linux/net/ipv6
David Lebrun af3b5158b8 ipv6: sr: fix BUG due to headroom too small after SRH push
When a locally generated packet receives an SRH with two or more segments,
the remaining headroom is too small to push an ethernet header. This patch
ensures that the headroom is large enough after SRH push.

The BUG generated the following trace.

[  192.950285] skbuff: skb_under_panic: text:ffffffff81809675 len:198 put:14 head:ffff88006f306400 data:ffff88006f3063fa tail:0xc0 end:0x2c0 dev:A-1
[  192.952456] ------------[ cut here ]------------
[  192.953218] kernel BUG at net/core/skbuff.c:105!
[  192.953411] invalid opcode: 0000 [#1] PREEMPT SMP
[  192.953411] Modules linked in:
[  192.953411] CPU: 5 PID: 3433 Comm: ping6 Not tainted 4.11.0-rc3+ #237
[  192.953411] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014
[  192.953411] task: ffff88007c2d42c0 task.stack: ffffc90000ef4000
[  192.953411] RIP: 0010:skb_panic+0x61/0x70
[  192.953411] RSP: 0018:ffffc90000ef7900 EFLAGS: 00010286
[  192.953411] RAX: 0000000000000085 RBX: 00000000000086dd RCX: 0000000000000201
[  192.953411] RDX: 0000000080000201 RSI: ffffffff81d104c5 RDI: 00000000ffffffff
[  192.953411] RBP: ffffc90000ef7920 R08: 0000000000000001 R09: 0000000000000000
[  192.953411] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[  192.953411] R13: ffff88007c5a4000 R14: ffff88007b363d80 R15: 00000000000000b8
[  192.953411] FS:  00007f94b558b700(0000) GS:ffff88007fd40000(0000) knlGS:0000000000000000
[  192.953411] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  192.953411] CR2: 00007fff5ecd5080 CR3: 0000000074141000 CR4: 00000000001406e0
[  192.953411] Call Trace:
[  192.953411]  skb_push+0x3b/0x40
[  192.953411]  eth_header+0x25/0xc0
[  192.953411]  neigh_resolve_output+0x168/0x230
[  192.953411]  ? ip6_finish_output2+0x242/0x8f0
[  192.953411]  ip6_finish_output2+0x242/0x8f0
[  192.953411]  ? ip6_finish_output2+0x76/0x8f0
[  192.953411]  ip6_finish_output+0xa8/0x1d0
[  192.953411]  ip6_output+0x64/0x2d0
[  192.953411]  ? ip6_output+0x73/0x2d0
[  192.953411]  ? ip6_dst_check+0xb5/0xc0
[  192.953411]  ? dst_cache_per_cpu_get.isra.2+0x40/0x80
[  192.953411]  seg6_output+0xb0/0x220
[  192.953411]  lwtunnel_output+0xcf/0x210
[  192.953411]  ? lwtunnel_output+0x59/0x210
[  192.953411]  ip6_local_out+0x38/0x70
[  192.953411]  ip6_send_skb+0x2a/0xb0
[  192.953411]  ip6_push_pending_frames+0x48/0x50
[  192.953411]  rawv6_sendmsg+0xa39/0xf10
[  192.953411]  ? __lock_acquire+0x489/0x890
[  192.953411]  ? __mutex_lock+0x1fc/0x970
[  192.953411]  ? __lock_acquire+0x489/0x890
[  192.953411]  ? __mutex_lock+0x1fc/0x970
[  192.953411]  ? tty_ioctl+0x283/0xec0
[  192.953411]  inet_sendmsg+0x45/0x1d0
[  192.953411]  ? _copy_from_user+0x54/0x80
[  192.953411]  sock_sendmsg+0x33/0x40
[  192.953411]  SYSC_sendto+0xef/0x170
[  192.953411]  ? entry_SYSCALL_64_fastpath+0x5/0xc2
[  192.953411]  ? trace_hardirqs_on_caller+0x12b/0x1b0
[  192.953411]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[  192.953411]  SyS_sendto+0x9/0x10
[  192.953411]  entry_SYSCALL_64_fastpath+0x1f/0xc2
[  192.953411] RIP: 0033:0x7f94b453db33
[  192.953411] RSP: 002b:00007fff5ecd0578 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[  192.953411] RAX: ffffffffffffffda RBX: 00007fff5ecd16e0 RCX: 00007f94b453db33
[  192.953411] RDX: 0000000000000040 RSI: 000055a78352e9c0 RDI: 0000000000000003
[  192.953411] RBP: 00007fff5ecd1690 R08: 000055a78352c940 R09: 000000000000001c
[  192.953411] R10: 0000000000000000 R11: 0000000000000246 R12: 000055a783321e10
[  192.953411] R13: 000055a7839890c0 R14: 0000000000000004 R15: 0000000000000000
[  192.953411] Code: 00 00 48 89 44 24 10 8b 87 c4 00 00 00 48 89 44 24 08 48 8b 87 d8 00 00 00 48 c7 c7 90 58 d2 81 48 89 04 24 31 c0 e8 4f 70 9a ff <0f> 0b 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 48 8b 97 d8 00 00
[  192.953411] RIP: skb_panic+0x61/0x70 RSP: ffffc90000ef7900
[  193.000186] ---[ end trace bd0b89fabdf2f92c ]---
[  193.000951] Kernel panic - not syncing: Fatal exception in interrupt
[  193.001137] Kernel Offset: disabled
[  193.001169] ---[ end Kernel panic - not syncing: Fatal exception in interrupt

Fixes: 19d5a26f5e ("ipv6: sr: expand skb head only if necessary")
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-17 15:33:53 -04:00
..
ila netlink: pass extended ACK struct to parsing functions 2017-04-13 13:58:22 -04:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-03-23 16:41:27 -07:00
addrconf_core.c ipv6: change ipv6_stub_impl.ipv6_dst_lookup to take net argument 2015-07-31 15:21:30 -07:00
addrconf.c Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next 2017-04-17 15:00:57 -04:00
addrlabel.c netlink: pass extended ACK struct to parsing functions 2017-04-13 13:58:22 -04:00
af_inet6.c ipv6: add support for NETDEV_RESEND_IGMP event 2017-03-28 22:02:21 -07:00
ah6.c IPsec: do not ignore crypto err in ah6 input 2017-01-16 12:57:48 +01:00
anycast.c
calipso.c calipso: fix resource leak on calipso_genopt failure 2016-08-13 14:56:17 -07:00
datagram.c ipv6: Handle IPv4-mapped src to in6addr_any dst. 2017-02-14 12:13:51 -05:00
esp6_offload.c esp: Add a software GRO codepath 2017-02-15 11:04:11 +01:00
esp6.c esp: Introduce a helper to setup the trailer 2017-01-17 10:23:08 +01:00
exthdrs_core.c ipv6: constify the skb pointer of ipv6_find_tlv(). 2016-06-27 15:06:15 -04:00
exthdrs_offload.c ipv6: fix exthdrs offload registration in out_rt path 2015-09-02 15:31:00 -07:00
exthdrs.c ipv6: sr: remove cleanup flag and fix HMAC computation 2017-02-03 11:05:23 -05:00
fib6_rules.c net: flow: Add l3mdev flow update 2016-09-10 23:12:51 -07:00
fou6.c fou: add Kconfig options for IPv6 support 2016-05-29 22:24:21 -07:00
icmp.c net: for rate-limited ICMP replies save one atomic operation 2017-01-09 15:49:12 -05:00
inet6_connection_sock.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-28 10:33:06 -05:00
inet6_hashtables.c inet: collapse ipv4/v6 rcv_saddr_equal functions into one 2017-01-18 13:04:28 -05:00
ip6_checksum.c ipv6: fix checksum annotation in udp6_csum_init 2016-06-14 15:26:42 -04:00
ip6_fib.c ipv6: make ECMP route replacement less greedy 2017-03-13 12:16:17 -07:00
ip6_flowlabel.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
ip6_gre.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-02-07 16:29:30 -05:00
ip6_icmp.c ipv6: icmp: add a force_saddr param to icmp6_send() 2016-06-18 22:11:38 -07:00
ip6_input.c net: Add sysctl to toggle early demux for tcp and udp 2017-03-24 13:17:07 -07:00
ip6_offload.c net/tunnel: set inner protocol in network gro hooks 2017-03-09 13:19:52 -08:00
ip6_offload.h udp: Add GRO functions to UDP socket 2016-04-07 16:53:29 -04:00
ip6_output.c ipv6: avoid write to a possibly cloned skb 2017-03-13 12:53:35 -07:00
ip6_tunnel.c ipv6: pointer math error in ip6_tnl_parse_tlv_enc_lim() 2017-02-01 12:27:33 -05:00
ip6_udp_tunnel.c ip6_udp_tunnel: remove unused IPCB related codes 2016-11-02 15:18:36 -04:00
ip6_vti.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec 2017-03-07 15:00:37 -08:00
ip6mr.c net: ipv6: Refactor inet6_netconf_notify_devconf to take event 2017-03-28 22:32:42 -07:00
ipcomp6.c net: inet: Support UID-based routing in IP protocols. 2016-11-04 14:45:23 -04:00
ipv6_sockglue.c net: Allow IP_MULTICAST_IF to set index to L3 slave 2016-12-30 15:24:47 -05:00
Kconfig ipv6: sr: select DST_CACHE by default 2017-03-27 16:05:06 -07:00
Makefile esp: Add a software GRO codepath 2017-02-15 11:04:11 +01:00
mcast_snoop.c net: fix wrong skb_get() usage / crash in IGMP/MLD parsing code 2015-08-13 17:08:39 -07:00
mcast.c ipv6: add support for NETDEV_RESEND_IGMP event 2017-03-28 22:02:21 -07:00
mip6.c ktime: Get rid of ktime_equal() 2016-12-25 17:21:23 +01:00
ndisc.c net: ipv6: send unsolicited NA on admin up 2017-04-17 12:44:55 -04:00
netfilter.c net: inet: Support UID-based routing in IP protocols. 2016-11-04 14:45:23 -04:00
output_core.c ipv6: Set skb->protocol properly for local output 2016-12-02 12:34:22 -05:00
ping.c ipv6: remove unnecessary inet6_sk check 2016-12-29 12:05:49 -05:00
proc.c proc: Reduce cache miss in snmp6_seq_show 2016-09-30 01:50:44 -04:00
protocol.c net: Add sysctl to toggle early demux for tcp and udp 2017-03-24 13:17:07 -07:00
raw.c net: use dst_confirm_neigh for UDP, RAW, ICMP, L2TP 2017-02-07 13:07:47 -05:00
reassembly.c ipv6: on reassembly, record frag_max_size 2016-11-03 15:41:11 -04:00
route.c netlink: pass extended ACK struct to parsing functions 2017-04-13 13:58:22 -04:00
seg6_hmac.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-02-07 16:29:30 -05:00
seg6_iptunnel.c ipv6: sr: fix BUG due to headroom too small after SRH push 2017-04-17 15:33:53 -04:00
seg6.c ipv6: seg6_genl_set_tunsrc() must check kmemdup() return value 2017-01-20 11:07:48 -05:00
sit.c sit: fix a double free on error path 2017-02-08 13:12:22 -05:00
syncookies.c syncookies: use SipHash in place of SHA1 2017-01-09 13:58:57 -05:00
sysctl_net_ipv6.c calipso: Add a label cache. 2016-06-27 15:06:17 -04:00
tcp_ipv6.c tcp: Record Rx hash and NAPI ID in tcp_child_process 2017-03-24 20:49:30 -07:00
tcpv6_offload.c
tunnel6.c ipv6: fix tunnel error handling 2015-11-03 10:52:13 -05:00
udp_impl.h udplite: call proper backlog handlers 2016-11-24 15:32:14 -05:00
udp_offload.c gso: Remove arbitrary checks for unsupported GSO 2016-05-20 18:03:15 -04:00
udp.c net: Add sysctl to toggle early demux for tcp and udp 2017-03-24 13:17:07 -07:00
udplite.c udplite: call proper backlog handlers 2016-11-24 15:32:14 -05:00
xfrm6_input.c esp: Add a software GRO codepath 2017-02-15 11:04:11 +01:00
xfrm6_mode_beet.c
xfrm6_mode_ro.c
xfrm6_mode_transport.c esp: Add a software GRO codepath 2017-02-15 11:04:11 +01:00
xfrm6_mode_tunnel.c ipv6: update skb->csum when CE mark is propagated 2016-01-15 15:07:23 -05:00
xfrm6_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-10-24 06:54:12 -07:00
xfrm6_policy.c xfrm: policy: make policy backend const 2017-02-09 10:22:19 +01:00
xfrm6_protocol.c xfrm: input: constify xfrm_input_afinfo 2017-02-09 10:22:17 +01:00
xfrm6_state.c
xfrm6_tunnel.c netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00