android_kernel_samsung_sm8650/net/ipv4
Eric Dumazet 1182576529 tcp: fix tcp_mtup_probe_success vs wrong snd_cwnd
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>
2022-05-28 12:42:08 +01:00
..
bpfilter net: Revert "net: optimize the sockptr_t for unified kernel/user address spaces" 2020-08-10 12:06:44 -07:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next 2022-05-16 10:10:37 +01:00
af_inet.c ipv4: Avoid using RTO_ONLINK with ip_route_connect(). 2022-04-22 13:06:03 +01:00
ah4.c Networking changes for 5.14. 2021-06-30 15:51:09 -07:00
arp.c arp: fix unused variable warnning when CONFIG_PROC_FS=n 2022-04-25 11:50:18 +01:00
bpf_tcp_ca.c bpf: reject program if a __user tagged memory accessed in kernel way 2022-01-27 12:03:46 -08:00
cipso_ipv4.c NET: IPV4: fix error "do not initialise globals to 0" 2021-09-19 12:43:56 +01:00
datagram.c ipv4: Avoid using RTO_ONLINK with ip_route_connect(). 2022-04-22 13:06:03 +01:00
devinet.c Networking changes for 5.19. 2022-05-25 12:22:58 -07:00
esp4_offload.c net: Fix esp GSO on inter address family tunnels. 2022-03-07 13:14:04 +01:00
esp4.c xfrm: free not used XFRM_ESP_NO_TRAILER flag 2022-05-06 08:24:20 +02:00
fib_frontend.c ipv4: remove unnecessary type castings 2022-04-30 15:12:58 +01:00
fib_lookup.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-17 11:44:20 -08:00
fib_notifier.c net: ipv4: remove superfluous header files from fib_notifier.c 2021-09-28 17:32:56 -07:00
fib_rules.c ipv4: remove unnecessary type castings 2022-04-30 15:12:58 +01:00
fib_semantics.c ipv4: Use dscp_t in struct fib_rt_info 2022-04-11 17:37:50 -07:00
fib_trie.c ipv4: remove unnecessary type castings 2022-04-30 15:12:58 +01:00
fou.c fou: Remove XRFM from NET_FOU Kconfig 2022-04-12 14:56:33 -07:00
gre_demux.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
gre_offload.c gro: remove rcu_read_lock/rcu_read_unlock from gro_complete handlers 2021-11-24 17:21:42 -08:00
icmp.c ipv4: remove unnecessary type castings 2022-04-30 15:12:58 +01:00
igmp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-05-05 13:03:18 -07:00
inet_connection_sock.c net: Add a second bind table hashed by port and address 2022-05-20 18:16:24 -07:00
inet_diag.c net: inet: Retire port only listening_hash 2022-05-12 16:52:18 -07:00
inet_fragment.c ipv4: remove unnecessary type castings 2022-04-30 15:12:58 +01:00
inet_hashtables.c net: Add a second bind table hashed by port and address 2022-05-20 18:16:24 -07:00
inet_timewait_sock.c Revert "tcp/dccp: get rid of inet_twsk_purge()" 2022-05-13 12:24:12 +01:00
inetpeer.c inetpeer: use div64_ul() and clamp_val() calculate inet_peer_threshold 2021-03-01 13:32:12 -08:00
ip_forward.c net: ip: add skb drop reasons to ip forwarding 2022-04-13 13:09:57 +01:00
ip_fragment.c net: ip: Handle delivery_time in ip defrag 2022-03-03 14:38:48 +00:00
ip_gre.c ip_gre: Make GRE and GRETAP devices always NETIF_F_LLTX 2022-05-02 10:30:33 +02:00
ip_input.c net-core: rx_otherhost_dropped to core_stats 2022-04-07 20:32:49 -07:00
ip_options.c ipv4: drop fragmentation code from ip_options_build() 2022-01-29 17:53:07 +00:00
ip_output.c net: Set skb->mono_delivery_time and clear it after sch_handle_ingress() 2022-03-03 14:38:48 +00:00
ip_sockglue.c ipv4: Exposing __ip_sock_set_tos() in ip.h 2021-11-20 14:11:00 +00:00
ip_tunnel_core.c net: ip_tunnel: clean up endianness conversions 2021-01-08 19:25:35 -08:00
ip_tunnel.c net: Handle l3mdev in ip_tunnel_init_flow 2022-04-15 14:27:30 -07:00
ip_vti.c ip: use dev_addr_set() in tunnels 2021-10-13 09:41:37 -07:00
ipcomp.c Networking changes for 5.14. 2021-06-30 15:51:09 -07:00
ipconfig.c net: ipconfig: Release the rtnl_lock while waiting for carrier 2021-10-28 14:36:41 +01:00
ipip.c ip: use dev_addr_set() in tunnels 2021-10-13 09:41:37 -07:00
ipmr_base.c net: fib_notifier: propagate extack down to the notifier block callback 2019-10-04 11:10:56 -07:00
ipmr.c ipv4: remove unnecessary type castings 2022-04-30 15:12:58 +01:00
Kconfig fou: Remove XRFM from NET_FOU Kconfig 2022-04-12 14:56:33 -07:00
Makefile bpf: Clean up sockmap related Kconfigs 2021-02-26 12:28:03 -08:00
metrics.c treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
netfilter.c netfilter: Use l3mdev flow key when re-routing mangled packets 2022-05-16 13:03:29 +02:00
netlink.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
nexthop.c nexthop: change nexthop_net_exit() to nexthop_net_exit_batch() 2022-02-08 20:41:33 -08:00
ping.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-05-12 16:15:30 -07:00
proc.c tcp: allocate tcp_death_row outside of struct netns_ipv4 2022-01-26 19:00:31 -08:00
protocol.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
raw_diag.c net: Use nlmsg_unicast() instead of netlink_unicast() 2021-07-13 09:28:29 -07:00
raw.c net: SO_RCVMARK socket option for SO_MARK with recvmsg() 2022-04-28 13:08:15 -07:00
route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-05-19 11:23:59 -07:00
syncookies.c tcp: make sure treq->af_specific is initialized 2022-04-25 12:10:11 +01:00
sysctl_net_ipv4.c net: sysctl: introduce sysctl SYSCTL_THREE 2022-05-03 10:15:06 +02:00
tcp_bbr.c net: allow gso_max_size to exceed 65536 2022-05-16 10:18:55 +01:00
tcp_bic.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_bpf.c net: remove noblock parameter from recvmsg() entities 2022-04-12 15:00:25 +02:00
tcp_cdg.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_cong.c tcp: Add tracepoint for tcp_set_ca_state 2022-04-07 20:33:15 -07:00
tcp_cubic.c tcp_cubic: make hystart_ack_delay() aware of BIG TCP 2022-05-16 10:18:56 +01:00
tcp_dctcp.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_dctcp.h tcp: refactor DCTCP ECN ACK handling 2018-10-10 22:26:00 -07:00
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 net/ipv4/tcp_fastopen.c: remove superfluous header files from tcp_fastopen.c 2021-09-20 13:09:06 +01:00
tcp_highspeed.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_htcp.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_hybla.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_illinois.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_input.c tcp: fix tcp_mtup_probe_success vs wrong snd_cwnd 2022-05-28 12:42:08 +01:00
tcp_ipv4.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-05-19 11:23:59 -07:00
tcp_lp.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_metrics.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_minisocks.c tcp: md5: incorrect tcp_header_len for incoming connections 2022-04-22 15:05:59 -07:00
tcp_nv.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_offload.c net: move gro definitions to include/net/gro.h 2021-11-16 13:16:54 +00:00
tcp_output.c net: allow gso_max_size to exceed 65536 2022-05-16 10:18:55 +01:00
tcp_rate.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-04-28 13:02:01 -07:00
tcp_recovery.c tcp: use tcp_skb_sent_after() instead in RACK 2022-04-30 13:56:46 +01:00
tcp_scalable.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
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 2022-04-06 12:05:41 -07:00
tcp_vegas.h
tcp_veno.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_westwood.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_yeah.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp.c net: Add a second bind table hashed by port and address 2022-05-20 18:16:24 -07:00
tunnel4.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
udp_bpf.c net: remove noblock parameter from recvmsg() entities 2022-04-12 15:00:25 +02:00
udp_diag.c net: Use nlmsg_unicast() instead of netlink_unicast() 2021-07-13 09:28:29 -07:00
udp_impl.h net: remove noblock parameter from recvmsg() entities 2022-04-12 15:00:25 +02:00
udp_offload.c gro: remove rcu_read_lock/rcu_read_unlock from gro_complete handlers 2021-11-24 17:21:42 -08:00
udp_tunnel_core.c net/ipv4/udp_tunnel_core.c: remove superfluous header files from udp_tunnel_core.c 2021-09-21 10:17:20 +01:00
udp_tunnel_nic.c udp_tunnel: Fix end of loop test in udp_tunnel_nic_unregister() 2022-02-23 12:35:00 +00:00
udp_tunnel_stub.c udp_tunnel: add central NIC RX port offload infrastructure 2020-07-10 13:54:00 -07:00
udp.c inet: rename INET_MATCH() 2022-05-16 10:31:06 +01:00
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 l3mdev index to flow struct and avoid oif reset for port devices 2022-03-15 20:20:02 -07:00
xfrm4_protocol.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
xfrm4_state.c xfrm: remove output_finish indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
xfrm4_tunnel.c net/ipv4/xfrm4_tunnel.c: remove superfluous header files from xfrm4_tunnel.c 2021-09-23 10:10:00 +02:00