linux/net
Eric Dumazet b6a37e5e25 inetpeer: fix uninit-value in inet_getpeer
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>
2018-04-09 10:57:35 -04:00
..
6lowpan
9p virtio: bugfixes 2018-02-15 14:29:27 -08:00
802
8021q vlan: also check phy_driver ts_info for vlan's real device 2018-04-01 20:53:50 -04:00
appletalk net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
atm net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
ax25 net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
batman-adv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-01 19:49:34 -04:00
bluetooth Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth 2018-04-08 17:19:15 -04:00
bpf bpf: fix null pointer deref in bpf_prog_test_run_xdp 2018-02-01 07:43:56 -08:00
bridge net: bridge: disable bridge MTU auto tuning if it was set manually 2018-03-31 22:19:00 -04:00
caif net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
can net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
ceph net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
core devlink: convert occ_get op to separate registration 2018-04-08 12:45:57 -04:00
dcb
dccp dccp: initialize ireq->ir_mark 2018-04-07 22:32:31 -04:00
decnet net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
dns_resolver net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
dsa net: dsa: Discard frames from unused ports 2018-04-08 10:34:49 -04:00
ethernet
hsr
ieee802154 inet: frags: fix ip6frag_low_thresh boundary 2018-04-04 12:04:59 -04:00
ife
ipv4 inetpeer: fix uninit-value in inet_getpeer 2018-04-09 10:57:35 -04:00
ipv6 net/ipv6: Increment OUTxxx counters after netfilter hook 2018-04-05 22:23:43 -04:00
iucv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-23 11:31:58 -04:00
kcm net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
key net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
l2tp net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
l3mdev
lapb
llc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-01 19:49:34 -04:00
mac80211 We have a fair number of patches, but many of them are from the 2018-03-29 16:23:26 -04:00
mac802154 net/mac802154: disambiguate mac80215 vs mac802154 trace events 2018-03-28 22:55:18 +02:00
mpls net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
ncsi net/ncsi: check for null return from call to nla_nest_start 2018-03-27 10:38:26 -04:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-01 19:49:34 -04:00
netlabel
netlink netlink: fix uninit-value in netlink_sendmsg 2018-04-07 22:32:31 -04:00
netrom net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
nfc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-02-19 18:46:11 -05:00
nsh
openvswitch ovs: Remove rtnl_lock() from ovs_exit_net() 2018-03-29 13:47:54 -04:00
packet net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
phonet net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
psample
qrtr Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-06 01:20:46 -05:00
rds net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
rfkill vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
rose net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
rxrpc rxrpc: Fix undefined packet handling 2018-04-04 11:04:08 -04:00
sched net_sched: fix a missing idr_remove() in u32_delete_key() 2018-04-07 12:36:45 -04:00
sctp sctp: sctp_sockaddr_af must check minimal addr length for AF_INET6 2018-04-08 12:29:41 -04:00
smc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-01 19:49:34 -04:00
strparser strparser: Fix sign of err codes 2018-03-27 11:00:18 -04:00
sunrpc net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
switchdev
tipc tipc: use the right skb in tipc_sk_fill_sock_diag() 2018-04-08 12:34:29 -04:00
tls tls: support for Inline tls record 2018-03-31 23:37:32 -04:00
unix af_unix: remove redundant lockdep class 2018-04-04 11:13:40 -04:00
vmw_vsock net: make getname() functions return length rather than use int* parameter 2018-02-12 14:15:04 -05:00
wimax
wireless Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-03-31 23:33:04 -04:00
x25 net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-01 19:49:34 -04:00
compat.c net: socket: add __compat_sys_...msg() helpers; remove in-kernel calls to compat syscalls 2018-04-02 20:15:20 +02:00
Kconfig Staging/IIO patches for 4.16-rc1 2018-02-01 09:51:57 -08:00
Makefile
socket.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-04-03 14:04:18 -07:00
sysctl_net.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00