_FAIL suboption. Add a new members mp_fail and fail_seq in struct mptcp_options_received. When MP_FAIL suboption is received, set mp_fail to 1 and save the sequence number to fail_seq. Then invoke mptcp_pm_mp_fail_received to deal with the MP_FAIL suboption. Signed-off-by: Geliang Tang <geliangtang@xiaomi.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25mptcp: MP_FAIL suboption sendingGeliang Tang2-4/+58
This patch added the MP_FAIL suboption sending support. Add a new flag named send_mp_fail in struct mptcp_subflow_context. If this flag is set, send out MP_FAIL suboption. Add a new member fail_seq in struct mptcp_out_options to save the data sequence number to put into the MP_FAIL suboption. An MP_FAIL option could be included in a RST or on the subflow-level ACK. Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Geliang Tang <geliangtang@xiaomi.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25mptcp: optimize out option generationPaolo Abeni2-109/+121
Currently we have several protocol constraints on MPTCP options generation (e.g. MPC and MPJ subopt are mutually exclusive) and some additional ones required by our implementation (e.g. almost all ADD_ADDR variant are mutually exclusive with everything else). We can leverage the above to optimize the out option generation: we check DSS/MPC/MPJ presence in a mutually exclusive way, avoiding many unneeded conditionals in the common cases. Additionally extend the existing constraints on ADD_ADDR opt on all subvariants, so that it becomes fully mutually exclusive with the above and we can skip another conditional statement for the common case. This change is also needed by the next patch. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24mptcp: remove MPTCP_ADD_ADDR_IPV6 and MPTCP_ADD_ADDR_PORTYonglong Li3-21/+3
MPTCP_ADD_ADDR_IPV6 and MPTCP_ADD_ADDR_PORT are not necessary, we can get these info from pm.local or pm.remote. Drop mptcp_pm_should_add_signal_ipv6 and mptcp_pm_should_add_signal_port too. Co-developed-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24mptcp: build ADD_ADDR/echo-ADD_ADDR option according pm.add_signalYonglong Li2-6/+10
According to the MPTCP_ADD_ADDR_SIGNAL or MPTCP_ADD_ADDR_ECHO flag, build the ADD_ADDR/ADD_ADDR_ECHO option. In mptcp_pm_add_addr_signal(), use opts->addr to save the announced ADD_ADDR or ADD_ADDR_ECHO address. Co-developed-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24mptcp: fix ADD_ADDR and RM_ADDR maybe flush addr_signal each otherYonglong Li1-3/+10
ADD_ADDR shares pm.addr_signal with RM_ADDR, so after RM_ADDR/ADD_ADDR has done, we should not clean ADD_ADDR/RM_ADDR's addr_signal. Co-developed-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24mptcp: make MPTCP_ADD_ADDR_SIGNAL and MPTCP_ADD_ADDR_ECHO separateYonglong Li3-8/+18
Use MPTCP_ADD_ADDR_SIGNAL only for the action of sending ADD_ADDR, and use MPTCP_ADD_ADDR_ECHO only for the action of sending ADD_ADDR echo. Use msk->pm.local to save the announced ADD_ADDR address only, and reuse msk->pm.remote to save the announced ADD_ADDR_ECHO address. To prepare for the next patch. Co-developed-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24mptcp: move drop_other_suboptions check under pm lockYonglong Li3-18/+31
This patch moved the drop_other_suboptions check from mptcp_established_options_add_addr() into mptcp_pm_add_addr_signal(), do it under the PM lock to avoid the race between this check and mptcp_pm_add_addr_signal(). For this, added a new parameter for mptcp_pm_add_addr_signal() to get the drop_other_suboptions value. And drop the other suboptions after the option length check if drop_other_suboptions is true. Additionally, always drop the other suboption for TCP pure ack: that makes both the code simpler and the MPTCP behaviour more consistent. Co-developed-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2-39/+15
drivers/ptp/Kconfig: 55c8fca1dae1 ("ptp_pch: Restore dependency on PCI") e5f31552674e ("ethernet: fix PTP_1588_CLOCK dependencies") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-19mptcp: full fully established support after ADD_ADDRMatthieu Baerts1-7/+3
If directly after an MP_CAPABLE 3WHS, the client receives an ADD_ADDR with HMAC from the server, it is enough to switch to a "fully established" mode because it has received more MPTCP options. It was then OK to enable the "fully_established" flag on the MPTCP socket. Still, best to check if the ADD_ADDR looks valid by looking if it contains an HMAC (no 'echo' bit). If an ADD_ADDR echo is received while we are not in "fully established" mode, it is strange and then we should not switch to this mode now. But that is not enough. On one hand, the path-manager has be notified the state has changed. On the other hand, the "fully_established" flag on the subflow socket should be turned on as well not to re-send the MP_CAPABLE 3rd ACK content with the next ACK. Fixes: 84dfe3677a6f ("mptcp: send out dedicated ADD_ADDR packet") Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-19mptcp: fix memory leak on address flushPaolo Abeni1-32/+12
The endpoint cleanup path is prone to a memory leak, as reported by syzkaller: BUG: memory leak unreferenced object 0xffff88810680ea00 (size 64): comm "syz-executor.6", pid 6191, jiffies 4295756280 (age 24.138s) hex dump (first 32 bytes): 58 75 7d 3c 80 88 ff ff 22 01 00 00 00 00 ad de Xu}<...."....... 01 00 02 00 00 00 00 00 ac 1e 00 07 00 00 00 00 ................ backtrace: [<0000000072a9f72a>] kmalloc include/linux/slab.h:591 [inline] [<0000000072a9f72a>] mptcp_nl_cmd_add_addr+0x287/0x9f0 net/mptcp/pm_netlink.c:1170 [<00000000f6e931bf>] genl_family_rcv_msg_doit.isra.0+0x225/0x340 net/netlink/genetlink.c:731 [<00000000f1504a2c>] genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] [<00000000f1504a2c>] genl_rcv_msg+0x341/0x5b0 net/netlink/genetlink.c:792 [<0000000097e76f6a>] netlink_rcv_skb+0x148/0x430 net/netlink/af_netlink.c:2504 [<00000000ceefa2b8>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 [<000000008ff91aec>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] [<000000008ff91aec>] netlink_unicast+0x537/0x750 net/netlink/af_netlink.c:1340 [<0000000041682c35>] netlink_sendmsg+0x846/0xd80 net/netlink/af_netlink.c:1929 [<00000000df3aa8e7>] sock_sendmsg_nosec net/socket.c:704 [inline] [<00000000df3aa8e7>] sock_sendmsg+0x14e/0x190 net/socket.c:724 [<000000002154c54c>] ____sys_sendmsg+0x709/0x870 net/socket.c:2403 [<000000001aab01d7>] ___sys_sendmsg+0xff/0x170 net/socket.c:2457 [<00000000fa3b1446>] __sys_sendmsg+0xe5/0x1b0 net/socket.c:2486 [<00000000db2ee9c7>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<00000000db2ee9c7>] do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80 [<000000005873517d>] entry_SYSCALL_64_after_hwframe+0x44/0xae We should not require an allocation to cleanup stuff. Rework the code a bit so that the additional RCU work is no more needed. Fixes: 1729cf186d8a ("mptcp: create the listening socket for new port") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-18mptcp: local addresses fullmeshGeliang Tang1-10/+63
In mptcp_pm_nl_add_addr_received(), fill a temporary allocate array of all local address corresponding to the fullmesh endpoint. If such array is empty, keep the current behavior. Elsewhere loop on such array and create a subflow for each local address towards the given remote address Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Geliang Tang <geliangtang@xiaomi.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-18mptcp: remote addresses fullmeshGeliang Tang1-4/+55
This patch added and managed a new per endpoint flag, named MPTCP_PM_ADDR_FLAG_FULLMESH. In mptcp_pm_create_subflow_or_signal_addr(), if such flag is set, instead of: remote_address((struct sock_common *)sk, &remote); fill a temporary allocated array of all known remote address. After releaseing the pm lock loop on such array and create a subflow for each remote address from the given local. Note that the we could still use an array even for non 'fullmesh' endpoint: with a single entry corresponding to the primary MPC subflow remote address. Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Geliang Tang <geliangtang@xiaomi.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-18mptcp: drop flags and ifindex argumentsGeliang Tang3-7/+31
This patch added a new helper mptcp_pm_get_flags_and_ifindex_by_id(), and used it in __mptcp_subflow_connect() to get the flags and ifindex values. Then the two arguments flags and ifindex of __mptcp_subflow_connect() can be dropped. Signed-off-by: Geliang Tang <geliangtang@xiaomi.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14mptcp: backup flag from incoming MPJ ack optionPaolo Abeni1-2/+4
the parsed incoming backup flag is not propagated to the subflow itself, the client may end-up using it to send data. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/191 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14mptcp: add mibs for stale subflows processingPaolo Abeni5-0/+8
This allows monitoring exceptional events like active backup scenarios. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14mptcp: faster active backup recoveryPaolo Abeni5-5/+88
The msk can use backup subflows to transmit in-sequence data only if there are no other active subflow. On active backup scenario, the MPTCP connection can do forward progress only due to MPTCP retransmissions - rtx can pick backup subflows. This patch introduces a new flag flow MPTCP subflows: if the underlying TCP connection made no progresses for long time, and there are other less problematic subflows available, the given subflow become stale. Stale subflows are not considered active: if all non backup subflows become stale, the MPTCP scheduler can pick backup subflows for plain transmissions. Stale subflows can return in active state, as soon as any reply from the peer is observed. Active backup scenarios can now leverage the available b/w with no restrinction. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/207 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14mptcp: cleanup sysctl data and helpersPaolo Abeni2-10/+10
Reorder the data in mptcp_pernet to avoid wasting space with no reasons and constify the access helpers. No functional changes intended. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14mptcp: handle pending data on closed subflowPaolo Abeni3-8/+82
The PM can close active subflow, e.g. due to ingress RM_ADDR option. Such subflow could carry data still unacked at the MPTCP-level, both in the write and the rtx_queue, which has never reached the other peer. Currently the mptcp-level retransmission will deliver such data, but at a very low rate (at most 1 DSM for each MPTCP rtx interval). We can speed-up the recovery a lot, moving all the unacked in the tcp write_queue, so that it will be pushed again via other subflows, at the speed allowed by them. Also make available the new helper for later patches. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/207 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14mptcp: less aggressive retransmission strategyPaolo Abeni3-10/+37
The current mptcp re-inject strategy is very aggressive, we have mptcp-level retransmissions even on single subflow connection, if the link in-use is lossy. Let's be a little more conservative: we do retransmit only if at least a subflow has write and rtx queue empty. Additionally use the backup subflows only if the active subflows are stale - no progresses in at least an rtx period and ignore stale subflows for rtx timeout update Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/207 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14mptcp: more accurate timeoutPaolo Abeni1-23/+37
As reported by Maxim, we have a lot of MPTCP-level retransmissions when multilple links with different latencies are in use. This patch refactor the mptcp-level timeout accounting so that the maximum of all the active subflow timeout is used. To avoid traversing the subflow list multiple times, the update is performed inside the packet scheduler. Additionally clean-up a bit timeout handling. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-04mptcp: drop unused rcu member in mptcp_pm_addr_entryGeliang Tang1-1/+0
kfree_rcu() had been removed from pm_netlink.c, so this rcu field in struct mptcp_pm_addr_entry became useless. Let's drop it. Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Link: https://lore.kernel.org/r/20210802231914.54709-1-mathew.j.martineau@linux.intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-07-13net: Use nlmsg_unicast() instead of netlink_unicast()Yajun Deng1-4/+2
It has 'if (err >0 )' statement in nlmsg_unicast(), so use nlmsg_unicast() instead of netlink_unicast(), this looks more concise. v2: remove the change in netfilter. Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-10mptcp: properly account bulk freed memoryPaolo Abeni4-6/+18
After commit 879526030c8b ("mptcp: protect the rx path with the msk socket spinlock") the rmem currently used by a given msk is really sk_rmem_alloc - rmem_released. The safety check in mptcp_data_ready() does not take the above in due account, as a result legit incoming data is kept in subflow receive queue with no reason, delaying or blocking MPTCP-level ack generation. This change addresses the issue introducing a new helper to fetch the rmem memory and using it as needed. Additionally add a MIB counter for the exceptional event described above - the peer is misbehaving. Finally, introduce the required annotation when rmem_released is updated. Fixes: 879526030c8b ("mptcp: protect the rx path with the msk socket spinlock") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/211 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-10mptcp: avoid processing packet if a subflow resetJianguo Wu1-6/+13
If check_fully_established() causes a subflow reset, it should not continue to process the packet in tcp_data_queue(). Add a return value to mptcp_incoming_options(), and return false if a subflow has been reset, else return true. Then drop the packet in tcp_data_queue()/tcp_rcv_state_process() if mptcp_incoming_options() return false. Fixes: d582484726c4 ("mptcp: fix fallback for MP_JOIN subflows") Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-10mptcp: fix syncookie process if mptcp can not_accept new subflowJianguo Wu1-3/+3
Lots of "TCP: tcp_fin: Impossible, sk->sk_state=7" in client side when doing stress testing using wrk and webfsd. There are at least two cases may trigger this warning: 1.mptcp is in syncookie, and server recv MP_JOIN SYN request, in subflow_check_req(), the mptcp_can_accept_new_subflow() return false, so subflow_init_req_cookie_join_save() isn't called, i.e. not store the data present in the MP_JOIN syn request and the random nonce in hash table - join_entries[], but still send synack. When recv 3rd-ack, mptcp_token_join_cookie_init_state() will return false, and 3rd-ack is dropped, then if mptcp conn is closed by client, client will send a DATA_FIN and a MPTCP FIN, the DATA_FIN doesn't have MP_CAPABLE or MP_JOIN, so mptcp_subflow_init_cookie_req() will return 0, and pass the cookie check, MP_JOIN request is fallback to normal TCP. Server will send a TCP FIN if closed, in client side, when process TCP FIN, it will do reset, the code path is: tcp_data_queue()->mptcp_incoming_options() ->check_fully_established()->mptcp_subflow_reset(). mptcp_subflow_reset() will set sock state to TCP_CLOSE, so tcp_fin will hit TCP_CLOSE, and print the warning. 2.mptcp is in syncookie, and server recv 3rd-ack, in mptcp_subflow_init_cookie_req(), mptcp_can_accept_new_subflow() return false, and subflow_req->mp_join is not set to 1, so in subflow_syn_recv_sock() will not reset the MP_JOIN subflow, but fallback to normal TCP, and then the same thing happens when server will send a TCP FIN if closed. For case1, subflow_check_req() return -EPERM, then tcp_conn_request() will drop MP_JOIN SYN. For case2, let subflow_syn_recv_sock() call mptcp_can_accept_new_subflow(), and do fatal fallback, send reset. Fixes: 9466a1ccebbe ("mptcp: enable JOIN requests even if cookies are in use") Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-10mptcp: remove redundant req destruct in subflow_check_req()Jianguo Wu1-5/+0
In subflow_check_req(), if subflow sport is mismatch, will put msk, destroy token, and destruct req, then return -EPERM, which can be done by subflow_req_destructor() via: tcp_conn_request() |--__reqsk_free() |--subflow_req_destructor() So we should remove these redundant code, otherwise will call tcp_v4_reqsk_destructor() twice, and may double free inet_rsk(req)->ireq_opt. Fixes: 5bc56388c74f ("mptcp: add port number check for MP_JOIN") Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-10mptcp: fix warning in __skb_flow_dissect() when do syn cookie for subflow joinJianguo Wu1-1/+15
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 <pabeni@redhat.com> Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-01net: sock: extend SO_TIMESTAMPING for PHC bindingYangbo Lu1-6/+17
Since PTP virtual clock support is added, there can be several PTP virtual clocks based on one PTP physical clock for timestamping. This patch is to extend SO_TIMESTAMPING API to support PHC (PTP Hardware Clock) binding by adding a new flag SOF_TIMESTAMPING_BIND_PHC. When PTP virtual clocks are in use, user space can configure to bind one for timestamping, but PTP physical clock is not supported and not needed to bind. This patch is preparation for timestamp conversion from raw timestamp to a specific PTP virtual clock time in core net. Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-01mptcp: setsockopt: convert to mptcp_setsockopt_sol_socket_timestamping()Yangbo Lu1-17/+40
Split timestamping handling into a new function mptcp_setsockopt_sol_socket_timestamping(). This is preparation for extending SO_TIMESTAMPING for PHC binding, since optval will no longer be integer. Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski4-41/+53
Trivial conflict in net/netfilter/nf_tables_api.c. Duplicate fix in tools/testing/selftests/net/devlink_port_split.py - take the net-next version. skmsg, and L4 bpf - keep the bpf code but remove the flags and err params. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-06-29net: sock: introduce sk_error_reportAlexander Aring1-1/+1
This patch introduces a function wrapper to call the sk_error_report callback. That will prepare to add additional handling whenever sk_error_report is called, for example to trace socket errors. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-28mptcp: fix 'masking a bool' warningMatthieu Baerts1-1/+1
Dan Carpenter reported an issue introduced in commit fde56eea01f9 ("mptcp: refine mptcp_cleanup_rbuf") where a new boolean (ack_pending) is masked with 0x9. This is not the intention to ignore values by using a boolean. This variable should not have a 'bool' type: we should keep the 'u8' to allow this comparison. Fixes: fde56eea01f9 ("mptcp: refine mptcp_cleanup_rbuf") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-23mptcp: refine mptcp_cleanup_rbufPaolo Abeni2-34/+23
The current cleanup rbuf tries a bit too hard to avoid acquiring the subflow socket lock. We may end-up delaying the needed ack, or skip acking a blocked subflow. Address the above extending the conditions used to trigger the cleanup to reflect more closely what TCP does and invoking tcp_cleanup_rbuf() on all the active subflows. Note that we can't replicate the exact tests implemented in tcp_cleanup_rbuf(), as MPTCP lacks some of the required info - e.g. ping-pong mode. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-23mptcp: add deny_join_id0 in mptcp_options_receivedGeliang Tang5-2/+15
This patch added a new flag named deny_join_id0 in struct mptcp_options_received. Set it when MP_CAPABLE with the flag MPTCP_CAP_DENYJOIN_ID0 is received. Also add a new flag remote_deny_join_id0 in struct mptcp_pm_data. When the flag deny_join_id0 is set, set this remote_deny_join_id0 flag. In mptcp_pm_create_subflow_or_signal_addr, if the remote_deny_join_id0 flag is set, and the remote address id is zero, stop this connection. Suggested-by: Florian Westphal <fw@strlen.de> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>