remarkable-linux/net
Paolo Abeni 18bf9a7243 ip6_tunnel: be careful when accessing the inner header
[ Upstream commit 76c0ddd8c3 ]

the ip6 tunnel xmit ndo assumes that the processed skb always
contains an ip[v6] header, but syzbot has found a way to send
frames that fall short of this assumption, leading to the following splat:

BUG: KMSAN: uninit-value in ip6ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1307
[inline]
BUG: KMSAN: uninit-value in ip6_tnl_start_xmit+0x7d2/0x1ef0
net/ipv6/ip6_tunnel.c:1390
CPU: 0 PID: 4504 Comm: syz-executor558 Not tainted 4.16.0+ #87
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:683
  ip6ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1307 [inline]
  ip6_tnl_start_xmit+0x7d2/0x1ef0 net/ipv6/ip6_tunnel.c:1390
  __netdev_start_xmit include/linux/netdevice.h:4066 [inline]
  netdev_start_xmit include/linux/netdevice.h:4075 [inline]
  xmit_one net/core/dev.c:3026 [inline]
  dev_hard_start_xmit+0x5f1/0xc70 net/core/dev.c:3042
  __dev_queue_xmit+0x27ee/0x3520 net/core/dev.c:3557
  dev_queue_xmit+0x4b/0x60 net/core/dev.c:3590
  packet_snd net/packet/af_packet.c:2944 [inline]
  packet_sendmsg+0x7c70/0x8a30 net/packet/af_packet.c:2969
  sock_sendmsg_nosec net/socket.c:630 [inline]
  sock_sendmsg net/socket.c:640 [inline]
  ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046
  __sys_sendmmsg+0x42d/0x800 net/socket.c:2136
  SYSC_sendmmsg+0xc4/0x110 net/socket.c:2167
  SyS_sendmmsg+0x63/0x90 net/socket.c:2162
  do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x441819
RSP: 002b:00007ffe58ee8268 EFLAGS: 00000213 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441819
RDX: 0000000000000002 RSI: 0000000020000100 RDI: 0000000000000003
RBP: 00000000006cd018 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000402510
R13: 00000000004025a0 R14: 0000000000000000 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
  kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321
  slab_post_alloc_hook mm/slab.h:445 [inline]
  slab_alloc_node mm/slub.c:2737 [inline]
  __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369
  __kmalloc_reserve net/core/skbuff.c:138 [inline]
  __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206
  alloc_skb include/linux/skbuff.h:984 [inline]
  alloc_skb_with_frags+0x1d4/0xb20 net/core/skbuff.c:5234
  sock_alloc_send_pskb+0xb56/0x1190 net/core/sock.c:2085
  packet_alloc_skb net/packet/af_packet.c:2803 [inline]
  packet_snd net/packet/af_packet.c:2894 [inline]
  packet_sendmsg+0x6454/0x8a30 net/packet/af_packet.c:2969
  sock_sendmsg_nosec net/socket.c:630 [inline]
  sock_sendmsg net/socket.c:640 [inline]
  ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046
  __sys_sendmmsg+0x42d/0x800 net/socket.c:2136
  SYSC_sendmmsg+0xc4/0x110 net/socket.c:2167
  SyS_sendmmsg+0x63/0x90 net/socket.c:2162
  do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x3d/0xa2

This change addresses the issue adding the needed check before
accessing the inner header.

The ipv4 side of the issue is apparently there since the ipv4 over ipv6
initial support, and the ipv6 side predates git history.

Fixes: c4d3efafcc ("[IPV6] IP6TUNNEL: Add support to IPv4 over IPv6 tunnel.")
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot+3fde91d4d394747d6db4@syzkaller.appspotmail.com
Tested-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18 09:16:17 +02:00
..
6lowpan 6lowpan: iphc: reset mac_header after decompress to fix panic 2018-10-03 17:00:47 -07:00
9p net/9p: fix error path of p9_virtio_probe 2018-09-15 09:45:29 +02:00
802 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
8021q net: fix use-after-free in GRO with ESP 2018-07-22 14:28:44 +02:00
appletalk
atm atm: Preserve value of skb->truesize when accounting to vcc 2018-07-22 14:28:43 +02:00
ax25
batman-adv batman-adv: Fix multicast TT issues with bogus ROAM flags 2018-08-24 13:09:05 +02:00
bluetooth Bluetooth: Use lock_sock_nested in bt_accept_enqueue 2018-09-26 08:38:09 +02:00
bpf
bridge netfilter: ebtables: reject non-bridge targets 2018-07-22 14:28:49 +02:00
caif net: caif: Add a missing rcu_read_unlock() in caif_flow_cb 2018-09-05 09:26:27 +02:00
can
ceph libceph, ceph: avoid memory leak when specifying same option several times 2018-05-30 07:52:04 +02:00
core neighbour: confirm neigh entries when ARP packet is received 2018-09-29 03:06:01 -07:00
dcb net: dcb: For wild-card lookups, use priority -1, not 0 2018-09-19 22:43:43 +02:00
dccp dccp: fix undefined behavior with 'cwnd' shift in ccid2_cwnd_restart() 2018-08-22 07:46:08 +02:00
decnet
dns_resolver KEYS: DNS: fix parsing multiple options 2018-07-22 14:28:49 +02:00
dsa net: dsa: Do not suspend/resume closed slave_dev 2018-08-06 16:20:48 +02:00
ethernet
hsr
ieee802154 inet: frags: fix ip6frag_low_thresh boundary 2018-09-19 22:43:47 +02:00
ife net: sched: ife: check on metadata length 2018-04-29 11:33:13 +02:00
ipv4 udp4: fix IP_CMSG_CHECKSUM for connected sockets 2018-09-29 03:06:00 -07:00
ipv6 ip6_tunnel: be careful when accessing the inner header 2018-10-18 09:16:17 +02:00
ipx License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
iucv net/iucv: Free memory obtained by kzalloc 2018-03-31 18:10:41 +02:00
kcm kcm: Fix use-after-free caused by clonned sockets 2018-06-11 22:49:19 +02:00
key af_key: Always verify length of provided sadb_key 2018-06-16 09:45:14 +02:00
l2tp l2tp: use sk_dst_check() to avoid race on sk->sk_dst_cache 2018-08-22 07:46:08 +02:00
l3mdev
lapb
llc llc: use refcount_inc_not_zero() for llc_sap_find() 2018-08-22 07:46:08 +02:00
mac80211 mac80211: fix setting IEEE80211_KEY_FLAG_RX_MGMT for AP mode keys 2018-10-13 09:27:24 +02:00
mac802154 net: mac802154: tx: expand tailroom if necessary 2018-09-09 19:55:52 +02:00
mpls
ncsi
netfilter netfilter: nf_tables: release chain in flushing set 2018-10-10 08:54:23 +02:00
netlabel netlabel: If PF_INET6, check sk_buff ip header version 2018-05-30 07:52:40 +02:00
netlink netlink: Don't shift on 64 for ngroups 2018-08-09 12:16:38 +02:00
netrom net, netrom: convert nr_node.refcount from atomic_t to refcount_t 2017-07-04 22:35:17 +01:00
nfc NFC: Fix possible memory corruption when handling SHDLC I-Frame commands 2018-09-29 03:06:01 -07:00
nsh nsh: set mac len based on inner packet 2018-07-22 14:28:49 +02:00
openvswitch openvswitch: Don't swap table in nlattr_set() after OVS_ATTR_NESTED is found 2018-05-19 10:20:24 +02:00
packet packet: refine ring v3 block size test to hold one frame 2018-08-24 13:09:22 +02:00
phonet License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
psample
qrtr net: qrtr: Broadcast messages only from control port 2018-08-24 13:09:13 +02:00
rds rds: rds_ib_recv_alloc_cache() should call alloc_percpu_gfp() instead 2018-10-13 09:27:29 +02:00
rfkill rfkill: gpio: fix memory leak in probe error path 2018-05-16 10:10:26 +02:00
rose
rxrpc rxrpc: Fix user call ID check in rxrpc_service_prealloc_one 2018-08-06 16:20:48 +02:00
sched net/sched: act_sample: fix NULL dereference in the data path 2018-09-29 03:06:01 -07:00
sctp sctp: hold transport before accessing its asoc in sctp_transport_get_next 2018-09-15 09:45:25 +02:00
smc net/smc: no shutdown in state SMC_LISTEN 2018-08-24 13:09:22 +02:00
strparser strparser: Remove early eaten to fix full tcp receive buffer stall 2018-07-22 14:28:47 +02:00
sunrpc sunrpc: Don't use stack buffer with scatterlist 2018-09-15 09:45:26 +02:00
switchdev net: switchdev: Remove bridge bypass support from switchdev 2017-08-07 14:48:48 -07:00
tipc tipc: fix a missing rhashtable_walk_exit() 2018-09-15 09:45:25 +02:00
tls tls: possible hang when do_tcp_sendpages hits sndbuf is full case 2018-10-03 17:00:58 -07:00
unix License cleanup: add SPDX license identifiers to some files 2017-11-02 10:04:46 -07:00
vmw_vsock vsock: split dwork to avoid reinitializations 2018-08-22 07:46:08 +02:00
wimax
wireless cfg80211: fix a type issue in ieee80211_chandef_to_operating_class() 2018-10-10 08:54:21 +02:00
x25 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm xfrm: fix 'passing zero to ERR_PTR()' warning 2018-09-26 08:37:59 +02:00
compat.c net: support compat 64-bit time in {s,g}etsockopt 2018-05-19 10:20:24 +02:00
Kconfig
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
socket.c net: socket: fix potential spectre v1 gadget in socketcall 2018-08-06 16:20:48 +02:00
sysctl_net.c sysctl: Remove dead register_sysctl_root 2017-04-16 23:42:49 -05:00