linux/net
Eric Dumazet fade445f39 tcp: deny tcp_disconnect() when threads are waiting
[ Upstream commit 4faeee0cf8 ]

Historically connect(AF_UNSPEC) has been abused by syzkaller
and other fuzzers to trigger various bugs.

A recent one triggers a divide-by-zero [1], and Paolo Abeni
was able to diagnose the issue.

tcp_recvmsg_locked() has tests about sk_state being not TCP_LISTEN
and TCP REPAIR mode being not used.

Then later if socket lock is released in sk_wait_data(),
another thread can call connect(AF_UNSPEC), then make this
socket a TCP listener.

When recvmsg() is resumed, it can eventually call tcp_cleanup_rbuf()
and attempt a divide by 0 in tcp_rcv_space_adjust() [1]

This patch adds a new socket field, counting number of threads
blocked in sk_wait_event() and inet_wait_for_connect().

If this counter is not zero, tcp_disconnect() returns an error.

This patch adds code in blocking socket system calls, thus should
not hurt performance of non blocking ones.

Note that we probably could revert commit 499350a5a6 ("tcp:
initialize rcv_mss to TCP_MIN_MSS instead of 0") to restore
original tcpi_rcv_mss meaning (was 0 if no payload was ever
received on a socket)

[1]
divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 13832 Comm: syz-executor.5 Not tainted 6.3.0-rc4-syzkaller-00224-g00c7b5f4ddc5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
RIP: 0010:tcp_rcv_space_adjust+0x36e/0x9d0 net/ipv4/tcp_input.c:740
Code: 00 00 00 00 fc ff df 4c 89 64 24 48 8b 44 24 04 44 89 f9 41 81 c7 80 03 00 00 c1 e1 04 44 29 f0 48 63 c9 48 01 e9 48 0f af c1 <49> f7 f6 48 8d 04 41 48 89 44 24 40 48 8b 44 24 30 48 c1 e8 03 48
RSP: 0018:ffffc900033af660 EFLAGS: 00010206
RAX: 4a66b76cbade2c48 RBX: ffff888076640cc0 RCX: 00000000c334e4ac
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000001
RBP: 00000000c324e86c R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880766417f8
R13: ffff888028fbb980 R14: 0000000000000000 R15: 0000000000010344
FS: 00007f5bffbfe700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32f25000 CR3: 000000007ced0000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
tcp_recvmsg_locked+0x100e/0x22e0 net/ipv4/tcp.c:2616
tcp_recvmsg+0x117/0x620 net/ipv4/tcp.c:2681
inet6_recvmsg+0x114/0x640 net/ipv6/af_inet6.c:670
sock_recvmsg_nosec net/socket.c:1017 [inline]
sock_recvmsg+0xe2/0x160 net/socket.c:1038
____sys_recvmsg+0x210/0x5a0 net/socket.c:2720
___sys_recvmsg+0xf2/0x180 net/socket.c:2762
do_recvmmsg+0x25e/0x6e0 net/socket.c:2856
__sys_recvmmsg net/socket.c:2935 [inline]
__do_sys_recvmmsg net/socket.c:2958 [inline]
__se_sys_recvmmsg net/socket.c:2951 [inline]
__x64_sys_recvmmsg+0x20f/0x260 net/socket.c:2951
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5c0108c0f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5bffbfe168 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f5c011ac050 RCX: 00007f5c0108c0f9
RDX: 0000000000000001 RSI: 0000000020000bc0 RDI: 0000000000000003
RBP: 00007f5c010e7b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000122 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5c012cfb1f R14: 00007f5bffbfe300 R15: 0000000000022000
</TASK>

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@googlegroups.com>
Reported-by: Paolo Abeni <pabeni@redhat.com>
Diagnosed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20230526163458.2880232-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-09 10:32:17 +02:00
..
6lowpan
9p 9p/xen : Fix use after free bug in xen_9pfs_front_remove due to race condition 2023-04-20 12:13:53 +02:00
802 mrp: introduce active flags to prevent UAF when applicant uninit 2022-12-31 13:14:42 +01:00
8021q vlan: fix a potential uninit-value in vlan_dev_hard_start_xmit() 2023-05-24 17:36:52 +01:00
appletalk
atm net/atm: fix proc_mpc_write incorrect return value 2022-10-29 10:12:55 +02:00
ax25 net: ax25: Fix deadlock caused by skb_recv_datagram in ax25_recvmsg 2022-06-22 14:22:01 +02:00
batman-adv batman-adv: Use netif_rx_any_context() any. 2022-07-29 17:25:07 +02:00
bluetooth bluetooth: Add cmd validity checks at the start of hci_sock_ioctl() 2023-06-05 09:21:24 +02:00
bpf bpf: Move skb->len == 0 checks into __bpf_redirect 2022-12-31 13:14:11 +01:00
bpfilter
bridge bridge: always declare tunnel functions 2023-05-24 17:36:52 +01:00
caif net: caif: Fix use-after-free in cfusbl_device_notify() 2023-03-17 08:48:54 +01:00
can can: isotp: recvmsg(): allow MSG_CMSG_COMPAT flag 2023-05-24 17:36:53 +01:00
ceph libceph: fix potential use-after-free on linger ping and resends 2022-05-25 09:57:28 +02:00
core xdp: xdp_mem_allocator can be NULL in trace_mem_connect(). 2023-06-05 09:21:23 +02:00
dcb net: dcb: disable softirqs in dcbnl_flush_dev() 2022-03-08 19:12:52 +01:00
dccp dccp: Call inet6_destroy_sock() via sk->sk_destruct(). 2023-04-26 13:51:54 +02:00
decnet net: Fix data-races around sysctl_[rw]mem(_offset)?. 2022-08-03 12:03:51 +02:00
dns_resolver
dsa net: dsa: tag_brcm: legacy: fix daisy-chained switches 2023-03-30 12:47:48 +02:00
ethernet
ethtool ethtool: Fix uninitialized number of lanes 2023-05-17 11:50:18 +02:00
hsr hsr: ratelimit only when errors are printed 2023-04-05 11:25:02 +02:00
ieee802154 net: ieee802154: fix error return code in dgram_bind() 2022-11-03 23:59:14 +09:00
ife
ipv4 tcp: deny tcp_disconnect() when threads are waiting 2023-06-09 10:32:17 +02:00
ipv6 ipv{4,6}/raw: fix output xfrm lookup wrt protocol 2023-06-05 09:21:26 +02:00
iucv net/iucv: Fix size of interrupt data 2023-03-22 13:31:28 +01:00
kcm kcm: close race conditions on sk_receive_queue 2022-11-26 09:24:50 +01:00
key af_key: Reject optional tunnel/BEET mode templates in outbound policies 2023-05-24 17:36:49 +01:00
l2tp inet6: Remove inet6_destroy_sock() in sk->sk_prot->destroy(). 2023-04-26 13:51:54 +02:00
l3mdev l3mdev: l3mdev_master_upper_ifindex_by_index_rcu should be using netdev_master_upper_dev_get_rcu 2022-04-27 14:38:53 +02:00
lapb
llc net: deal with most data-races in sk_wait_event() 2023-05-24 17:36:42 +01:00
mac80211 wifi: mac80211: fix min center freq offset tracing 2023-05-24 17:36:51 +01:00
mac802154 mac802154: fix missing INIT_LIST_HEAD in ieee802154_if_add() 2022-12-14 11:37:25 +01:00
mctp net: mctp: purge receive queues on sk destruction 2023-02-06 07:59:02 +01:00
mpls net: mpls: fix stale pointer if allocation fails during device rename 2023-02-22 12:57:09 +01:00
mptcp inet6: Remove inet6_destroy_sock() in sk->sk_prot->destroy(). 2023-04-26 13:51:54 +02:00
ncsi net/ncsi: clear Tx enable mode when handling a Config required AEN 2023-05-17 11:50:16 +02:00
netfilter netfilter: ctnetlink: Support offloaded conntrack entry deletion 2023-06-05 09:21:26 +02:00
netlabel netlabel: fix out-of-bounds memory accesses 2022-04-13 20:59:10 +02:00
netlink netlink: annotate accesses to nlk->cb_running 2023-05-24 17:36:42 +01:00
netrom netrom: fix info-leak in nr_write_internal() 2023-06-09 10:32:16 +02:00
nfc nfc: change order inside nfc_se_io error path 2023-03-17 08:48:49 +01:00
nsh net: nsh: Use correct mac_offset to unwind gso skb in nsh_gso_segment() 2023-05-24 17:36:51 +01:00
openvswitch net: openvswitch: fix possible memory leak in ovs_meter_cmd_set() 2023-02-22 12:57:09 +01:00
packet af_packet: do not use READ_ONCE() in packet_bind() 2023-06-09 10:32:17 +02:00
phonet phonet: refcount leak in pep_sock_accep 2022-01-11 15:35:16 +01:00
psample
qrtr net: qrtr: Fix an uninit variable access bug in qrtr_tx_resume() 2023-04-20 12:13:53 +02:00
rds rds: rds_rm_zerocopy_callback() correct order for list_add_tail() 2023-03-10 09:39:16 +01:00
rfkill rfkill: make new event layout opt-in 2022-04-08 14:23:00 +02:00
rose net/rose: Fix to not accept on connected socket 2023-02-22 12:57:02 +01:00
rxrpc rxrpc: Fix hard call timeout units 2023-05-17 11:50:17 +02:00
sched net/sched: act_mirred: Add carrier check 2023-05-17 11:50:17 +02:00
sctp sctp: fix an issue that plpmtu can never go to complete state 2023-05-30 13:55:33 +01:00
smc net: deal with most data-races in sk_wait_event() 2023-05-24 17:36:42 +01:00
strparser
sunrpc SUNRPC: Fix trace_svc_register() call site 2023-05-24 17:36:51 +01:00
switchdev
tipc tipc: check the bearer min mtu properly when setting it by netlink 2023-05-24 17:36:51 +01:00
tls net: deal with most data-races in sk_wait_event() 2023-05-24 17:36:42 +01:00
unix af_unix: Fix data races around sk->sk_shutdown. 2023-05-24 17:36:42 +01:00
vmw_vsock vsock: avoid to close connected socket after the timeout 2023-05-24 17:36:49 +01:00
wireless wifi: cfg80211: Partial revert "wifi: cfg80211: Fix use after free for wext" 2023-03-13 10:20:37 +01:00
x25 net/x25: Fix to not accept on connected socket 2023-02-09 11:26:40 +01:00
xdp xsk: Fix unaligned descriptor validation 2023-05-11 23:00:27 +09:00
xfrm Revert "Fix XFRM-I support for nested ESP tunnels" 2023-05-24 17:36:48 +01:00
compat.c
devres.c
Kconfig
Makefile
socket.c net: annotate sk->sk_err write from do_recvmmsg() 2023-05-24 17:36:42 +01:00
sysctl_net.c