linux/net
Petr Machata 5691484df9 net: ip6_gre: Fix headroom request in ip6erspan_tunnel_xmit()
dev->needed_headroom is not primed until ip6_tnl_xmit(), so it starts
out zero. Thus the call to skb_cow_head() fails to actually make sure
there's enough headroom to push the ERSPAN headers to. That can lead to
the panic cited below. (Reproducer below that).

Fix by requesting either needed_headroom if already primed, or just the
bare minimum needed for the header otherwise.

[  190.703567] kernel BUG at net/core/skbuff.c:104!
[  190.708384] invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
[  190.714007] Modules linked in: act_mirred cls_matchall ip6_gre ip6_tunnel tunnel6 gre sch_ingress vrf veth x86_pkg_temp_thermal mlx_platform nfsd e1000e leds_mlxcpld
[  190.728975] CPU: 1 PID: 959 Comm: kworker/1:2 Not tainted 4.17.0-rc4-net_master-custom-139 #10
[  190.737647] Hardware name: Mellanox Technologies Ltd. "MSN2410-CB2F"/"SA000874", BIOS 4.6.5 03/08/2016
[  190.747006] Workqueue: ipv6_addrconf addrconf_dad_work
[  190.752222] RIP: 0010:skb_panic+0xc3/0x100
[  190.756358] RSP: 0018:ffff8801d54072f0 EFLAGS: 00010282
[  190.761629] RAX: 0000000000000085 RBX: ffff8801c1a8ecc0 RCX: 0000000000000000
[  190.768830] RDX: 0000000000000085 RSI: dffffc0000000000 RDI: ffffed003aa80e54
[  190.776025] RBP: ffff8801bd1ec5a0 R08: ffffed003aabce19 R09: ffffed003aabce19
[  190.783226] R10: 0000000000000001 R11: ffffed003aabce18 R12: ffff8801bf695dbe
[  190.790418] R13: 0000000000000084 R14: 00000000000006c0 R15: ffff8801bf695dc8
[  190.797621] FS:  0000000000000000(0000) GS:ffff8801d5400000(0000) knlGS:0000000000000000
[  190.805786] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  190.811582] CR2: 000055fa929aced0 CR3: 0000000003228004 CR4: 00000000001606e0
[  190.818790] Call Trace:
[  190.821264]  <IRQ>
[  190.823314]  ? ip6erspan_tunnel_xmit+0x5e4/0x1982 [ip6_gre]
[  190.828940]  ? ip6erspan_tunnel_xmit+0x5e4/0x1982 [ip6_gre]
[  190.834562]  skb_push+0x78/0x90
[  190.837749]  ip6erspan_tunnel_xmit+0x5e4/0x1982 [ip6_gre]
[  190.843219]  ? ip6gre_tunnel_ioctl+0xd90/0xd90 [ip6_gre]
[  190.848577]  ? debug_check_no_locks_freed+0x210/0x210
[  190.853679]  ? debug_check_no_locks_freed+0x210/0x210
[  190.858783]  ? print_irqtrace_events+0x120/0x120
[  190.863451]  ? sched_clock_cpu+0x18/0x210
[  190.867496]  ? cyc2ns_read_end+0x10/0x10
[  190.871474]  ? skb_network_protocol+0x76/0x200
[  190.875977]  dev_hard_start_xmit+0x137/0x770
[  190.880317]  ? do_raw_spin_trylock+0x6d/0xa0
[  190.884624]  sch_direct_xmit+0x2ef/0x5d0
[  190.888589]  ? pfifo_fast_dequeue+0x3fa/0x670
[  190.892994]  ? pfifo_fast_change_tx_queue_len+0x810/0x810
[  190.898455]  ? __lock_is_held+0xa0/0x160
[  190.902422]  __qdisc_run+0x39e/0xfc0
[  190.906041]  ? _raw_spin_unlock+0x29/0x40
[  190.910090]  ? pfifo_fast_enqueue+0x24b/0x3e0
[  190.914501]  ? sch_direct_xmit+0x5d0/0x5d0
[  190.918658]  ? pfifo_fast_dequeue+0x670/0x670
[  190.923047]  ? __dev_queue_xmit+0x172/0x1770
[  190.927365]  ? preempt_count_sub+0xf/0xd0
[  190.931421]  __dev_queue_xmit+0x410/0x1770
[  190.935553]  ? ___slab_alloc+0x605/0x930
[  190.939524]  ? print_irqtrace_events+0x120/0x120
[  190.944186]  ? memcpy+0x34/0x50
[  190.947364]  ? netdev_pick_tx+0x1c0/0x1c0
[  190.951428]  ? __skb_clone+0x2fd/0x3d0
[  190.955218]  ? __copy_skb_header+0x270/0x270
[  190.959537]  ? rcu_read_lock_sched_held+0x93/0xa0
[  190.964282]  ? kmem_cache_alloc+0x344/0x4d0
[  190.968520]  ? cyc2ns_read_end+0x10/0x10
[  190.972495]  ? skb_clone+0x123/0x230
[  190.976112]  ? skb_split+0x820/0x820
[  190.979747]  ? tcf_mirred+0x554/0x930 [act_mirred]
[  190.984582]  tcf_mirred+0x554/0x930 [act_mirred]
[  190.989252]  ? tcf_mirred_act_wants_ingress.part.2+0x10/0x10 [act_mirred]
[  190.996109]  ? __lock_acquire+0x706/0x26e0
[  191.000239]  ? sched_clock_cpu+0x18/0x210
[  191.004294]  tcf_action_exec+0xcf/0x2a0
[  191.008179]  tcf_classify+0xfa/0x340
[  191.011794]  __netif_receive_skb_core+0x8e1/0x1c60
[  191.016630]  ? debug_check_no_locks_freed+0x210/0x210
[  191.021732]  ? nf_ingress+0x500/0x500
[  191.025458]  ? process_backlog+0x347/0x4b0
[  191.029619]  ? print_irqtrace_events+0x120/0x120
[  191.034302]  ? lock_acquire+0xd8/0x320
[  191.038089]  ? process_backlog+0x1b6/0x4b0
[  191.042246]  ? process_backlog+0xc2/0x4b0
[  191.046303]  process_backlog+0xc2/0x4b0
[  191.050189]  net_rx_action+0x5cc/0x980
[  191.053991]  ? napi_complete_done+0x2c0/0x2c0
[  191.058386]  ? mark_lock+0x13d/0xb40
[  191.062001]  ? clockevents_program_event+0x6b/0x1d0
[  191.066922]  ? print_irqtrace_events+0x120/0x120
[  191.071593]  ? __lock_is_held+0xa0/0x160
[  191.075566]  __do_softirq+0x1d4/0x9d2
[  191.079282]  ? ip6_finish_output2+0x524/0x1460
[  191.083771]  do_softirq_own_stack+0x2a/0x40
[  191.087994]  </IRQ>
[  191.090130]  do_softirq.part.13+0x38/0x40
[  191.094178]  __local_bh_enable_ip+0x135/0x190
[  191.098591]  ip6_finish_output2+0x54d/0x1460
[  191.102916]  ? ip6_forward_finish+0x2f0/0x2f0
[  191.107314]  ? ip6_mtu+0x3c/0x2c0
[  191.110674]  ? ip6_finish_output+0x2f8/0x650
[  191.114992]  ? ip6_output+0x12a/0x500
[  191.118696]  ip6_output+0x12a/0x500
[  191.122223]  ? ip6_route_dev_notify+0x5b0/0x5b0
[  191.126807]  ? ip6_finish_output+0x650/0x650
[  191.131120]  ? ip6_fragment+0x1a60/0x1a60
[  191.135182]  ? icmp6_dst_alloc+0x26e/0x470
[  191.139317]  mld_sendpack+0x672/0x830
[  191.143021]  ? igmp6_mcf_seq_next+0x2f0/0x2f0
[  191.147429]  ? __local_bh_enable_ip+0x77/0x190
[  191.151913]  ipv6_mc_dad_complete+0x47/0x90
[  191.156144]  addrconf_dad_completed+0x561/0x720
[  191.160731]  ? addrconf_rs_timer+0x3a0/0x3a0
[  191.165036]  ? mark_held_locks+0xc9/0x140
[  191.169095]  ? __local_bh_enable_ip+0x77/0x190
[  191.173570]  ? addrconf_dad_work+0x50d/0xa20
[  191.177886]  ? addrconf_dad_work+0x529/0xa20
[  191.182194]  addrconf_dad_work+0x529/0xa20
[  191.186342]  ? addrconf_dad_completed+0x720/0x720
[  191.191088]  ? __lock_is_held+0xa0/0x160
[  191.195059]  ? process_one_work+0x45d/0xe20
[  191.199302]  ? process_one_work+0x51e/0xe20
[  191.203531]  ? rcu_read_lock_sched_held+0x93/0xa0
[  191.208279]  process_one_work+0x51e/0xe20
[  191.212340]  ? pwq_dec_nr_in_flight+0x200/0x200
[  191.216912]  ? get_lock_stats+0x4b/0xf0
[  191.220788]  ? preempt_count_sub+0xf/0xd0
[  191.224844]  ? worker_thread+0x219/0x860
[  191.228823]  ? do_raw_spin_trylock+0x6d/0xa0
[  191.233142]  worker_thread+0xeb/0x860
[  191.236848]  ? process_one_work+0xe20/0xe20
[  191.241095]  kthread+0x206/0x300
[  191.244352]  ? process_one_work+0xe20/0xe20
[  191.248587]  ? kthread_stop+0x570/0x570
[  191.252459]  ret_from_fork+0x3a/0x50
[  191.256082] Code: 14 3e ff 8b 4b 78 55 4d 89 f9 41 56 41 55 48 c7 c7 a0 cf db 82 41 54 44 8b 44 24 2c 48 8b 54 24 30 48 8b 74 24 20 e8 16 94 13 ff <0f> 0b 48 c7 c7 60 8e 1f 85 48 83 c4 20 e8 55 ef a6 ff 89 74 24
[  191.275327] RIP: skb_panic+0xc3/0x100 RSP: ffff8801d54072f0
[  191.281024] ---[ end trace 7ea51094e099e006 ]---
[  191.285724] Kernel panic - not syncing: Fatal exception in interrupt
[  191.292168] Kernel Offset: disabled
[  191.295697] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

Reproducer:

	ip link add h1 type veth peer name swp1
	ip link add h3 type veth peer name swp3

	ip link set dev h1 up
	ip address add 192.0.2.1/28 dev h1

	ip link add dev vh3 type vrf table 20
	ip link set dev h3 master vh3
	ip link set dev vh3 up
	ip link set dev h3 up

	ip link set dev swp3 up
	ip address add dev swp3 2001:db8:2::1/64

	ip link set dev swp1 up
	tc qdisc add dev swp1 clsact

	ip link add name gt6 type ip6erspan \
		local 2001:db8:2::1 remote 2001:db8:2::2 oseq okey 123
	ip link set dev gt6 up

	sleep 1

	tc filter add dev swp1 ingress pref 1000 matchall skip_hw \
		action mirred egress mirror dev gt6
	ping -I h1 192.0.2.2

Fixes: e41c7c68ea ("ip6erspan: make sure enough headroom at xmit.")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-17 16:50:06 -04:00
..
6lowpan
9p net/9p: fix spelling mistake: "suspsend" -> "suspend" 2018-05-10 15:23:50 -04:00
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: atm: Fix potential Spectre v1 2018-05-04 12:52:47 -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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2018-05-13 20:28:47 -04:00
caif net: caif: fix spelling mistake "UKNOWN" -> "UNKNOWN" 2018-04-19 13:37:10 -04:00
can net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
ceph libceph: add osd_req_op_extent_osd_data_bvecs() 2018-05-10 10:15:05 +02:00
core ethtool: fix a potential missing-check bug 2018-05-01 14:18:47 -04:00
dcb
dccp dccp: fix tasklet usage 2018-05-03 15:14:57 -04:00
decnet net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
dns_resolver KEYS: DNS: limit the length of option strings 2018-04-17 15:17:41 -04:00
dsa net: dsa: Discard frames from unused ports 2018-04-08 10:34:49 -04:00
ethernet
hsr
ieee802154 net: ieee802154: 6lowpan: fix frag reassembly 2018-04-23 20:56:24 +02:00
ife net: sched: ife: check on metadata length 2018-04-22 21:12:00 -04:00
ipv4 erspan: fix invalid erspan version. 2018-05-17 15:48:49 -04:00
ipv6 net: ip6_gre: Fix headroom request in ip6erspan_tunnel_xmit() 2018-05-17 16:50:06 -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 af_key: Always verify length of provided sadb_key 2018-04-09 07:06:38 +02:00
l2tp l2tp: check sockaddr length in pppol2tp_connect() 2018-04-23 21:10:43 -04:00
l3mdev
lapb
llc llc: better deal with too small mtu 2018-05-08 00:11:40 -04:00
mac80211 mac80211: use timeout from the AddBA response instead of the request 2018-05-07 20:35:15 +02:00
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 netfilter: nf_tables: fix memory leak on error exit return 2018-05-14 00:21:59 +02:00
netlabel netlabel: If PF_INET6, check sk_buff ip header version 2018-02-14 14:01:41 -05:00
netlink net/netlink: make sure the headers line up actual value output 2018-05-04 13:00:57 -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 nsh: fix infinite loop 2018-05-04 12:54:38 -04:00
openvswitch openvswitch: Don't swap table in nlattr_set() after OVS_ATTR_NESTED is found 2018-05-04 12:51:02 -04:00
packet packet: in packet_snd start writing at link layer allocation 2018-05-13 20:19:27 -04:00
phonet net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
psample
qrtr net: qrtr: add MODULE_ALIAS_NETPROTO macro 2018-04-17 09:58:00 -04:00
rds rds: do not leak kernel memory to user land 2018-05-03 11:26:14 -04:00
rfkill rfkill: gpio: fix memory leak in probe error path 2018-05-07 15:01:40 +02:00
rose net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
rxrpc rxrpc: Trace UDP transmission failure 2018-05-10 23:26:01 +01:00
sched net/sched: fix refcnt leak in the error path of tcf_vlan_init() 2018-05-16 14:41:44 -04:00
sctp sctp: remove sctp_chunk_put from fail_mark err path in sctp_ulpevent_make_rcvmsg 2018-05-10 17:48:36 -04:00
smc net/smc: check for missing nlattrs in SMC_PNETID messages 2018-05-14 16:40:45 -04:00
strparser strparser: Do not call mod_delayed_work with a timeout of LONG_MAX 2018-04-22 21:09:16 -04:00
sunrpc NFS client fixes for Linux 4.17-rc4 2018-05-11 13:56:43 -07:00
switchdev
tipc tipc: fix one byte leak in tipc_sk_set_orig_addr() 2018-05-10 17:28:39 -04:00
tls tls: don't use stack memory in a scatterlist 2018-05-17 14:49:38 -04:00
unix af_unix: remove redundant lockdep class 2018-04-04 11:13:40 -04:00
vmw_vsock VSOCK: make af_vsock.ko removable again 2018-04-17 09:44:30 -04:00
wimax
wireless nl80211: Free connkeys on external authentication failure 2018-04-20 09:58:03 +02:00
x25 net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
xfrm xfrm: Fix warning in xfrm6_tunnel_net_exit. 2018-04-16 07:50:09 +02:00
compat.c net: support compat 64-bit time in {s,g}etsockopt 2018-04-27 19:46:06 -04:00
Kconfig Staging/IIO patches for 4.16-rc1 2018-02-01 09:51:57 -08:00
Makefile
socket.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2018-04-05 11:56:35 -07:00
sysctl_net.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00