linux-toradex.git/net/ipv6/sit.c, branch v4.9.65

sit: fix a double free on error path

2017-02-18T14:11:43+00:00

[ Upstream commit d7426c69a1942b2b9b709bf66b944ff09f561484 ]

Dmitry reported a double free in sit_init_net():

  kernel BUG at mm/percpu.c:689!
  invalid opcode: 0000 [#1] SMP KASAN
  Dumping ftrace buffer:
     (ftrace buffer empty)
  Modules linked in:
  CPU: 0 PID: 15692 Comm: syz-executor1 Not tainted 4.10.0-rc6-next-20170206 #1
  Hardware name: Google Google Compute Engine/Google Compute Engine,
  BIOS Google 01/01/2011
  task: ffff8801c9cc27c0 task.stack: ffff88017d1d8000
  RIP: 0010:pcpu_free_area+0x68b/0x810 mm/percpu.c:689
  RSP: 0018:ffff88017d1df488 EFLAGS: 00010046
  RAX: 0000000000010000 RBX: 00000000000007c0 RCX: ffffc90002829000
  RDX: 0000000000010000 RSI: ffffffff81940efb RDI: ffff8801db841d94
  RBP: ffff88017d1df590 R08: dffffc0000000000 R09: 1ffffffff0bb3bdd
  R10: dffffc0000000000 R11: 00000000000135dd R12: ffff8801db841d80
  R13: 0000000000038e40 R14: 00000000000007c0 R15: 00000000000007c0
  FS:  00007f6ea608f700(0000) GS:ffff8801dbe00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 000000002000aff8 CR3: 00000001c8d44000 CR4: 00000000001426f0
  DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
  Call Trace:
   free_percpu+0x212/0x520 mm/percpu.c:1264
   ipip6_dev_free+0x43/0x60 net/ipv6/sit.c:1335
   sit_init_net+0x3cb/0xa10 net/ipv6/sit.c:1831
   ops_init+0x10a/0x530 net/core/net_namespace.c:115
   setup_net+0x2ed/0x690 net/core/net_namespace.c:291
   copy_net_ns+0x26c/0x530 net/core/net_namespace.c:396
   create_new_namespaces+0x409/0x860 kernel/nsproxy.c:106
   unshare_nsproxy_namespaces+0xae/0x1e0 kernel/nsproxy.c:205
   SYSC_unshare kernel/fork.c:2281 [inline]
   SyS_unshare+0x64e/0xfc0 kernel/fork.c:2231
   entry_SYSCALL_64_fastpath+0x1f/0xc2

This is because when tunnel->dst_cache init fails, we free dev->tstats
once in ipip6_tunnel_init() and twice in sit_init_net(). This looks
redundant but its ndo_uinit() does not seem enough to clean up everything
here. So avoid this by setting dev->tstats to NULL after the first free,
at least for -net.

Reported-by: Dmitry Vyukov 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sit: make function ipip6_valid_ip_proto() static

2016-08-13T04:52:18+00:00

Fixes the following sparse warning:

net/ipv6/sit.c:1129:6: warning:
 symbol 'ipip6_valid_ip_proto' was not declared. Should it be static?

Signed-off-by: Wei Yongjun 
Signed-off-by: David S. Miller

net: resolve symbol conflicts with generic hashtable.h

2016-08-11T00:18:52+00:00

This is a preparatory patch for converting qdisc linked list into a
hashtable. As we'll need to include hashtable.h in netdevice.h, we first
have to make sure that this will not introduce symbol conflicts for any of
the netdevice.h users.

Reviewed-by: Cong Wang 
Signed-off-by: Jiri Kosina 
Signed-off-by: David S. Miller

sit: support MPLS over IPv4

2016-07-09T21:45:56+00:00

Extend the SIT driver to support MPLS over IPv4. This implementation
extends existing support for IPv6 over IPv4 and IPv4 over IPv4.

Signed-off-by: Simon Horman 
Reviewed-by: Dinan Gunawardena 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-06-30T09:03:36+00:00

Several cases of overlapping changes, except the packet scheduler
conflicts which deal with the addition of the free list parameter
to qdisc_enqueue().

Signed-off-by: David S. Miller

ipv6: RFC 4884 partial support for SIT/GRE tunnels

2016-06-19T05:11:39+00:00

When receiving an ICMPv4 message containing extensions as
defined in RFC 4884, and translating it to ICMPv6 at SIT
or GRE tunnel, we need some extra manipulation in order
to properly forward the extensions.

This patch only takes care of Time Exceeded messages as they
are the ones that typically carry information from various
routers in a fabric during a traceroute session.

It also avoids complex skb logic if the data_len is not
a multiple of 8.

RFC states :

   The "original datagram" field MUST contain at least 128 octets.
   If the original datagram did not contain 128 octets, the
   "original datagram" field MUST be zero padded to 128 octets.

In practice routers use 128 bytes of original datagram, not more.

Initial translation was added in commit ca15a078bd90
("sit: generate icmpv6 error when receiving icmpv4 error")

Signed-off-by: Eric Dumazet 
Cc: Oussama Ghorbel 
Signed-off-by: David S. Miller

ipv6: translate ICMP_TIME_EXCEEDED to ICMPV6_TIME_EXCEED

2016-06-19T05:11:39+00:00

For better traceroute/mtr support for SIT and GRE tunnels,
we translate IPV4 ICMP ICMP_TIME_EXCEEDED to ICMPV6_TIME_EXCEED

We also have to translate the IPv4 source IP address of ICMP
message to IPv6 v4mapped.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

ip6: move ipip6_err_gen_icmpv6_unreach()

2016-06-19T05:11:39+00:00

We want to use this helper from GRE as well, so this is
the time to move it in net/ipv6/icmp.c

Also add a @nhs parameter, since SIT and GRE have different
values for the header(s) to skip.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

sit: correct IP protocol used in ipip6_err

2016-06-17T00:10:30+00:00

Since 32b8a8e59c9c ("sit: add IPv4 over IPv4 support")
ipip6_err() may be called for packets whose IP protocol is
IPPROTO_IPIP as well as those whose IP protocol is IPPROTO_IPV6.

In the case of IPPROTO_IPIP packets the correct protocol value is not
passed to ipv4_update_pmtu() or ipv4_redirect().

This patch resolves this problem by using the IP protocol of the packet
rather than a hard-coded value. This appears to be consistent
with the usage of the protocol of a packet by icmp_socket_deliver()
the caller of ipip6_err().

I was able to exercise the redirect case by using a setup where an ICMP
redirect was received for the destination of the encapsulated packet.
However, it appears that although incorrect the protocol field is not used
in this case and thus no problem manifests.  On inspection it does not
appear that a problem will manifest in the fragmentation needed/update pmtu
case either.

In short I believe this is a cosmetic fix. None the less, the use of
IPPROTO_IPV6 seems wrong and confusing.

Reviewed-by: Dinan Gunawardena 
Signed-off-by: Simon Horman 
Acked-by: YOSHIFUJI Hideaki 
Signed-off-by: David S. Miller

sit: remove unnecessary protocol check in ipip6_tunnel_xmit()

2016-06-09T18:23:37+00:00

ipip6_tunnel_xmit() is called immediately after checking that
skb->protocol is  htons(ETH_P_IPV6) so there is no need
to check it a second time.

Found by inspection.

Signed-off-by: Simon Horman 
Reviewed-by: Dinan Gunawardena 
Signed-off-by: David S. Miller