WSL2-Linux-Kernel/net/ipv4
Eric Dumazet 90385f2b65 tcp: fix tcp_mtup_probe_success vs wrong snd_cwnd
commit 1182576529 upstream.

syzbot got a new report [1] finally pointing to a very old bug,
added in initial support for MTU probing.

tcp_mtu_probe() has checks about starting an MTU probe if
tcp_snd_cwnd(tp) >= 11.

But nothing prevents tcp_snd_cwnd(tp) to be reduced later
and before the MTU probe succeeds.

This bug would lead to potential zero-divides.

Debugging added in commit 4057037535 ("tcp: add accessors
to read/set tp->snd_cwnd") has paid off :)

While we are at it, address potential overflows in this code.

[1]
WARNING: CPU: 1 PID: 14132 at include/net/tcp.h:1219 tcp_mtup_probe_success+0x366/0x570 net/ipv4/tcp_input.c:2712
Modules linked in:
CPU: 1 PID: 14132 Comm: syz-executor.2 Not tainted 5.18.0-syzkaller-07857-gbabf0bb978e3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tcp_snd_cwnd_set include/net/tcp.h:1219 [inline]
RIP: 0010:tcp_mtup_probe_success+0x366/0x570 net/ipv4/tcp_input.c:2712
Code: 74 08 48 89 ef e8 da 80 17 f9 48 8b 45 00 65 48 ff 80 80 03 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 aa b0 c5 f8 <0f> 0b e9 16 fe ff ff 48 8b 4c 24 08 80 e1 07 38 c1 0f 8c c7 fc ff
RSP: 0018:ffffc900079e70f8 EFLAGS: 00010287
RAX: ffffffff88c0f7f6 RBX: ffff8880756e7a80 RCX: 0000000000040000
RDX: ffffc9000c6c4000 RSI: 0000000000031f9e RDI: 0000000000031f9f
RBP: 0000000000000000 R08: ffffffff88c0f606 R09: ffffc900079e7520
R10: ffffed101011226d R11: 1ffff1101011226c R12: 1ffff1100eadcf50
R13: ffff8880756e72c0 R14: 1ffff1100eadcf89 R15: dffffc0000000000
FS:  00007f643236e700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1ab3f1e2a0 CR3: 0000000064fe7000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 tcp_clean_rtx_queue+0x223a/0x2da0 net/ipv4/tcp_input.c:3356
 tcp_ack+0x1962/0x3c90 net/ipv4/tcp_input.c:3861
 tcp_rcv_established+0x7c8/0x1ac0 net/ipv4/tcp_input.c:5973
 tcp_v6_do_rcv+0x57b/0x1210 net/ipv6/tcp_ipv6.c:1476
 sk_backlog_rcv include/net/sock.h:1061 [inline]
 __release_sock+0x1d8/0x4c0 net/core/sock.c:2849
 release_sock+0x5d/0x1c0 net/core/sock.c:3404
 sk_stream_wait_memory+0x700/0xdc0 net/core/stream.c:145
 tcp_sendmsg_locked+0x111d/0x3fc0 net/ipv4/tcp.c:1410
 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1448
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 __sys_sendto+0x439/0x5c0 net/socket.c:2119
 __do_sys_sendto net/socket.c:2131 [inline]
 __se_sys_sendto net/socket.c:2127 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2127
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f6431289109
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f643236e168 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f643139c100 RCX: 00007f6431289109
RDX: 00000000d0d0c2ac RSI: 0000000020000080 RDI: 000000000000000a
RBP: 00007f64312e308d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff372533af R14: 00007f643236e300 R15: 0000000000022000

Fixes: 5d424d5a67 ("[TCP]: MTU probing")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14 18:36:28 +02:00
..
bpfilter net: Revert "net: optimize the sockptr_t for unified kernel/user address spaces" 2020-08-10 12:06:44 -07:00
netfilter netfilter: ipt_CLUSTERIP: fix refcount leak in clusterip_tg_check() 2022-01-27 11:03:50 +01:00
Kconfig net: ipv4: remove duplicate "the the" phrase in Kconfig text 2020-08-18 16:02:16 -07:00
Makefile bpf: Clean up sockmap related Kconfigs 2021-02-26 12:28:03 -08:00
af_inet.c gso: do not skip outer ip header in case of ipip and net_failover 2022-03-02 11:47:56 +01:00
ah4.c Networking changes for 5.14. 2021-06-30 15:51:09 -07:00
arp.c ipv4: Invalidate neighbour for broadcast address upon address addition 2022-04-13 20:59:05 +02:00
bpf_tcp_ca.c bpf: Forbid bpf_ktime_get_coarse_ns and bpf_timer_* in tracing progs 2021-11-25 09:49:07 +01:00
cipso_ipv4.c net: remove the unnecessary check in cipso_v4_doi_free 2021-09-03 13:52:29 +01:00
datagram.c inet: stop leaking jiffies on the wire 2019-11-01 14:57:52 -07:00
devinet.c net: return correct error code 2021-12-08 09:04:38 +01:00
esp4.c esp: limit skb_page_frag_refill use to a single page 2022-04-27 14:38:52 +02:00
esp4_offload.c esp: Fix BEET mode inter address family tunneling on GSO 2022-03-16 14:23:36 +01:00
fib_frontend.c ipv4: Invalidate neighbour for broadcast address upon address addition 2022-04-13 20:59:05 +02:00
fib_lookup.h ipv4: fix data races in fib_alias_hw_flags_set 2022-02-23 12:03:10 +01:00
fib_notifier.c net: fib_notifier: propagate extack down to the notifier block callback 2019-10-04 11:10:56 -07:00
fib_rules.c ipv4: convert fib_num_tclassid_users to atomic_t 2021-12-08 09:04:49 +01:00
fib_semantics.c net: ipv4: fix route with nexthop object delete warning 2022-04-13 20:59:16 +02:00
fib_trie.c ipv4: fix data races in fib_alias_hw_flags_set 2022-02-23 12:03:10 +01:00
fou.c fou: remove sparse errors 2021-08-31 12:03:33 +01:00
gre_demux.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
gre_offload.c ip_gre: add csum offload support for gre header 2021-01-29 20:39:14 -08:00
icmp.c icmp: fix icmp_ext_echo_iio parsing in icmp_build_probe 2021-10-14 07:54:47 -07:00
igmp.c net: igmp: respect RCU rules in ip_mc_source() and ip_mc_msfilter() 2022-05-12 12:30:17 +02:00
inet_connection_sock.c inet: use #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING consistently 2021-12-17 10:30:13 +01:00
inet_diag.c inet_diag: fix kernel-infoleak for UDP sockets 2021-12-22 09:32:40 +01:00
inet_fragment.c inet: frags: annotate races around fqdir->dead and fqdir->high_thresh 2022-01-27 11:05:35 +01:00
inet_hashtables.c tcp: use alloc_large_system_hash() to allocate table_perturb 2022-06-14 18:36:19 +02:00
inet_timewait_sock.c net: Use generic ns_common::count 2020-08-19 14:06:36 +02:00
inetpeer.c inetpeer: use div64_ul() and clamp_val() calculate inet_peer_threshold 2021-03-01 13:32:12 -08:00
ip_forward.c ipv4: Revert removal of rt_uses_gateway 2019-09-20 18:23:33 -07:00
ip_fragment.c inet: frags: annotate races around fqdir->dead and fqdir->high_thresh 2022-01-27 11:05:35 +01:00
ip_gre.c ip_gre: test csum_start instead of transport header 2022-06-14 18:36:19 +02:00
ip_input.c net: use indirect call helpers for dst_input 2021-02-03 14:51:39 -08:00
ip_options.c net: clean up codestyle for net/ipv4 2020-08-25 06:28:02 -07:00
ip_output.c net-timestamp: convert sk->sk_tskey to atomic_t 2022-03-02 11:48:01 +01:00
ip_sockglue.c Revert "Revert "ipv4: fix memory leaks in ip_cmsg_send() callers"" 2021-09-14 14:24:31 +01:00
ip_tunnel.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-07-31 09:14:46 -07:00
ip_tunnel_core.c net: ip_tunnel: clean up endianness conversions 2021-01-08 19:25:35 -08:00
ip_vti.c ip_tunnel: use ndo_siocdevprivate 2021-07-27 20:11:44 +01:00
ipcomp.c Networking changes for 5.14. 2021-06-30 15:51:09 -07:00
ipconfig.c net: ipconfig: Don't override command-line hostnames or domains 2021-06-02 13:27:03 -07:00
ipip.c ip_tunnel: use ndo_siocdevprivate 2021-07-27 20:11:44 +01:00
ipmr.c ipmr,ip6mr: acquire RTNL before calling ip[6]mr_free_table() on failure path 2022-02-16 12:56:29 +01:00
ipmr_base.c net: fib_notifier: propagate extack down to the notifier block callback 2019-10-04 11:10:56 -07:00
metrics.c treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
netfilter.c netfilter: Dissect flow after packet mangling 2021-04-18 22:04:16 +02:00
netlink.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
nexthop.c net: nexthop: release IPv6 per-cpu dsts when replacing a nexthop group 2021-12-01 09:04:49 +01:00
ping.c ping: fix address binding wrt vrf 2022-05-18 10:26:57 +02:00
proc.c tcp: switch orphan_count to bare per-cpu counters 2021-11-18 19:16:33 +01:00
protocol.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
raw.c ipv4: raw: lock the socket in raw_bind() 2022-02-01 17:27:14 +01:00
raw_diag.c net: Use nlmsg_unicast() instead of netlink_unicast() 2021-07-13 09:28:29 -07:00
route.c xfrm: fix "disable_policy" flag use when arriving from different devices 2022-05-25 09:57:30 +02:00
syncookies.c tcp: make sure treq->af_specific is initialized 2022-05-09 09:14:37 +02:00
sysctl_net_ipv4.c net: Introduce net.ipv4.tcp_migrate_req. 2021-06-15 18:01:05 +02:00
tcp.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_bbr.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_bic.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_bpf.c bpf, sockmap: Fix double uncharge the mem of sk_msg 2022-04-08 14:23:40 +02:00
tcp_cdg.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_cong.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_cubic.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_dctcp.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_dctcp.h
tcp_diag.c inet_diag: Move the INET_DIAG_REQ_BYTECODE nlattr to cb->data 2020-02-27 18:50:19 -08:00
tcp_fastopen.c tcp: enable data-less, empty-cookie SYN with TFO_SERVER_COOKIE_NOT_REQD 2021-08-16 17:25:49 -07:00
tcp_highspeed.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_htcp.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_hybla.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_illinois.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_input.c tcp: fix tcp_mtup_probe_success vs wrong snd_cwnd 2022-06-14 18:36:28 +02:00
tcp_ipv4.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_lp.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_metrics.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_minisocks.c tcp: md5: incorrect tcp_header_len for incoming connections 2022-05-09 09:14:35 +02:00
tcp_nv.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_offload.c net, gro: Set inner transport header offset in tcp/udp GRO hook 2021-08-02 10:20:56 +01:00
tcp_output.c tcp: tcp_rtx_synack() can be called from process context 2022-06-14 18:36:12 +02:00
tcp_rate.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_recovery.c tcp: more accurately check DSACKs to grow RACK reordering window 2021-07-27 20:07:21 +01:00
tcp_scalable.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_timer.c net: sock: introduce sk_error_report 2021-06-29 11:28:21 -07:00
tcp_ulp.c bpf: sockmap: Only check ULP for TCP sockets 2020-03-09 22:34:58 +01:00
tcp_vegas.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_vegas.h
tcp_veno.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_westwood.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tcp_yeah.c tcp: add accessors to read/set tp->snd_cwnd 2022-06-14 18:36:11 +02:00
tunnel4.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
udp.c net: udp: fix alignment problem in udp4_seq_show() 2022-01-11 15:35:18 +01:00
udp_bpf.c net: Implement ->sock_is_readable() for UDP and AF_UNIX 2021-10-26 12:29:33 -07:00
udp_diag.c net: Use nlmsg_unicast() instead of netlink_unicast() 2021-07-13 09:28:29 -07:00
udp_impl.h net: pass a sockptr_t into ->setsockopt 2020-07-24 15:41:54 -07:00
udp_offload.c fou: remove sparse errors 2021-08-31 12:03:33 +01:00
udp_tunnel_core.c udp_tunnel: reshuffle NETIF_F_RX_UDP_TUNNEL_PORT checks 2021-01-07 12:53:29 -08:00
udp_tunnel_nic.c udp_tunnel: Fix end of loop test in udp_tunnel_nic_unregister() 2022-03-02 11:47:59 +01:00
udp_tunnel_stub.c udp_tunnel: add central NIC RX port offload infrastructure 2020-07-10 13:54:00 -07:00
udplite.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
xfrm4_input.c xfrm: state: remove extract_input indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
xfrm4_output.c xfrm: fix unused variable warning if CONFIG_NETFILTER=n 2020-05-11 15:12:27 +02:00
xfrm4_policy.c net: add bool confirm_neigh parameter for dst_ops.update_pmtu 2019-12-24 22:28:54 -08:00
xfrm4_protocol.c net: xfrm: unexport __init-annotated xfrm4_protocol_init() 2022-06-14 18:36:18 +02:00
xfrm4_state.c xfrm: remove output_finish indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
xfrm4_tunnel.c xfrm: remove description from xfrm_type struct 2021-06-09 09:38:52 +02:00