linux-stable/net
Paolo Abeni 52f0a5ff60 ipv6: the entire IPv6 header chain must fit the first fragment
[ Upstream commit 10b8a3de60 ]

While building ipv6 datagram we currently allow arbitrary large
extheaders, even beyond pmtu size. The syzbot has found a way
to exploit the above to trigger the following splat:

kernel BUG at ./include/linux/skbuff.h:2073!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
    (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 4230 Comm: syzkaller672661 Not tainted 4.16.0-rc2+ #326
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__skb_pull include/linux/skbuff.h:2073 [inline]
RIP: 0010:__ip6_make_skb+0x1ac8/0x2190 net/ipv6/ip6_output.c:1636
RSP: 0018:ffff8801bc18f0f0 EFLAGS: 00010293
RAX: ffff8801b17400c0 RBX: 0000000000000738 RCX: ffffffff84f01828
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8801b415ac18
RBP: ffff8801bc18f360 R08: ffff8801b4576844 R09: 0000000000000000
R10: ffff8801bc18f380 R11: ffffed00367aee4e R12: 00000000000000d6
R13: ffff8801b415a740 R14: dffffc0000000000 R15: ffff8801b45767c0
FS:  0000000001535880(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000b000 CR3: 00000001b4123001 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  ip6_finish_skb include/net/ipv6.h:969 [inline]
  udp_v6_push_pending_frames+0x269/0x3b0 net/ipv6/udp.c:1073
  udpv6_sendmsg+0x2a96/0x3400 net/ipv6/udp.c:1343
  inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764
  sock_sendmsg_nosec net/socket.c:630 [inline]
  sock_sendmsg+0xca/0x110 net/socket.c:640
  ___sys_sendmsg+0x320/0x8b0 net/socket.c:2046
  __sys_sendmmsg+0x1ee/0x620 net/socket.c:2136
  SYSC_sendmmsg net/socket.c:2167 [inline]
  SyS_sendmmsg+0x35/0x60 net/socket.c:2162
  do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4404c9
RSP: 002b:00007ffdce35f948 EFLAGS: 00000217 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004404c9
RDX: 0000000000000003 RSI: 0000000020001f00 RDI: 0000000000000003
RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 0000000020000080 R11: 0000000000000217 R12: 0000000000401df0
R13: 0000000000401e80 R14: 0000000000000000 R15: 0000000000000000
Code: ff e8 1d 5e b9 fc e9 15 e9 ff ff e8 13 5e b9 fc e9 44 e8 ff ff e8 29
5e b9 fc e9 c0 e6 ff ff e8 3f f3 80 fc 0f 0b e8 38 f3 80 fc <0f> 0b 49 8d
87 80 00 00 00 4d 8d 87 84 00 00 00 48 89 85 20 fe
RIP: __skb_pull include/linux/skbuff.h:2073 [inline] RSP: ffff8801bc18f0f0
RIP: __ip6_make_skb+0x1ac8/0x2190 net/ipv6/ip6_output.c:1636 RSP:
ffff8801bc18f0f0

As stated by RFC 7112 section 5:

   When a host fragments an IPv6 datagram, it MUST include the entire
   IPv6 Header Chain in the First Fragment.

So this patch addresses the issue dropping datagrams with excessive
extheader length. It also updates the error path to report to the
calling socket nonnegative pmtu values.

The issue apparently predates git history.

v1 -> v2: cleanup error path, as per Eric's suggestion

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot+91e6f9932ff122fa4410@syzkaller.appspotmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-12 12:32:23 +02:00
..
6lowpan License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
9p 9p/trans_virtio: discard zero-length reply 2018-02-22 15:42:30 +01:00
802 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
8021q 8021q: fix a memory leak for VLAN 0 device 2018-01-17 09:45:20 +01:00
appletalk License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
atm License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ax25 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
batman-adv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-08-09 16:28:45 -07:00
bluetooth Bluetooth: Fix missing encryption refresh on Security Request 2018-04-08 14:26:30 +02:00
bpf
bridge netfilter: bridge: ebt_among: add more missing match size checks 2018-04-08 14:26:29 +02:00
caif License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
can can: af_can: canfd_rcv(): replace WARN_ONCE by pr_warn_once 2018-01-23 19:58:17 +01:00
ceph libceph: don't WARN() if user tries to add invalid key 2017-11-30 08:40:45 +00:00
core skbuff: Fix not waking applications when errors are enqueued 2018-03-31 18:10:42 +02:00
dcb rtnetlink: make rtnl_register accept a flags parameter 2017-08-09 16:57:38 -07:00
dccp dccp: check sk for closed state in dccp_sendmsg() 2018-03-31 18:10:40 +02:00
decnet dn_getsockoptdecnet: move nf_{get/set}sockopt outside sock lock 2018-02-25 11:07:52 +01:00
dns_resolver KEYS: Fix race between updating and finding a negative key 2017-10-18 09:12:40 +01:00
dsa net: dsa: return after vlan prepare phase 2017-11-11 15:45:09 +09:00
ethernet
hsr net/hsr: Check skb_put_padto() return value 2017-08-22 13:40:23 -07:00
ieee802154 ieee802154: 6lowpan: fix possible NULL deref in lowpan_device_event() 2018-03-31 18:10:40 +02:00
ife MAINTAINERS: Update Yotam's E-mail 2017-11-01 12:19:03 +09:00
ipv4 arp: fix arp_filter on l3slave devices 2018-04-12 12:32:22 +02:00
ipv6 ipv6: the entire IPv6 header chain must fit the first fragment 2018-04-12 12:32:23 +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: lock lower socket in kcm_attach 2018-03-31 18:10:40 +02:00
key af_key: fix buffer overread in parse_exthdrs() 2018-01-23 19:58:12 +01:00
l2tp l2tp: fix missing print session offset info 2018-04-12 12:32:12 +02:00
l3mdev
lapb net, lapb: convert lapb_cb.refcnt from atomic_t to refcount_t 2017-07-04 22:35:16 +01:00
llc License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mac80211 mac80211: Fix setting TX power on monitor interfaces 2018-04-12 12:32:15 +02:00
mac802154 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mpls mpls, nospec: Sanitize array index in mpls_label_ok() 2018-02-22 15:42:28 +01:00
ncsi net/ncsi: Fix length of GVI response packet 2017-10-21 01:56:38 +01:00
netfilter netfilter: x_tables: add and use xt_check_proc_name 2018-04-08 14:26:29 +02:00
netlabel License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
netlink netlink: avoid a double skb free in genlmsg_mcast() 2018-03-31 18:10:41 +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 device-allocation error return 2017-11-30 08:40:55 +00:00
nsh nsh: add GSO support 2017-08-29 15:16:52 -07:00
openvswitch openvswitch: fix the incorrect flow action alloc size 2018-02-03 17:39:03 +01:00
packet net/packet: fix a race in packet_bind() and packet_notifier() 2017-12-17 15:07:56 +01:00
phonet License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
psample MAINTAINERS: Update Yotam's E-mail 2017-11-01 12:19:03 +09:00
qrtr qrtr: Move to postcore_initcall 2017-11-08 14:32:18 +09:00
rds rds; Reset rs->rs_bound_addr in rds_add_bound() failure path 2018-04-12 12:32:12 +02:00
rfkill
rose
rxrpc rxrpc: Fix send in rxrpc_send_data_packet() 2018-03-08 22:41:12 -08:00
sched sch_netem: fix skb leak in netem_enqueue() 2018-03-31 18:10:40 +02:00
sctp sctp: fix dst refcnt leak in sctp_v6_get_dst() 2018-03-08 22:41:15 -08:00
smc net/smc: fix NULL pointer dereference on sock_create_kern() error path 2018-03-15 10:54:28 +01:00
strparser strparser: Use delayed work instead of timer for msg timeout 2017-10-25 10:37:11 +09:00
sunrpc xprtrdma: Fix BUG after a device removal 2018-02-22 15:42:29 +01:00
switchdev net: switchdev: Remove bridge bypass support from switchdev 2017-08-07 14:48:48 -07:00
tipc tipc: fix tipc_mon_delete() oops in tipc_enable_bearer() error path 2018-03-03 10:24:30 +01:00
tls tls: reset crypto_info when do_tls_setsockopt_tx fails 2018-01-31 14:03:48 +01:00
unix License cleanup: add SPDX license identifiers to some files 2017-11-02 10:04:46 -07:00
vmw_vsock VSOCK: fix outdated sk_state value in hvs_release() 2018-02-25 11:07:59 +01:00
wimax License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
wireless nl80211: Check for the required netlink attribute presence 2018-03-03 10:24:34 +01:00
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: Refuse to insert 32 bit userspace socket policies on 64 bit systems 2018-04-08 14:26:29 +02:00
compat.c net: compat: assert the size of cmsg copied in is as expected 2017-09-20 15:36:18 -07:00
Kconfig net: Remove CONFIG_NETFILTER_DEBUG and _ASSERT() macros. 2017-09-04 13:25:20 +02:00
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 kmemcheck: remove annotations 2018-02-22 15:42:23 +01:00
sysctl_net.c