remarkable-linux/net/ipv4
Eric Dumazet ac91ff2a5f inetpeer: fix uninit-value in inet_getpeer
commit b6a37e5e25 upstream.

syzbot/KMSAN reported that p->dtime was read while it was
not yet initialized in :

	delta = (__u32)jiffies - p->dtime;
	if (delta < ttl || !refcount_dec_if_one(&p->refcnt))
		gc_stack[i] = NULL;

This is a false positive, because the inetpeer wont be erased
from rb-tree if the refcount_dec_if_one(&p->refcnt) does not
succeed. And this wont happen before first inet_putpeer() call
for this inetpeer has been done, and ->dtime field is written
exactly before the refcount_dec_and_test(&p->refcnt).

The KMSAN report was :

BUG: KMSAN: uninit-value in inet_peer_gc net/ipv4/inetpeer.c:163 [inline]
BUG: KMSAN: uninit-value in inet_getpeer+0x1567/0x1e70 net/ipv4/inetpeer.c:228
CPU: 0 PID: 9494 Comm: syz-executor5 Not tainted 4.16.0+ #82
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
 inet_peer_gc net/ipv4/inetpeer.c:163 [inline]
 inet_getpeer+0x1567/0x1e70 net/ipv4/inetpeer.c:228
 inet_getpeer_v4 include/net/inetpeer.h:110 [inline]
 icmpv4_xrlim_allow net/ipv4/icmp.c:330 [inline]
 icmp_send+0x2b44/0x3050 net/ipv4/icmp.c:725
 ip_options_compile+0x237c/0x29f0 net/ipv4/ip_options.c:472
 ip_rcv_options net/ipv4/ip_input.c:284 [inline]
 ip_rcv_finish+0xda8/0x16d0 net/ipv4/ip_input.c:365
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_rcv+0x119d/0x16f0 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 netif_receive_skb_internal+0x49d/0x630 net/core/dev.c:4701
 netif_receive_skb+0x230/0x240 net/core/dev.c:4725
 tun_rx_batched drivers/net/tun.c:1555 [inline]
 tun_get_user+0x6d88/0x7580 drivers/net/tun.c:1962
 tun_chr_write_iter+0x1d4/0x330 drivers/net/tun.c:1990
 do_iter_readv_writev+0x7bb/0x970 include/linux/fs.h:1776
 do_iter_write+0x30d/0xd40 fs/read_write.c:932
 vfs_writev fs/read_write.c:977 [inline]
 do_writev+0x3c9/0x830 fs/read_write.c:1012
 SYSC_writev+0x9b/0xb0 fs/read_write.c:1085
 SyS_writev+0x56/0x80 fs/read_write.c:1082
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x455111
RSP: 002b:00007fae0365cba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 000000000000002e RCX: 0000000000455111
RDX: 0000000000000001 RSI: 00007fae0365cbf0 RDI: 00000000000000fc
RBP: 0000000020000040 R08: 00000000000000fc R09: 0000000000000000
R10: 000000000000002e R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000658 R14: 00000000006fc8e0 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314
 kmem_cache_alloc+0xaab/0xb90 mm/slub.c:2756
 inet_getpeer+0xed8/0x1e70 net/ipv4/inetpeer.c:210
 inet_getpeer_v4 include/net/inetpeer.h:110 [inline]
 ip4_frag_init+0x4d1/0x740 net/ipv4/ip_fragment.c:153
 inet_frag_alloc net/ipv4/inet_fragment.c:369 [inline]
 inet_frag_create net/ipv4/inet_fragment.c:385 [inline]
 inet_frag_find+0x7da/0x1610 net/ipv4/inet_fragment.c:418
 ip_find net/ipv4/ip_fragment.c:275 [inline]
 ip_defrag+0x448/0x67a0 net/ipv4/ip_fragment.c:676
 ip_check_defrag+0x775/0xda0 net/ipv4/ip_fragment.c:724
 packet_rcv_fanout+0x2a8/0x8d0 net/packet/af_packet.c:1447
 deliver_skb net/core/dev.c:1897 [inline]
 deliver_ptype_list_skb net/core/dev.c:1912 [inline]
 __netif_receive_skb_core+0x314a/0x4a80 net/core/dev.c:4545
 __netif_receive_skb net/core/dev.c:4627 [inline]
 netif_receive_skb_internal+0x49d/0x630 net/core/dev.c:4701
 netif_receive_skb+0x230/0x240 net/core/dev.c:4725
 tun_rx_batched drivers/net/tun.c:1555 [inline]
 tun_get_user+0x6d88/0x7580 drivers/net/tun.c:1962
 tun_chr_write_iter+0x1d4/0x330 drivers/net/tun.c:1990
 do_iter_readv_writev+0x7bb/0x970 include/linux/fs.h:1776
 do_iter_write+0x30d/0xd40 fs/read_write.c:932
 vfs_writev fs/read_write.c:977 [inline]
 do_writev+0x3c9/0x830 fs/read_write.c:1012
 SYSC_writev+0x9b/0xb0 fs/read_write.c:1085
 SyS_writev+0x56/0x80 fs/read_write.c:1082
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-16 10:10:24 +02:00
..
netfilter netfilter: compat: prepare xt_compat_init_offsets to return errors 2018-04-26 11:02:21 +02:00
af_inet.c net: accept UFO datagrams from tuntap and packet 2017-12-17 15:07:58 +01:00
ah4.c
arp.c arp: fix arp_filter on l3slave devices 2018-04-12 12:32:22 +02:00
cipso_ipv4.c tcp/dccp: fix ireq->opt races 2017-10-21 01:33:19 +01:00
datagram.c
devinet.c ipv4: igmp: guard against silly MTU values 2018-01-02 20:31:06 +01:00
esp4.c
esp4_offload.c esp: Fix GRO when the headers not fully in the linear part of the skb. 2018-02-25 11:07:46 +01:00
fib_frontend.c ipv4: Fix use-after-free when flushing FIB tables 2018-01-02 20:31:09 +01:00
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
fib_semantics.c route: check sysctl_fib_multipath_use_neigh earlier than hash 2018-04-12 12:32:27 +02:00
fib_trie.c
fou.c
gre_demux.c
gre_offload.c gso: fix payload length when gso_size is zero 2017-10-08 10:12:15 -07:00
icmp.c icmp: don't fail on fragment reassembly time exceeded 2017-12-20 10:10:37 +01:00
igmp.c net: igmp: add a missing rcu locking section 2018-02-13 10:19:47 +01:00
inet_connection_sock.c Revert "defer call to mem_cgroup_sk_alloc()" 2018-02-13 10:19:48 +01:00
inet_diag.c
inet_fragment.c net: Fix hlist corruptions in inet_evict_bucket() 2018-03-31 18:10:40 +02:00
inet_hashtables.c soreuseport: fix initialization race 2017-10-22 02:03:51 +01:00
inet_timewait_sock.c soreuseport: initialise timewait reuseport field 2018-05-16 10:10:24 +02:00
inetpeer.c inetpeer: fix uninit-value in inet_getpeer 2018-05-16 10:10:24 +02:00
ip_forward.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip_fragment.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip_gre.c ip_gre: fix potential memory leak in erspan_rcv 2018-03-24 11:01:27 +01:00
ip_input.c IPv4: early demux can return an error code 2017-10-01 03:55:47 +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
ip_sockglue.c net: Only honor ifindex in IP_PKTINFO if non-0 2018-03-31 18:10:41 +02:00
ip_tunnel.c net: don't call update_pmtu unconditionally 2018-05-09 09:51:48 +02:00
ip_tunnel_core.c
ip_vti.c net: don't call update_pmtu unconditionally 2018-05-09 09:51:48 +02:00
ipcomp.c
ipconfig.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ipip.c ipip: only increase err_count for some certain type icmp in ipip_err 2017-10-27 23:43:31 +09:00
ipmr.c
Kconfig ip: update policy routing config help 2017-10-12 22:57:11 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
netfilter.c
ping.c
proc.c
protocol.c
raw.c net: ipv4: fix for a race condition in raw_sendmsg 2018-01-02 20:31:08 +01:00
raw_diag.c
route.c ipv4: fix uninit-value in ip_route_output_key_hash_rcu() 2018-05-16 10:10:24 +02:00
syncookies.c tcp/dccp: fix ireq->opt races 2017-10-21 01:33:19 +01:00
sysctl_net_ipv4.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tcp.c tcp: clear tp->packets_out when purging write queue 2018-04-29 11:33:13 +02:00
tcp_bbr.c tcp_bbr: fix pacing_gain to always be unity when using lt_bw 2018-02-13 10:19:48 +01:00
tcp_bic.c
tcp_cdg.c
tcp_cong.c
tcp_cubic.c
tcp_dctcp.c
tcp_diag.c
tcp_fastopen.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c
tcp_illinois.c
tcp_input.c tcp: don't read out-of-bounds opsize 2018-04-29 11:33:11 +02:00
tcp_ipv4.c tcp md5sig: Use skb's saddr when replying to an incoming segment 2018-01-02 20:31:07 +01:00
tcp_lp.c
tcp_metrics.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tcp_minisocks.c tcp/dccp: block bh before arming time_wait timer 2017-12-17 15:07:57 +01:00
tcp_nv.c tcp_nv: fix potential integer overflow in tcpnv_acked 2018-04-26 11:02:13 +02:00
tcp_offload.c gso: validate gso_type in GSO handlers 2018-01-31 14:03:47 +01:00
tcp_output.c tcp_bbr: better deal with suboptimal GSO 2018-03-08 22:41:13 -08:00
tcp_probe.c
tcp_rate.c tcp: invalidate rate samples during SACK reneging 2018-01-02 20:31:09 +01:00
tcp_recovery.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tcp_scalable.c
tcp_timer.c tcp: purge write queue upon aborting the connection 2018-03-31 18:10:38 +02:00
tcp_ulp.c
tcp_vegas.c tcp: fix under-evaluated ssthresh in TCP Vegas 2017-12-25 14:26:30 +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
udp.c udplite: fix partial checksum initialization 2018-03-08 22:41:10 -08:00
udp_diag.c
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 gso: validate gso_type in GSO handlers 2018-01-31 14:03:47 +01:00
udp_tunnel.c
udplite.c
xfrm4_input.c xfrm: Reinject transport-mode packets through tasklet 2018-03-03 10:24:25 +01:00
xfrm4_mode_beet.c
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c
xfrm4_output.c
xfrm4_policy.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
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