linux/net
Paolo Abeni 4fd19a3070 mptcp: fix inconsistent state on fastopen race
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: 1e777f39b4 ("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>
2023-12-17 20:54:22 +00:00
..
6lowpan
9p 9p/net: fix possible memory leak in p9_check_errors() 2023-10-27 12:44:13 +09:00
802 net: fill in MODULE_DESCRIPTION()s under net/802* 2023-10-28 11:29:28 +01:00
8021q net: fill in MODULE_DESCRIPTION()s under net/802* 2023-10-28 11:29:28 +01:00
appletalk appletalk: Fix Use-After-Free in atalk_ioctl 2023-12-14 12:02:45 +01:00
atm atm: Fix Use-After-Free in do_vcc_ioctl 2023-12-12 13:14:08 +01:00
ax25 net: implement lockless SO_PRIORITY 2023-10-01 19:09:54 +01:00
batman-adv Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-08-24 10:51:39 -07:00
bluetooth This update includes the following changes: 2023-11-02 16:15:30 -10:00
bpf bpf: Add __bpf_kfunc_{start,end}_defs macros 2023-11-01 22:33:53 -07:00
bpfilter
bridge netfilter: nf_conntrack_bridge: initialize err to 0 2023-11-14 16:16:21 +01:00
caif sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) 2023-06-24 15:50:13 -07:00
can Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-10-12 17:07:34 -07:00
ceph This update includes the following changes: 2023-11-02 16:15:30 -10:00
core net: Return error from sk_stream_wait_connect() if sk_wait_event() fails 2023-12-15 10:48:51 +00:00
dcb net: dcb: choose correct policy to parse DCB_ATTR_BCN 2023-08-01 21:07:46 -07:00
dccp dccp/tcp: Call security_inet_conn_request() after setting IPv6 addresses. 2023-11-02 12:56:03 +01:00
devlink netlink: specs: devlink: add forgotten port function caps enum values 2023-11-01 22:13:43 -07:00
dns_resolver
dsa net: dsa: Rename IFLA_DSA_MASTER to IFLA_DSA_CONDUIT 2023-10-24 13:08:14 -07:00
ethernet
ethtool ethtool: don't propagate EOPNOTSUPP from dumps 2023-11-29 08:43:27 -08:00
handshake Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-10-26 13:46:28 -07:00
hsr hsr: Prevent use after free in prp_create_tagged_frame() 2023-11-01 22:26:04 -07:00
ieee802154 sysctl-6.6-rc1 2023-08-29 17:39:15 -07:00
ife net: sched: ife: fix potential use-after-free 2023-12-15 10:50:18 +00:00
ipv4 Revert "tcp: disable tcp_autocorking for socket when TCP_NODELAY flag is set" 2023-12-13 10:58:54 -08:00
ipv6 net: ipv6: support reporting otherwise unknown prefix flags in RTM_NEWPREFIX 2023-12-08 10:40:51 +00:00
iucv s390: use control register bit defines 2023-09-19 13:26:57 +02:00
kcm net: kcm: fill in MODULE_DESCRIPTION() 2023-11-08 18:17:44 -08:00
key Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-08-18 12:44:56 -07:00
l2tp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-10-05 13:16:47 -07:00
l3mdev
lapb
llc llc: verify mac len before reading mac header 2023-11-01 22:21:32 -07:00
mac80211 wifi: mac80211: mesh_plink: fix matches_local logic 2023-12-12 10:14:57 +01:00
mac802154 Core WPAN changes: 2023-06-24 15:41:46 -07:00
mctp mctp: perform route lookups under a RCU read-side lock 2023-10-10 19:43:22 -07:00
mpls networking: Update to register_net_sysctl_sz 2023-08-15 15:26:18 -07:00
mptcp mptcp: fix inconsistent state on fastopen race 2023-12-17 20:54:22 +00:00
ncsi Revert ncsi: Propagate carrier gain/loss events to the NCSI controller 2023-11-15 09:59:44 +00:00
netfilter netfilter: xt_owner: Fix for unsafe access of sk->sk_socket 2023-12-06 17:52:15 +01:00
netlabel netlabel: Remove unused declaration netlbl_cipsov4_doi_free() 2023-08-02 12:28:22 -07:00
netlink drop_monitor: Require 'CAP_SYS_ADMIN' when joining "events" group 2023-12-07 09:54:02 -08:00
netrom net: implement lockless SO_PRIORITY 2023-10-01 19:09:54 +01:00
nfc nfc: nci: fix possible NULL pointer dereference in send_acknowledge() 2023-10-16 17:34:53 -07:00
nsh
openvswitch net/sched: act_ct: Always fill offloading tuple iifidx 2023-11-08 17:47:08 -08:00
packet packet: Move reference count in packet_sock to atomic_long_t 2023-12-04 14:45:04 -08:00
phonet sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) 2023-06-24 15:50:13 -07:00
psample psample: Require 'CAP_NET_ADMIN' when joining "packets" group 2023-12-07 09:54:02 -08:00
qrtr net: qrtr: Handle IPCR control port format of older targets 2023-07-17 09:02:30 +01:00
rds net: prevent address rewrite in kernel_bind() 2023-10-01 19:31:29 +01:00
rfkill net: rfkill: gpio: set GPIO direction 2023-12-12 10:14:57 +01:00
rose net/rose: fix races in rose_kill_by_device() 2023-12-15 11:59:53 +00:00
rxrpc rxrpc: Defer the response to a PING ACK until we've parsed it 2023-11-17 02:50:33 +00:00
sched net/sched: act_ct: Take per-cb reference to tcf_ct_flow_table 2023-12-11 09:59:58 +00:00
sctp net: fill in MODULE_DESCRIPTION()s for SOCK_DIAG modules 2023-11-19 20:09:13 +00:00
smc net/smc: fix missing byte order conversion in CLC handshake 2023-12-07 10:10:56 -08:00
strparser
sunrpc NFS client updates for Linux 6.7 2023-11-08 13:39:16 -08:00
switchdev net: switchdev: Add a helper to replay objects on a bridge port 2023-07-21 08:54:03 +01:00
tipc net: fill in MODULE_DESCRIPTION()s for SOCK_DIAG modules 2023-11-19 20:09:13 +00:00
tls net: tls, update curr on splice as well 2023-12-07 09:52:28 -08:00
unix bpf, sockmap: af_unix stream sockets need to hold ref for pair sock 2023-11-30 00:25:16 +01:00
vmw_vsock vsock/virtio: Fix unsigned integer wrap around in virtio_transport_has_space() 2023-12-13 17:59:08 -08:00
wireless wifi: cfg80211: fix certs build to not depend on file order 2023-12-14 09:11:51 +01:00
x25 net: implement lockless SO_PRIORITY 2023-10-01 19:09:54 +01:00
xdp xsk: Skip polling event check for unbound socket 2023-12-05 13:43:43 +01:00
xfrm Including fixes from netfilter and bpf. 2023-11-09 17:09:35 -08:00
compat.c
devres.c
Kconfig net: add skb_segment kunit test 2023-10-11 10:39:01 +01:00
Kconfig.debug
Makefile
socket.c bpf: Add __bpf_hook_{start,end} macros 2023-11-01 22:33:53 -07:00
sysctl_net.c sysctl: Add size to register_net_sysctl function 2023-08-15 15:26:17 -07:00