linux-uconsole/net/ipv4
Eric Dumazet e521703487 tcp: fix a race in inet_diag_dump_icsk()
[ Upstream commit f0c928d878 ]

Alexei reported use after frees in inet_diag_dump_icsk() [1]

Because we use refcount_set() when various sockets are setup and
inserted into ehash, we also need to make sure inet_diag_dump_icsk()
wont race with the refcount_set() operations.

Jonathan Lemon sent a patch changing net_twsk_hashdance() but
other spots would need risky changes.

Instead, fix inet_diag_dump_icsk() as this bug came with
linux-4.10 only.

[1] Quoting Alexei :

First something iterating over sockets finds already freed tw socket:

refcount_t: increment on 0; use-after-free.
WARNING: CPU: 2 PID: 2738 at lib/refcount.c:153 refcount_inc+0x26/0x30
RIP: 0010:refcount_inc+0x26/0x30
RSP: 0018:ffffc90004c8fbc0 EFLAGS: 00010282
RAX: 000000000000002b RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88085ee9d680 RSI: ffff88085ee954c8 RDI: ffff88085ee954c8
RBP: ffff88010ecbd2c0 R08: 0000000000000000 R09: 000000000000174c
R10: ffffffff81e7c5a0 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8806ba9bf210 R14: ffffffff82304600 R15: ffff88010ecbd328
FS:  00007f81f5a7d700(0000) GS:ffff88085ee80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f81e2a95000 CR3: 000000069b2eb006 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 inet_diag_dump_icsk+0x2b3/0x4e0 [inet_diag]  // sock_hold(sk); in net/ipv4/inet_diag.c:1002
 ? kmalloc_large_node+0x37/0x70
 ? __kmalloc_node_track_caller+0x1cb/0x260
 ? __alloc_skb+0x72/0x1b0
 ? __kmalloc_reserve.isra.40+0x2e/0x80
 __inet_diag_dump+0x3b/0x80 [inet_diag]
 netlink_dump+0x116/0x2a0
 netlink_recvmsg+0x205/0x3c0
 sock_read_iter+0x89/0xd0
 __vfs_read+0xf7/0x140
 vfs_read+0x8a/0x140
 SyS_read+0x3f/0xa0
 do_syscall_64+0x5a/0x100

then a minute later twsk timer fires and hits two bad refcnts
for this freed socket:

refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 31 PID: 0 at lib/refcount.c:228 refcount_dec+0x2e/0x40
Modules linked in:
RIP: 0010:refcount_dec+0x2e/0x40
RSP: 0018:ffff88085f5c3ea8 EFLAGS: 00010296
RAX: 000000000000002c RBX: ffff88010ecbd2c0 RCX: 000000000000083f
RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000003f
RBP: ffffc90003c77280 R08: 0000000000000000 R09: 00000000000017d3
R10: ffffffff81e7c5a0 R11: 0000000000000000 R12: ffffffff82ad2d80
R13: ffffffff8182de00 R14: ffff88085f5c3ef8 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88085f5c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbe42685250 CR3: 0000000002209001 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 inet_twsk_kill+0x9d/0xc0  // inet_twsk_bind_unhash(tw, hashinfo);
 call_timer_fn+0x29/0x110
 run_timer_softirq+0x36b/0x3a0

refcount_t: underflow; use-after-free.
WARNING: CPU: 31 PID: 0 at lib/refcount.c:187 refcount_sub_and_test+0x46/0x50
RIP: 0010:refcount_sub_and_test+0x46/0x50
RSP: 0018:ffff88085f5c3eb8 EFLAGS: 00010296
RAX: 0000000000000026 RBX: ffff88010ecbd2c0 RCX: 000000000000083f
RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000003f
RBP: ffff88010ecbd358 R08: 0000000000000000 R09: 000000000000185b
R10: ffffffff81e7c5a0 R11: 0000000000000000 R12: ffff88010ecbd358
R13: ffffffff8182de00 R14: ffff88085f5c3ef8 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88085f5c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbe42685250 CR3: 0000000002209001 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 inet_twsk_put+0x12/0x20  // inet_twsk_put(tw);
 call_timer_fn+0x29/0x110
 run_timer_softirq+0x36b/0x3a0

Fixes: 67db3e4bfb ("tcp: no longer hold ehash lock while calling tcp_get_info()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Alexei Starovoitov <ast@kernel.org>
Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09 17:38:33 +01:00
..
bpfilter bpfilter: remove trailing newline 2018-07-24 14:10:42 -07:00
netfilter netfilter: nat: fix double register in masquerade modules 2018-12-17 09:24:37 +01:00
af_inet.c gso_segment: Reset skb->mac_len after modifying network header 2018-09-13 12:09:32 -07:00
ah4.c net: use -ENOSPC for transient busy indication 2017-11-03 22:11:17 +08:00
arp.c proc: introduce proc_create_net{,_data} 2018-05-16 07:24:30 +02:00
cipso_ipv4.c net/ipv4: defensive cipso option parsing 2018-11-13 11:08:41 -08:00
datagram.c
devinet.c route: add support for directed broadcast forwarding 2018-07-29 12:37:06 -07:00
esp4.c esp4: remove redundant initialization of pointer esph 2018-02-13 13:59:03 +01:00
esp4_offload.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2018-07-27 09:33:37 -07:00
fib_frontend.c net: ipv4: update fnhe_pmtu when first hop's MTU changes 2018-10-10 22:44:46 -07:00
fib_lookup.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fib_notifier.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fib_rules.c net: fib_rules: add extack support 2018-04-23 10:21:24 -04:00
fib_semantics.c net: ipv4: update fnhe_pmtu when first hop's MTU changes 2018-10-10 22:44:46 -07:00
fib_trie.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
fou.c Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-07-03 10:29:26 +09:00
gre_demux.c
gre_offload.c Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-07-03 10:29:26 +09:00
icmp.c ipv4: ipcm_cookie initializers 2018-07-07 10:58:49 +09:00
igmp.c igmp: fix incorrect unsolicit report count after link down and up 2018-09-02 13:39:37 -07:00
inet_connection_sock.c inet: make sure to grab rcu_read_lock before using ireq->ireq_opt 2018-10-02 15:52:12 -07:00
inet_diag.c tcp: fix a race in inet_diag_dump_icsk() 2019-01-09 17:38:33 +01:00
inet_fragment.c inet: frags: better deal with smp races 2018-11-23 08:17:05 +01:00
inet_hashtables.c bpf: Enable BPF_PROG_TYPE_SK_REUSEPORT bpf prog in reuseport selection 2018-08-11 01:58:46 +02:00
inet_timewait_sock.c soreuseport: initialise timewait reuseport field 2018-04-07 22:32:32 -04:00
inetpeer.c inetpeer: fix uninit-value in inet_getpeer 2018-04-09 10:57:35 -04:00
ip_forward.c net: clear skb->tstamp in forwarding paths 2019-01-09 17:38:31 +01:00
ip_fragment.c net: ipv4: do not handle duplicate fragments as overlapping 2019-01-09 17:38:32 +01:00
ip_gre.c ip: validate header length on virtual device xmit 2019-01-09 17:38:31 +01:00
ip_input.c net: use skb_list_del_init() to remove from RX sublists 2018-12-17 09:24:27 +01:00
ip_options.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip_output.c Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-07-24 19:21:58 -07:00
ip_sockglue.c ipv4: fix use-after-free in ip_cmsg_recv_dstaddr() 2018-10-02 22:32:05 -07:00
ip_tunnel.c ip: validate header length on virtual device xmit 2019-01-09 17:38:31 +01:00
ip_tunnel_core.c ip_tunnel: don't force DF when MTU is locked 2018-11-23 08:17:02 +01:00
ip_vti.c ip: validate header length on virtual device xmit 2019-01-09 17:38:31 +01:00
ipcomp.c
ipconfig.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
ipip.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
ipmr.c ipv4: Fix potential Spectre v1 vulnerability 2019-01-09 17:38:31 +01:00
ipmr_base.c net: ipmr: fix unresolved entry dumps 2018-10-17 22:35:42 -07:00
Kconfig net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
Makefile net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
metrics.c net: metrics: add proper netlink validation 2018-06-05 12:29:43 -04:00
netfilter.c netfilter: utils: move nf_ip_checksum* from ipv4 to utils 2018-07-16 17:51:48 +02:00
netlink.c ipv4: support sport, dport and ip_proto in RTM_GETROUTE 2018-05-23 15:14:12 -04:00
ping.c net: add helpers checking if socket can be bound to nonlocal address 2018-08-01 09:50:04 -07:00
proc.c ip: discard IPv4 datagrams with overlapping segments. 2018-08-05 17:16:46 -07:00
protocol.c
raw.c ip: remove tx_flags from ipcm_cookie and use same logic for v4 and v6 2018-07-07 10:58:49 +09:00
raw_diag.c
route.c net: ipv4: don't let PMTU updates increase route MTU 2018-10-10 22:44:46 -07:00
syncookies.c net/ipv4: disable SMC TCP option with SYN Cookies 2018-03-25 20:53:54 -04:00
sysctl_net_ipv4.c net-tcp: /proc/sys/net/ipv4/tcp_probe_interval is a u32 not int 2018-09-26 20:33:21 -07:00
tcp.c tcp: do not release socket ownership in tcp_close() 2018-12-01 09:37:28 +01:00
tcp_bbr.c tcp_bbr: apply PROBE_RTT cwnd cap even if acked==0 2018-08-22 21:45:32 -07:00
tcp_bic.c
tcp_cdg.c tcp: cdg: make struct tcp_cdg static 2017-10-16 21:24:25 +01:00
tcp_cong.c tcp: Namespace-ify sysctl_tcp_default_congestion_control 2017-11-15 14:09:52 +09:00
tcp_cubic.c
tcp_dctcp.c tcp: avoid resetting ACK timer in DCTCP 2018-08-11 11:31:35 -07:00
tcp_diag.c net: sock: replace sk_state_load with inet_sk_state_load and remove sk_state_store 2017-12-20 14:00:25 -05:00
tcp_fastopen.c tcp: pause Fast Open globally after third consecutive timeout 2017-12-13 15:51:12 -05:00
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c
tcp_illinois.c net/tcp/illinois: replace broken algorithm reference link 2018-02-28 12:03:47 -05:00
tcp_input.c tcp: defer SACK compression after DupThresh 2018-12-05 19:32:00 +01:00
tcp_ipv4.c inet: make sure to grab rcu_read_lock before using ireq->ireq_opt 2018-10-02 15:52:12 -07:00
tcp_lp.c
tcp_metrics.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
tcp_minisocks.c tcp: do not restart timewait timer on rst reception 2018-08-31 23:10:35 -07:00
tcp_nv.c tcp_nv: fix potential integer overflow in tcpnv_acked 2018-01-31 10:26:30 -05:00
tcp_offload.c tcp: Don't coalesce decrypted and encrypted SKBs 2018-07-16 00:12:09 -07:00
tcp_output.c tcp: lack of available data can also cause TSO defer 2018-12-17 09:24:42 +01:00
tcp_rate.c tcp: expose both send and receive intervals for rate sample 2018-07-11 23:01:56 -07:00
tcp_recovery.c tcp: add stat of data packet reordering events 2018-08-01 09:56:10 -07:00
tcp_scalable.c
tcp_timer.c tcp: defer SACK compression after DupThresh 2018-12-05 19:32:00 +01:00
tcp_ulp.c tcp, ulp: fix leftover icsk_ulp_ops preventing sock from reattach 2018-08-16 14:58:08 -07:00
tcp_vegas.c tcp: fix under-evaluated ssthresh in TCP Vegas 2017-09-29 06:07:00 +01:00
tcp_vegas.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tunnel4.c inet: whitespace cleanup 2018-02-28 11:43:28 -05:00
udp.c net: udp: fix handling of CHECKSUM_COMPLETE packets 2018-11-04 14:50:51 +01:00
udp_diag.c udp: fix rx queue len reported by diag and proc interface 2018-06-08 19:55:15 -04:00
udp_impl.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
udp_offload.c Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-07-03 10:29:26 +09:00
udp_tunnel.c
udplite.c proc: introduce proc_create_net{,_data} 2018-05-16 07:24:30 +02:00
xfrm4_input.c xfrm: reset transport header back to network header after all input transforms ahave been applied 2018-09-04 10:26:30 +02:00
xfrm4_mode_beet.c
xfrm4_mode_transport.c xfrm: reset transport header back to network header after all input transforms ahave been applied 2018-09-04 10:26:30 +02:00
xfrm4_mode_tunnel.c xfrm: Verify MAC header exists before overwriting eth_hdr(skb)->h_proto 2018-03-07 10:54:29 +01:00
xfrm4_output.c net: xfrm: use skb_gso_validate_network_len() to check gso sizes 2018-03-04 17:49:17 -05:00
xfrm4_policy.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
xfrm4_protocol.c
xfrm4_state.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm4_tunnel.c