linux/net/ipv4
Paolo Abeni 4dabcdf581 tcp: fix mptcp DSS corruption due to large pmtu xmit
Syzkaller was able to trigger a DSS corruption:

  TCP: request_sock_subflow_v4: Possible SYN flooding on port [::]:20002. Sending cookies.
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 5227 at net/mptcp/protocol.c:695 __mptcp_move_skbs_from_subflow+0x20a9/0x21f0 net/mptcp/protocol.c:695
  Modules linked in:
  CPU: 0 UID: 0 PID: 5227 Comm: syz-executor350 Not tainted 6.11.0-syzkaller-08829-gaf9c191ac2a0 #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
  RIP: 0010:__mptcp_move_skbs_from_subflow+0x20a9/0x21f0 net/mptcp/protocol.c:695
  Code: 0f b6 dc 31 ff 89 de e8 b5 dd ea f5 89 d8 48 81 c4 50 01 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 98 da ea f5 90 <0f> 0b 90 e9 47 ff ff ff e8 8a da ea f5 90 0f 0b 90 e9 99 e0 ff ff
  RSP: 0018:ffffc90000006db8 EFLAGS: 00010246
  RAX: ffffffff8ba9df18 RBX: 00000000000055f0 RCX: ffff888030023c00
  RDX: 0000000000000100 RSI: 00000000000081e5 RDI: 00000000000055f0
  RBP: 1ffff110062bf1ae R08: ffffffff8ba9cf12 R09: 1ffff110062bf1b8
  R10: dffffc0000000000 R11: ffffed10062bf1b9 R12: 0000000000000000
  R13: dffffc0000000000 R14: 00000000700cec61 R15: 00000000000081e5
  FS:  000055556679c380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000020287000 CR3: 0000000077892000 CR4: 00000000003506f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <IRQ>
   move_skbs_to_msk net/mptcp/protocol.c:811 [inline]
   mptcp_data_ready+0x29c/0xa90 net/mptcp/protocol.c:854
   subflow_data_ready+0x34a/0x920 net/mptcp/subflow.c:1490
   tcp_data_queue+0x20fd/0x76c0 net/ipv4/tcp_input.c:5283
   tcp_rcv_established+0xfba/0x2020 net/ipv4/tcp_input.c:6237
   tcp_v4_do_rcv+0x96d/0xc70 net/ipv4/tcp_ipv4.c:1915
   tcp_v4_rcv+0x2dc0/0x37f0 net/ipv4/tcp_ipv4.c:2350
   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:5662 [inline]
   __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775
   process_backlog+0x662/0x15b0 net/core/dev.c:6107
   __napi_poll+0xcb/0x490 net/core/dev.c:6771
   napi_poll net/core/dev.c:6840 [inline]
   net_rx_action+0x89b/0x1240 net/core/dev.c:6962
   handle_softirqs+0x2c5/0x980 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:919 [inline]
   __dev_queue_xmit+0x1764/0x3e80 net/core/dev.c:4451
   dev_queue_xmit include/linux/netdevice.h:3094 [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:236
   ip_local_out net/ipv4/ip_output.c:130 [inline]
   __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:536
   __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466
   tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline]
   tcp_mtu_probe net/ipv4/tcp_output.c:2547 [inline]
   tcp_write_xmit+0x641d/0x6bf0 net/ipv4/tcp_output.c:2752
   __tcp_push_pending_frames+0x9b/0x360 net/ipv4/tcp_output.c:3015
   tcp_push_pending_frames include/net/tcp.h:2107 [inline]
   tcp_data_snd_check net/ipv4/tcp_input.c:5714 [inline]
   tcp_rcv_established+0x1026/0x2020 net/ipv4/tcp_input.c:6239
   tcp_v4_do_rcv+0x96d/0xc70 net/ipv4/tcp_ipv4.c:1915
   sk_backlog_rcv include/net/sock.h:1113 [inline]
   __release_sock+0x214/0x350 net/core/sock.c:3072
   release_sock+0x61/0x1f0 net/core/sock.c:3626
   mptcp_push_release net/mptcp/protocol.c:1486 [inline]
   __mptcp_push_pending+0x6b5/0x9f0 net/mptcp/protocol.c:1625
   mptcp_sendmsg+0x10bb/0x1b10 net/mptcp/protocol.c:1903
   sock_sendmsg_nosec net/socket.c:730 [inline]
   __sock_sendmsg+0x1a6/0x270 net/socket.c:745
   ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2603
   ___sys_sendmsg net/socket.c:2657 [inline]
   __sys_sendmsg+0x2aa/0x390 net/socket.c:2686
   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: 0033:0x7fb06e9317f9
  Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 b8 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007ffe2cfd4f98 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
  RAX: ffffffffffffffda RBX: 00007fb06e97f468 RCX: 00007fb06e9317f9
  RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000005
  RBP: 00007fb06e97f446 R08: 0000555500000000 R09: 0000555500000000
  R10: 0000555500000000 R11: 0000000000000246 R12: 00007fb06e97f406
  R13: 0000000000000001 R14: 00007ffe2cfd4fe0 R15: 0000000000000003
   </TASK>

Additionally syzkaller provided a nice reproducer. The repro enables
pmtu on the loopback device, leading to tcp_mtu_probe() generating
very large probe packets.

tcp_can_coalesce_send_queue_head() currently does not check for
mptcp-level invariants, and allowed the creation of cross-DSS probes,
leading to the mentioned corruption.

Address the issue teaching tcp_can_coalesce_send_queue_head() about
mptcp using the tcp_skb_can_collapse(), also reducing the code
duplication.

Fixes: 8571248411 ("tcp: coalesce/collapse must respect MPTCP extensions")
Cc: stable@vger.kernel.org
Reported-by: syzbot+d1bff73460e33101f0e7@syzkaller.appspotmail.com
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/513
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-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-v1-2-c6fb8e93e551@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-09 19:43:44 -07:00
..
netfilter netfilter: nf_tables: prevent nf_skb_duplicated corruption 2024-09-27 13:55:46 +02:00
af_inet.c net: gro: initialize network_offset in network layer 2024-05-27 16:46:59 -07:00
ah4.c net: fill in MODULE_DESCRIPTION()s for ipv4 modules 2024-02-09 14:12:02 -08:00
arp.c arp: Convert ioctl(SIOCGARP) to RCU. 2024-05-01 18:37:07 -07:00
bpf_tcp_ca.c bpf: Check unsupported ops from the bpf_struct_ops's cfi_stubs 2024-07-29 12:54:13 -07:00
cipso_ipv4.c move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
datagram.c ipv4: Set the routing scope properly in ip_route_output_ports(). 2024-02-12 17:33:05 -08:00
devinet.c ipv4: delete redundant judgment statements 2024-08-23 14:27:45 +01:00
esp4_offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-07-15 13:19:17 -07:00
esp4.c net: support non paged skb frags 2024-09-11 20:44:31 -07:00
fib_frontend.c ipv4: Unmask upper DSCP bits in fib_compute_spec_dst() 2024-08-22 16:59:57 -07:00
fib_lookup.h
fib_notifier.c
fib_rules.c ipv4: fib_rules: Add DSCP selector support 2024-09-13 21:15:44 -07:00
fib_semantics.c ipv4: delete redundant judgment statements 2024-08-23 14:27:45 +01:00
fib_trie.c ipv4: Centralize TOS matching 2024-08-20 14:57:08 +02:00
fou_bpf.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
fou_core.c fou: fix initialization of grc 2024-09-09 17:21:47 -07:00
fou_nl.c
fou_nl.h
gre_demux.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
gre_offload.c net: gro: rename skb_gro_header_hard() 2024-03-05 13:30:11 +01:00
icmp.c ipv4: icmp: Unmask upper DSCP bits in icmp_reply() 2024-09-09 14:14:53 +01:00
igmp.c ipv4: Set scope explicitly in ip_route_output(). 2024-04-08 13:20:51 +01:00
inet_connection_sock.c slab updates for 6.12 2024-09-18 08:53:53 +02:00
inet_diag.c tcp: remove volatile qualifier on tw_substate 2024-08-28 17:08:16 -07:00
inet_fragment.c net: Rename mono_delivery_time to tstamp_type for scalabilty 2024-05-23 14:14:23 -07:00
inet_hashtables.c inet: constify 'struct net' parameter of various lookup helpers 2024-08-05 16:22:45 -07:00
inet_timewait_sock.c tcp: move inet_twsk_schedule helper out of header 2024-06-10 11:54:18 +01:00
inetpeer.c net: ipv4: Simplify the allocation of slab caches in inet_initpeers 2024-01-31 16:39:42 -08:00
ip_forward.c net: fix IPSTATS_MIB_OUTFORWDATAGRAMS increment after fragment check 2023-10-13 09:58:45 -07:00
ip_fragment.c net: Rename mono_delivery_time to tstamp_type for scalabilty 2024-05-23 14:14:23 -07:00
ip_gre.c ipv4: ip_gre: Fix drops of small packets in ipgre_xmit 2024-10-01 13:04:03 +02:00
ip_input.c net/ipv4: make use of the helper macro LIST_HEAD() 2024-09-06 18:10:21 -07:00
ip_options.c move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
ip_output.c ipv4: Unmask upper DSCP bits in __ip_queue_xmit() 2024-09-04 16:57:11 -07:00
ip_sockglue.c inet: Add getsockopt support for IP_ROUTER_ALERT and IPV6_ROUTER_ALERT 2024-03-06 12:37:06 +00:00
ip_tunnel_core.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
ip_tunnel.c ipv4: ip_tunnel: Unmask upper DSCP bits in ip_tunnel_xmit() 2024-09-09 14:14:53 +01:00
ip_vti.c netdev_features: convert NETIF_F_LLTX to dev->lltx 2024-09-03 11:36:43 +02:00
ipcomp.c
ipconfig.c
ipip.c netdev_features: convert NETIF_F_LLTX to dev->lltx 2024-09-03 11:36:43 +02:00
ipmr_base.c
ipmr.c ipv4: ipmr: Unmask upper DSCP bits in ipmr_queue_xmit() 2024-09-04 16:57:11 -07:00
Kconfig net/tcp: Expand goo.gl link 2024-07-30 18:35:12 -07:00
Makefile bpfilter: remove bpfilter 2024-01-04 10:23:10 -08:00
metrics.c net: remove NULL-pointer net parameter in ip_metrics_convert 2024-06-05 10:06:00 +01:00
netfilter.c ipv4: netfilter: Unmask upper DSCP bits in ip_route_me_harder() 2024-09-09 14:14:53 +01:00
netlink.c
nexthop.c net: nexthop: delete redundant judgment statements 2024-08-23 14:27:45 +01:00
ping.c ping: use sk_skb_reason_drop to free rx packets 2024-06-19 12:44:22 +01:00
proc.c minmax: add a few more MIN_T/MAX_T users 2024-07-28 13:41:14 -07:00
protocol.c
raw_diag.c inet_diag: add module pointer to "struct inet_diag_handler" 2024-01-23 15:13:54 +01:00
raw.c net: raw: use sk_skb_reason_drop to free rx packets 2024-06-19 12:44:22 +01:00
route.c ipv4: Unmask upper DSCP bits when building flow key 2024-08-31 17:44:51 +01:00
syncookies.c tcp: use sk_skb_reason_drop to free rx packets 2024-06-19 12:44:22 +01:00
sysctl_net_ipv4.c icmp: icmp_msgs_per_sec and icmp_msgs_burst sysctls become per netns 2024-08-30 11:14:06 -07:00
tcp_ao.c net/tcp: Disable TCP-AO static key after RCU grace period 2024-08-04 13:21:50 +01:00
tcp_bbr.c tcp: Add new args for cong_control in tcp_congestion_ops 2024-05-02 16:26:56 -07:00
tcp_bic.c
tcp_bpf.c bpf-next-for-netdev 2024-09-12 20:22:44 -07:00
tcp_cdg.c
tcp_cong.c tcp: Replace strncpy() with strscpy() 2024-07-16 07:52:15 -07:00
tcp_cubic.c bpf: Remove CONFIG_X86 and CONFIG_DYNAMIC_FTRACE guard from the tcp-cc kfuncs 2024-03-28 18:31:40 -07:00
tcp_dctcp.c tcp: Fix shift-out-of-bounds in dctcp_update_alpha(). 2024-05-21 13:34:50 +02:00
tcp_dctcp.h
tcp_diag.c inet_diag: add module pointer to "struct inet_diag_handler" 2024-01-23 15:13:54 +01:00
tcp_fastopen.c net: use unrcu_pointer() helper 2024-06-06 11:52:52 +02:00
tcp_highspeed.c
tcp_htcp.c tcp: Use clamp() in htcp_alpha_update() 2024-08-06 12:16:25 -07:00
tcp_hybla.c
tcp_illinois.c
tcp_input.c tcp: fix TFO SYN_RECV to not zero retrans_stamp with retransmits out 2024-10-03 16:18:04 -07:00
tcp_ipv4.c tcp: RX path for devmem TCP 2024-09-11 20:44:32 -07:00
tcp_lp.c tcp: rename tcp_time_stamp() to tcp_time_stamp_ts() 2023-10-23 09:35:01 +01:00
tcp_metrics.c tcp_metrics: use netlink policy for IPv6 addr len validation 2024-08-19 17:42:57 -07:00
tcp_minisocks.c tcp: RX path for devmem TCP 2024-09-11 20:44:32 -07:00
tcp_nv.c
tcp_offload.c net: gso: fix tcp fraglist segmentation after pull from frag_list 2024-10-02 17:21:47 -07:00
tcp_output.c tcp: fix mptcp DSS corruption due to large pmtu xmit 2024-10-09 19:43:44 -07:00
tcp_plb.c
tcp_rate.c
tcp_recovery.c tcp: fix excessive TLP and RACK timeouts from HZ rounding 2023-10-17 17:25:42 -07:00
tcp_scalable.c
tcp_sigpool.c net/tcp_sigpool: Use nested-BH locking for sigpool_scratch. 2024-06-24 16:41:22 -07:00
tcp_timer.c mptcp: fallback to TCP after SYN+MPC drops 2024-09-11 15:57:50 -07:00
tcp_ulp.c
tcp_vegas.c
tcp_vegas.h
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tcp.c tcp: RX path for devmem TCP 2024-09-11 20:44:32 -07:00
tunnel4.c net: fill in MODULE_DESCRIPTION()s for ipv4 modules 2024-02-09 14:12:02 -08:00
udp_bpf.c
udp_diag.c inet_diag: add module pointer to "struct inet_diag_handler" 2024-01-23 15:13:54 +01:00
udp_impl.h
udp_offload.c gso: fix udp gso fraglist segmentation after pull from frag_list 2024-10-02 17:29:31 -07:00
udp_tunnel_core.c ipv4: udp_tunnel: Unmask upper DSCP bits in udp_tunnel_dst_lookup() 2024-09-09 14:14:53 +01:00
udp_tunnel_nic.c udp_tunnel: Use flex array to simplify code 2023-10-03 11:39:34 +02:00
udp_tunnel_stub.c
udp.c ipv4: udp: Unmask upper DSCP bits during early demux 2024-08-22 16:59:58 -07:00
udplite.c udplite: remove UDPLITE_BIT 2023-09-14 16:16:36 +02:00
xfrm4_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-05-09 10:01:01 -07:00
xfrm4_output.c
xfrm4_policy.c net: ipv{6,4}: Remove the now superfluous sentinel elements from ctl_table array 2024-05-03 13:29:42 +01:00
xfrm4_protocol.c
xfrm4_state.c
xfrm4_tunnel.c net: fill in MODULE_DESCRIPTION()s for ipv4 modules 2024-02-09 14:12:02 -08:00