linux/net/ipv4
Kuniyuki Iwashima 04d9d1fc42 tcp: Fix refcnt handling in __inet_hash_connect().
syzbot reported a warning in sk_nulls_del_node_init_rcu().

The commit 66b60b0c8c ("dccp/tcp: Unhash sk from ehash for tb2 alloc
failure after check_estalblished().") tried to fix an issue that an
unconnected socket occupies an ehash entry when bhash2 allocation fails.

In such a case, we need to revert changes done by check_established(),
which does not hold refcnt when inserting socket into ehash.

So, to revert the change, we need to __sk_nulls_add_node_rcu() instead
of sk_nulls_add_node_rcu().

Otherwise, sock_put() will cause refcnt underflow and leak the socket.

[0]:
WARNING: CPU: 0 PID: 23948 at include/net/sock.h:799 sk_nulls_del_node_init_rcu+0x166/0x1a0 include/net/sock.h:799
Modules linked in:
CPU: 0 PID: 23948 Comm: syz-executor.2 Not tainted 6.8.0-rc6-syzkaller-00159-gc055fc00c07b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:sk_nulls_del_node_init_rcu+0x166/0x1a0 include/net/sock.h:799
Code: e8 7f 71 c6 f7 83 fb 02 7c 25 e8 35 6d c6 f7 4d 85 f6 0f 95 c0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 1b 6d c6 f7 90 <0f> 0b 90 eb b2 e8 10 6d c6 f7 4c 89 e7 be 04 00 00 00 e8 63 e7 d2
RSP: 0018:ffffc900032d7848 EFLAGS: 00010246
RAX: ffffffff89cd0035 RBX: 0000000000000001 RCX: 0000000000040000
RDX: ffffc90004de1000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: 1ffff1100439ac26 R08: ffffffff89ccffe3 R09: 1ffff1100439ac28
R10: dffffc0000000000 R11: ffffed100439ac29 R12: ffff888021cd6140
R13: dffffc0000000000 R14: ffff88802a9bf5c0 R15: ffff888021cd6130
FS:  00007f3b823f16c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3b823f0ff8 CR3: 000000004674a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __inet_hash_connect+0x140f/0x20b0 net/ipv4/inet_hashtables.c:1139
 dccp_v6_connect+0xcb9/0x1480 net/dccp/ipv6.c:956
 __inet_stream_connect+0x262/0xf30 net/ipv4/af_inet.c:678
 inet_stream_connect+0x65/0xa0 net/ipv4/af_inet.c:749
 __sys_connect_file net/socket.c:2048 [inline]
 __sys_connect+0x2df/0x310 net/socket.c:2065
 __do_sys_connect net/socket.c:2075 [inline]
 __se_sys_connect net/socket.c:2072 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2072
 do_syscall_64+0xf9/0x240
 entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f3b8167dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3b823f10c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f3b817abf80 RCX: 00007f3b8167dda9
RDX: 000000000000001c RSI: 0000000020000040 RDI: 0000000000000003
RBP: 00007f3b823f1120 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 000000000000000b R14: 00007f3b817abf80 R15: 00007ffd3beb57b8
 </TASK>

Reported-by: syzbot+12c506c1aae251e70449@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=12c506c1aae251e70449
Fixes: 66b60b0c8c ("dccp/tcp: Unhash sk from ehash for tb2 alloc failure after check_estalblished().")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240308201623.65448-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-03-14 10:57:02 +01:00
..
netfilter netfilter: xtables: fix up kconfig dependencies 2024-02-21 11:57:11 +01:00
af_inet.c net: introduce include/net/rps.h 2024-03-07 21:12:43 -08:00
ah4.c net: fill in MODULE_DESCRIPTION()s for ipv4 modules 2024-02-09 14:12:02 -08:00
arp.c arp: Prevent overflow in arp_req_get(). 2024-02-20 10:50:19 +01:00
bpf_tcp_ca.c bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
cipso_ipv4.c netlabel: remove impossible return value in netlbl_bitmap_walk 2024-02-28 19:37:34 -08:00
datagram.c ipv4: Set the routing scope properly in ip_route_output_ports(). 2024-02-12 17:33:05 -08:00
devinet.c netlink: let core handle error cases in dump operations 2024-03-07 20:48:22 -08:00
esp4_offload.c xfrm: Support GRO for IPv4 ESP in UDP encapsulation 2023-10-06 07:30:40 +02:00
esp4.c net: fill in MODULE_DESCRIPTION()s for ipv4 modules 2024-02-09 14:12:02 -08:00
fib_frontend.c netlink: let core handle error cases in dump operations 2024-03-07 20:48:22 -08:00
fib_lookup.h
fib_notifier.c
fib_rules.c fib: remove unnecessary input parameters in fib_default_rule_add 2024-01-03 16:42:48 -08:00
fib_semantics.c ipv4: fib: annotate races around nh->nh_saddr_genid and nh->nh_saddr 2023-10-18 18:11:31 -07:00
fib_trie.c inet: switch inet_dump_fib() to RCU protection 2024-02-26 11:46:13 +00:00
fou_bpf.c bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
fou_core.c net: gro: rename skb_gro_header_hard() 2024-03-05 13:30:11 +01:00
fou_nl.c
fou_nl.h
gre_demux.c
gre_offload.c net: gro: rename skb_gro_header_hard() 2024-03-05 13:30:11 +01:00
icmp.c xfrm: pass struct net to xfrm_decode_session wrappers 2023-10-06 08:31:53 +02:00
igmp.c inet: annotate devconf data-races 2024-02-28 19:36:39 -08:00
inet_connection_sock.c sock: Use unsafe_memcpy() for sock_copy() 2024-03-05 18:35:12 -08:00
inet_diag.c inet_diag: skip over empty buckets 2024-01-23 15:13:55 +01:00
inet_fragment.c
inet_hashtables.c tcp: Fix refcnt handling in __inet_hash_connect(). 2024-03-14 10:57:02 +01:00
inet_timewait_sock.c tcp: Fix NEW_SYN_RECV handling in inet_twsk_purge() 2024-03-12 18:56:15 -07:00
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 networking: Update to register_net_sysctl_sz 2023-08-15 15:26:18 -07:00
ip_gre.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-02-15 16:20:04 -08:00
ip_input.c ipv4: ignore dst hint for multipath routes 2023-09-01 08:11:51 +01:00
ip_options.c
ip_output.c net: Re-use and set mono_delivery_time bit for userspace tstamp packets 2024-03-05 13:41:16 +01:00
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 tunnels: fix out of bounds access when building IPv6 PMTU error 2024-02-03 12:43:19 +00:00
ip_tunnel.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-03-11 20:38:36 -07:00
ip_vti.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-02-15 16:20:04 -08:00
ipcomp.c
ipconfig.c
ipip.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-02-15 16:20:04 -08:00
ipmr_base.c
ipmr.c ipmr: fix incorrect parameter validation in the ip_mroute_getsockopt() function 2024-03-11 09:53:22 +00:00
Kconfig net/tcp: Add TCP-AO config and structures 2023-10-27 10:35:44 +01:00
Makefile bpfilter: remove bpfilter 2024-01-04 10:23:10 -08:00
metrics.c
netfilter.c xfrm: pass struct net to xfrm_decode_session wrappers 2023-10-06 08:31:53 +02:00
netlink.c
nexthop.c nexthop: Fix splat with CONFIG_DEBUG_PREEMPT=y 2024-03-11 20:35:20 -07:00
ping.c bpf-next-for-netdev 2023-10-16 21:05:33 -07:00
proc.c inet: annotate devconf data-races 2024-02-28 19:36:39 -08:00
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 ipv4: raw: check sk->sk_rcvbuf earlier 2024-03-08 11:39:44 -08:00
route.c inet: annotate devconf data-races 2024-02-28 19:36:39 -08:00
syncookies.c tcp: use drop reasons in cookie check for ipv4 2024-02-28 10:39:21 +00:00
sysctl_net_ipv4.c Use READ/WRITE_ONCE() for IP local_port_range. 2023-12-08 10:44:42 -08:00
tcp_ao.c net: tcp: Remove redundant initialization of variable len 2024-02-20 11:40:15 +01:00
tcp_bbr.c bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
tcp_bic.c
tcp_bpf.c tcp_bpf: properly release resources on error paths 2023-10-18 18:09:31 -07:00
tcp_cdg.c
tcp_cong.c bpf, net: validate struct_ops when updating value. 2024-03-04 10:03:57 -08:00
tcp_cubic.c bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
tcp_dctcp.c bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
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 inet: move inet->defer_connect to inet->inet_flags 2023-08-16 11:09:18 +01:00
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c
tcp_illinois.c
tcp_input.c tcp: add dropreasons in tcp_rcv_state_process() 2024-02-28 10:39:22 +00:00
tcp_ipv4.c tcp: make dropreason in tcp_child_process() work 2024-02-28 10:39:22 +00:00
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: optimize tcp_metrics_flush_all() 2023-10-03 10:05:22 +02:00
tcp_minisocks.c rds: tcp: Fix use-after-free of net in reqsk_timer_handler(). 2024-03-12 18:56:16 -07:00
tcp_nv.c
tcp_offload.c net: move tcpv4_offload and tcpv6_offload to net_hotdata 2024-03-07 21:12:42 -08:00
tcp_output.c net: Remove acked SYN flag from packet in the transmit queue correctly 2023-12-12 15:56:02 -08:00
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 kref_get_unless_zero() 2024-01-01 14:42:05 +00:00
tcp_timer.c tcp: use tp->total_rto to track number of linear timeouts in SYN_SENT state 2023-11-16 23:35:12 +00:00
tcp_ulp.c
tcp_vegas.c
tcp_vegas.h
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tcp.c tcp: annotate a data-race around sysctl_tcp_wmem[0] 2024-03-11 10:37:40 +00:00
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 udp: move udpv4_offload and udpv6_offload to net_hotdata 2024-03-07 21:12:43 -08:00
udp_tunnel_core.c net: fill in MODULE_DESCRIPTION()s for ipv4 modules 2024-02-09 14:12:02 -08:00
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 udp: no longer touch sk->sk_refcnt in early demux 2024-03-11 09:56:03 +00:00
udplite.c udplite: remove UDPLITE_BIT 2023-09-14 16:16:36 +02:00
xfrm4_input.c net: adopt skb_network_offset() and similar helpers 2024-03-04 08:47:06 +00:00
xfrm4_output.c
xfrm4_policy.c sysctl-6.6-rc1 2023-08-29 17:39:15 -07:00
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