linux-stable/net/ipv4
Kuniyuki Iwashima 1796ca9c6f 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 11:43:53 +02:00
..
bpfilter
netfilter treewide: Remove uninitialized_var() usage 2023-06-09 10:29:01 +02:00
Kconfig tcp: configurable source port perturb table size 2022-12-08 11:23:00 +01:00
Makefile
af_inet.c tcp: add annotations around sk->sk_shutdown accesses 2024-03-01 13:13:34 +01:00
ah4.c
arp.c ipv4: Invalidate neighbour for broadcast address upon address addition 2022-04-15 14:18:33 +02:00
cipso_ipv4.c cipso: Fix data-races around sysctl. 2022-07-21 20:59:20 +02:00
datagram.c
devinet.c ipv4: properly combine dev_base_seq and ipv4.dev_addr_genid 2024-03-01 13:13:37 +01:00
esp4.c net: ipv4: fix return value check in esp_remove_trailer 2023-10-25 11:53:21 +02:00
esp4_offload.c xfrm: Linearize the skb after offloading if needed. 2023-06-28 10:18:38 +02:00
fib_frontend.c ipv4: Fix incorrect table ID in IOCTL path 2023-03-22 13:28:06 +01:00
fib_lookup.h
fib_notifier.c
fib_rules.c ipv6: fix memory leak in fib6_rule_suppress 2021-12-08 09:01:13 +01:00
fib_semantics.c ipv4: fib: annotate races around nh->nh_saddr_genid and nh->nh_saddr 2023-10-25 11:53:21 +02:00
fib_trie.c ipv4: annotate data-races around fi->fib_dead 2023-09-23 10:59:58 +02:00
fou.c
gre_demux.c
gre_offload.c
icmp.c icmp: guard against too small mtu 2023-04-20 12:07:33 +02:00
igmp.c ipv4: igmp: fix refcnt uaf issue when receiving igmp query packet 2023-12-08 08:44:27 +01:00
inet_connection_sock.c tcp: properly terminate timers for kernel sockets 2024-04-13 12:51:33 +02:00
inet_diag.c inet_diag: fix kernel-infoleak for UDP sockets 2021-12-22 09:29:36 +01:00
inet_fragment.c inet: frags: annotate races around fqdir->dead and fqdir->high_thresh 2022-01-27 09:19:54 +01:00
inet_hashtables.c Revert "tcp: avoid the lookup process failing to get sk in ehash table" 2023-07-27 08:37:44 +02:00
inet_timewait_sock.c tcp: Fix NEW_SYN_RECV handling in inet_twsk_purge() 2024-05-02 16:18:37 +02:00
inetpeer.c inetpeer: Fix data-races around sysctl. 2022-07-21 20:59:20 +02:00
ip_forward.c
ip_fragment.c inet: frags: annotate races around fqdir->dead and fqdir->high_thresh 2022-01-27 09:19:54 +01:00
ip_gre.c ip_gre: do not report erspan version on GRE interface 2024-04-13 12:51:40 +02:00
ip_input.c tcp/udp: Make early_demux back namespacified. 2022-11-10 17:57:55 +01:00
ip_options.c
ip_output.c net: ipv4: fix a memleak in ip_setup_cork 2024-02-23 08:25:05 +01:00
ip_sockglue.c ipv{4,6}/raw: fix output xfrm lookup wrt protocol 2023-06-05 08:17:33 +02:00
ip_tunnel.c net: ip_tunnel: make sure to pull inner header in ip_tunnel_rcv() 2024-03-26 18:22:17 -04:00
ip_tunnel_core.c
ip_vti.c ip_vti: fix potential slab-use-after-free in decode_session6 2023-08-30 16:27:16 +02:00
ipcomp.c
ipconfig.c net: ipconfig: Don't override command-line hostnames or domains 2021-06-18 09:58:59 +02:00
ipip.c
ipmr.c ipmr,ip6mr: acquire RTNL before calling ip[6]mr_free_table() on failure path 2022-02-16 12:52:51 +01:00
ipmr_base.c
metrics.c ipv4: prevent potential spectre v1 gadget in ip_metrics_convert() 2023-02-06 07:52:45 +01:00
netfilter.c
netlink.c
nexthop.c nh: fix scope used to find saddr when adding non gw nh 2022-11-03 23:56:56 +09:00
ping.c ping: fix address binding wrt vrf 2022-05-18 09:47:28 +02:00
proc.c
protocol.c
raw.c ipv{4,6}/raw: fix output xfrm lookup wrt protocol 2023-06-05 08:17:33 +02:00
raw_diag.c
route.c ipv4/route: avoid unused-but-set-variable warning 2024-05-02 16:18:28 +02:00
syncookies.c tcp: fix cookie_init_timestamp() overflows 2023-11-20 10:30:10 +01:00
sysctl_net_ipv4.c tcp/udp: Make early_demux back namespacified. 2022-11-10 17:57:55 +01:00
tcp.c tcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV sockets 2024-05-17 11:43:53 +02:00
tcp_bbr.c tcp_bbr: fix u32 wrap bug in round logic if bbr_init() called after 2B packets 2021-08-18 08:57:01 +02:00
tcp_bic.c
tcp_bpf.c bpf, sockmap: Fix data loss caused by using apply_bytes on ingress redirect 2023-01-18 11:41:08 +01:00
tcp_cdg.c tcp: cdg: allow tcp_cdg_release() to be called multiple times 2022-11-25 17:42:21 +01:00
tcp_cong.c net: Only allow init netns to set default tcp cong to a restricted algo 2021-05-14 09:44:33 +02:00
tcp_cubic.c tcp_cubic: fix spurious Hystart ACK train detections for not-cwnd-limited flows 2021-12-01 09:23:33 +01:00
tcp_dctcp.c
tcp_dctcp.h
tcp_diag.c
tcp_fastopen.c tcp: annotate data-races around fastopenq.max_qlen 2023-07-27 08:37:45 +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 11:43:53 +02:00
tcp_ipv4.c tcp: Use refcount_inc_not_zero() in tcp_twsk_unique(). 2024-05-17 11:43:53 +02:00
tcp_lp.c
tcp_metrics.c tcp_metrics: do not create an entry from tcp_init_metrics() 2023-11-20 10:30:09 +01:00
tcp_minisocks.c tcp: tcp_check_req() can be called from process context 2023-03-11 16:44:12 +01:00
tcp_nv.c
tcp_offload.c net, gro: Set inner transport header offset in tcp/udp GRO hook 2021-08-12 13:20:56 +02:00
tcp_output.c tcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV sockets 2024-05-17 11:43:53 +02:00
tcp_rate.c tcp: ensure to use the most recently sent skb when filling the rate sample 2022-05-09 09:03:24 +02:00
tcp_recovery.c tcp: fix excessive TLP and RACK timeouts from HZ rounding 2023-10-25 11:53:21 +02:00
tcp_scalable.c
tcp_timer.c net: fix the RTO timer retransmitting skb every 1ms if linear option is enabled 2023-08-30 16:27:19 +02:00
tcp_ulp.c
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 16:18:37 +02:00
udp_diag.c
udp_impl.h
udp_offload.c net, gro: Set inner transport header offset in tcp/udp GRO hook 2021-08-12 13:20:56 +02:00
udp_tunnel.c net/tunnel: wait until all sk_user_data reader finish before releasing the sock 2023-01-18 11:41:14 +01:00
udplite.c udplite: Fix NULL pointer dereference in __sk_mem_raise_allocated(). 2023-05-30 12:44:09 +01:00
xfrm4_input.c xfrm: Preserve vlan tags for transport mode software GRO 2024-05-17 11:43:53 +02:00
xfrm4_output.c
xfrm4_policy.c
xfrm4_protocol.c net: xfrm: unexport __init-annotated xfrm4_protocol_init() 2022-06-14 18:11:58 +02:00
xfrm4_state.c
xfrm4_tunnel.c