linux-stable/net/ipv4
Kuniyuki Iwashima 13ed7cdf07 tcp: Use refcount_inc_not_zero() in tcp_twsk_unique().
[ Upstream commit f2db7230f7 ]

Anderson Nascimento reported a use-after-free splat in tcp_twsk_unique()
with nice analysis.

Since commit ec94c2696f ("tcp/dccp: avoid one atomic operation for
timewait hashdance"), inet_twsk_hashdance() sets TIME-WAIT socket's
sk_refcnt after putting it into ehash and releasing the bucket lock.

Thus, there is a small race window where other threads could try to
reuse the port during connect() and call sock_hold() in tcp_twsk_unique()
for the TIME-WAIT socket with zero refcnt.

If that happens, the refcnt taken by tcp_twsk_unique() is overwritten
and sock_put() will cause underflow, triggering a real use-after-free
somewhere else.

To avoid the use-after-free, we need to use refcount_inc_not_zero() in
tcp_twsk_unique() and give up on reusing the port if it returns false.

[0]:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 1039313 at lib/refcount.c:25 refcount_warn_saturate+0xe5/0x110
CPU: 0 PID: 1039313 Comm: trigger Not tainted 6.8.6-200.fc39.x86_64 #1
Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.21805430.B64.2305221830 05/22/2023
RIP: 0010:refcount_warn_saturate+0xe5/0x110
Code: 42 8e ff 0f 0b c3 cc cc cc cc 80 3d aa 13 ea 01 00 0f 85 5e ff ff ff 48 c7 c7 f8 8e b7 82 c6 05 96 13 ea 01 01 e8 7b 42 8e ff <0f> 0b c3 cc cc cc cc 48 c7 c7 50 8f b7 82 c6 05 7a 13 ea 01 01 e8
RSP: 0018:ffffc90006b43b60 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff888009bb3ef0 RCX: 0000000000000027
RDX: ffff88807be218c8 RSI: 0000000000000001 RDI: ffff88807be218c0
RBP: 0000000000069d70 R08: 0000000000000000 R09: ffffc90006b439f0
R10: ffffc90006b439e8 R11: 0000000000000003 R12: ffff8880029ede84
R13: 0000000000004e20 R14: ffffffff84356dc0 R15: ffff888009bb3ef0
FS:  00007f62c10926c0(0000) GS:ffff88807be00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020ccb000 CR3: 000000004628c005 CR4: 0000000000f70ef0
PKRU: 55555554
Call Trace:
 <TASK>
 ? refcount_warn_saturate+0xe5/0x110
 ? __warn+0x81/0x130
 ? refcount_warn_saturate+0xe5/0x110
 ? report_bug+0x171/0x1a0
 ? refcount_warn_saturate+0xe5/0x110
 ? handle_bug+0x3c/0x80
 ? exc_invalid_op+0x17/0x70
 ? asm_exc_invalid_op+0x1a/0x20
 ? refcount_warn_saturate+0xe5/0x110
 tcp_twsk_unique+0x186/0x190
 __inet_check_established+0x176/0x2d0
 __inet_hash_connect+0x74/0x7d0
 ? __pfx___inet_check_established+0x10/0x10
 tcp_v4_connect+0x278/0x530
 __inet_stream_connect+0x10f/0x3d0
 inet_stream_connect+0x3a/0x60
 __sys_connect+0xa8/0xd0
 __x64_sys_connect+0x18/0x20
 do_syscall_64+0x83/0x170
 entry_SYSCALL_64_after_hwframe+0x78/0x80
RIP: 0033:0x7f62c11a885d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 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 8b 0d a3 45 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007f62c1091e58 EFLAGS: 00000296 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000020ccb004 RCX: 00007f62c11a885d
RDX: 0000000000000010 RSI: 0000000020ccb000 RDI: 0000000000000003
RBP: 00007f62c1091e90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 00007f62c10926c0
R13: ffffffffffffff88 R14: 0000000000000000 R15: 00007ffe237885b0
 </TASK>

Fixes: ec94c2696f ("tcp/dccp: avoid one atomic operation for timewait hashdance")
Reported-by: Anderson Nascimento <anderson@allelesecurity.com>
Closes: https://lore.kernel.org/netdev/37a477a6-d39e-486b-9577-3463f655a6b7@allelesecurity.com/
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240501213145.62261-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17 11:56:11 +02:00
..
bpfilter
netfilter netfilter: complete validation of user input 2024-04-17 11:18:25 +02:00
Kconfig tcp: configurable source port perturb table size 2022-11-16 13:02:04 +00:00
Makefile
af_inet.c inet: read sk->sk_family once in inet_recv_error() 2024-02-16 19:06:27 +01:00
ah4.c xfrm: ah: add extack to ah_init_state, ah6_init_state 2022-09-29 07:17:59 +02:00
arp.c arp: Prevent overflow in arp_req_get(). 2024-03-01 13:26:39 +01:00
bpf_tcp_ca.c bpf: Use 0 instead of NOT_INIT for btf_struct_access() writes 2022-09-10 17:27:32 -07:00
cipso_ipv4.c
datagram.c ipv4: fix data-races around inet->inet_id 2023-08-30 16:11:02 +02:00
devinet.c ipv4: properly combine dev_base_seq and ipv4.dev_addr_genid 2024-03-01 13:26:36 +01:00
esp4.c net: ipv4: fix return value check in esp_remove_trailer 2023-10-25 12:03:06 +02:00
esp4_offload.c xfrm: Linearize the skb after offloading if needed. 2023-06-28 11:12:29 +02:00
fib_frontend.c ipv4: Fix incorrect table ID in IOCTL path 2023-03-22 13:33:50 +01:00
fib_lookup.h
fib_notifier.c
fib_rules.c
fib_semantics.c ipv4/fib: send notify when delete source address routes 2023-10-25 12:03:11 +02:00
fib_trie.c ipv4/fib: send notify when delete source address routes 2023-10-25 12:03:11 +02:00
fou.c genetlink: start to validate reserved header bytes 2022-08-29 12:47:15 +01:00
gre_demux.c
gre_offload.c net: gro: skb_gro_header helper function 2022-08-25 10:33:21 +02:00
icmp.c icmp: prevent possible NULL dereferences from icmp_build_probe() 2024-05-02 16:29:23 +02:00
igmp.c ipv4: igmp: fix refcnt uaf issue when receiving igmp query packet 2023-12-08 08:51:17 +01:00
inet_connection_sock.c tcp: Fix bind() regression for v6-only wildcard and v4(-mapped-v6) non-wildcard addresses. 2024-04-10 16:28:29 +02:00
inet_diag.c inet_diag: annotate data-races around inet_diag_table[] 2024-03-26 18:20:31 -04:00
inet_fragment.c inet: inet_defrag: prevent sk release while still in use 2024-04-10 16:28:23 +02:00
inet_hashtables.c tcp: Fix refcnt handling in __inet_hash_connect(). 2024-03-26 18:20:59 -04:00
inet_timewait_sock.c tcp: Fix NEW_SYN_RECV handling in inet_twsk_purge() 2024-03-26 18:20:58 -04:00
inetpeer.c
ip_forward.c ip: Fix data-races around sysctl_ip_fwd_update_priority. 2022-07-15 11:49:55 +01:00
ip_fragment.c inet: inet_defrag: prevent sk release while still in use 2024-04-10 16:28:23 +02:00
ip_gre.c erspan: make sure erspan_base_hdr is present in skb->head 2024-04-10 16:28:27 +02:00
ip_input.c ipv4: ignore dst hint for multipath routes 2023-09-19 12:28:01 +02:00
ip_options.c
ip_output.c net: ipv4: fix a memleak in ip_setup_cork 2024-02-05 20:13:02 +00:00
ip_sockglue.c ipmr: fix kernel panic when forwarding mcast packets 2024-02-05 20:13:00 +00:00
ip_tunnel.c net: ip_tunnel: make sure to pull inner header in ip_tunnel_rcv() 2024-03-26 18:20:41 -04:00
ip_tunnel_core.c tunnels: fix out of bounds access when building IPv6 PMTU error 2024-02-16 19:06:26 +01:00
ip_vti.c ip_vti: fix potential slab-use-after-free in decode_session6 2023-08-23 17:52:32 +02:00
ipcomp.c xfrm: ipcomp: add extack to ipcomp{4,6}_init_state 2022-09-29 07:18:00 +02:00
ipconfig.c Driver core / kernfs changes for 6.0-rc1 2022-08-04 11:31:20 -07:00
ipip.c net: Add helper function to parse netlink msg of ip_tunnel_parm 2022-10-03 07:59:06 +01:00
ipmr.c ipmr: fix incorrect parameter validation in the ip_mroute_getsockopt() function 2024-03-26 18:20:42 -04:00
ipmr_base.c
metrics.c ipv4: prevent potential spectre v1 gadget in ip_metrics_convert() 2023-02-01 08:34:45 +01:00
netfilter.c
netlink.c
nexthop.c neighbour: switch to standard rcu, instead of rcu_bh 2023-10-10 22:00:42 +02:00
ping.c ping: Fix potentail NULL deref for /proc/net/icmp. 2023-04-13 16:55:24 +02:00
proc.c tcp: Don't allocate tcp_death_row outside of struct netns_ipv4. 2022-09-20 10:21:49 -07:00
protocol.c
raw.c ipv4: raw: Fix sending packets from raw sockets via IPsec tunnels 2024-03-26 18:21:00 -04:00
raw_diag.c raw: Fix NULL deref in raw_get_next(). 2023-04-13 16:55:23 +02:00
route.c ipv4: check for NULL idev in ip_route_use_hint() 2024-05-02 16:29:24 +02:00
syncookies.c tcp: fix cookie_init_timestamp() overflows 2023-11-20 11:51:54 +01:00
sysctl_net_ipv4.c tcp: enforce receive buffer memory limits by allowing the tcp window to shrink 2023-10-19 23:08:54 +02:00
tcp.c tcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV sockets 2024-05-17 11:56:11 +02:00
tcp_bbr.c bpf: Switch to new kfunc flags infrastructure 2022-07-21 20:59:42 -07:00
tcp_bic.c
tcp_bpf.c tcp_bpf: properly release resources on error paths 2023-10-25 12:03:13 +02:00
tcp_cdg.c Random number generator fixes for Linux 6.1-rc1. 2022-10-16 15:27:07 -07:00
tcp_cong.c
tcp_cubic.c bpf: Switch to new kfunc flags infrastructure 2022-07-21 20:59:42 -07:00
tcp_dctcp.c bpf: Switch to new kfunc flags infrastructure 2022-07-21 20:59:42 -07:00
tcp_dctcp.h
tcp_diag.c tcp: Access &tcp_hashinfo via net. 2022-09-20 10:21:49 -07:00
tcp_fastopen.c tcp: annotate data-races around fastopenq.max_qlen 2023-07-27 08:50:49 +02:00
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c
tcp_illinois.c
tcp_input.c tcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV sockets 2024-05-17 11:56:11 +02:00
tcp_ipv4.c tcp: Use refcount_inc_not_zero() in tcp_twsk_unique(). 2024-05-17 11:56:11 +02:00
tcp_lp.c
tcp_metrics.c tcp_metrics: do not create an entry from tcp_init_metrics() 2023-11-20 11:51:53 +01:00
tcp_minisocks.c rds: tcp: Fix use-after-free of net in reqsk_timer_handler(). 2024-03-26 18:20:58 -04:00
tcp_nv.c
tcp_offload.c tcp: gso: really support BIG TCP 2023-06-14 11:15:20 +02:00
tcp_output.c tcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV sockets 2024-05-17 11:56:11 +02:00
tcp_rate.c
tcp_recovery.c tcp: fix excessive TLP and RACK timeouts from HZ rounding 2023-10-25 12:03:06 +02:00
tcp_scalable.c
tcp_timer.c net: tcp: fix unexcepted socket die when snd_wnd is 0 2023-09-13 09:42:32 +02:00
tcp_ulp.c net/ulp: use consistent error code when blocking ULP 2023-01-24 07:24:43 +01:00
tcp_vegas.c
tcp_vegas.h
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tunnel4.c
udp.c udp: preserve the connected status if only UDP cmsg 2024-05-02 16:29:30 +02:00
udp_bpf.c bpf, sockmap: Fix an infinite loop error when len is 0 in tcp_bpf_recvmsg_parser() 2023-03-17 08:50:24 +01:00
udp_diag.c
udp_impl.h
udp_offload.c net: gro: add flush check in udp_gro_receive_segment 2024-05-17 11:56:02 +02:00
udp_tunnel_core.c udp: lockless UDP_ENCAP_L2TPINUDP / UDP_GRO 2024-01-10 17:10:28 +01:00
udp_tunnel_nic.c
udp_tunnel_stub.c
udplite.c udplite: Fix NULL pointer dereference in __sk_mem_raise_allocated(). 2023-05-30 14:03:20 +01:00
xfrm4_input.c xfrm: Preserve vlan tags for transport mode software GRO 2024-05-17 11:56:10 +02:00
xfrm4_output.c
xfrm4_policy.c
xfrm4_protocol.c
xfrm4_state.c
xfrm4_tunnel.c xfrm: tunnel: add extack to ipip_init_state, xfrm6_tunnel_init_state 2022-09-29 07:18:00 +02:00