linux.git/net/ipv6/ip6_gre.c, branch v4.4.76

ip6_gre: fix ip6gre_err() invalid reads

2017-02-18T15:39:26+00:00

[ Upstream commit 7892032cfe67f4bde6fc2ee967e45a8fbaf33756 ]

Andrey Konovalov reported out of bound accesses in ip6gre_err()

If GRE flags contains GRE_KEY, the following expression
*(((__be32 *)p) + (grehlen / 4) - 1)

accesses data ~40 bytes after the expected point, since
grehlen includes the size of IPv6 headers.

Let's use a "struct gre_base_hdr *greh" pointer to make this
code more readable.

p[1] becomes greh->protocol.
grhlen is the GRE header length.

Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Signed-off-by: Eric Dumazet 
Reported-by: Andrey Konovalov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ip6_gre: fix flowi6_proto value in ip6gre_xmit_other()

2016-11-15T06:46:36+00:00

[ Upstream commit db32e4e49ce2b0e5fcc17803d011a401c0a637f6 ]

Similar to commit 3be07244b733 ("ip6_gre: fix flowi6_proto value in
xmit path"), set flowi6_proto to IPPROTO_GRE for output route lookup.

Up until now, ip6gre_xmit_other() has set flowi6_proto to a bogus value.
This affected output route lookup for packets sent on an ip6gretap device
in cases where routing was dependent on the value of flowi6_proto.

Since the correct proto is already set in the tunnel flowi6 template via
commit 252f3f5a1189 ("ip6_gre: Set flowi6_proto as IPPROTO_GRE in xmit
path."), simply delete the line setting the incorrect flowi6_proto value.

Suggested-by: Jiri Benc 
Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Reviewed-by: Shmulik Ladkani 
Signed-off-by: Lance Richardson 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tunnel: Clear IPCB(skb)->opt before dst_link_failure called

2016-04-20T06:41:56+00:00

[ Upstream commit 5146d1f151122e868e594c7b45115d64825aee5f ]

IPCB may contain data from previous layers (in the observed case the
qdisc layer). In the observed scenario, the data was misinterpreted as
ip header options, which later caused the ihl to be set to an invalid
value (<5). This resulted in an infinite loop in the mips implementation
of ip_fast_csum.

This patch clears IPCB(skb)->opt before dst_link_failure can be called for
various types of tunnels. This change only applies to encapsulated ipv4
packets.

The code introduced in 11c21a30 which clears all of IPCB has been removed
to be consistent with these changes, and instead the opt field is cleared
unconditionally in ip_tunnel_xmit. The change in ip_tunnel_xmit applies to
SIT, GRE, and IPIP tunnels.

The relevant vti, l2tp, and pptp functions already contain similar code for
clearing the IPCB.

Signed-off-by: Bernie Harris 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

gre6: allow to update all parameters via rtnl

2015-12-04T21:52:06+00:00

Parameters were updated only if the kernel was unable to find the tunnel
with the new parameters, ie only if core pamareters were updated (keys,
addr, link, type).
Now it's possible to update ttl, hoplimit, flowinfo and flags.

Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Signed-off-by: Nicolas Dichtel 
Signed-off-by: David S. Miller

ip6_gre: Reduce log level in ip6gre_err() to debug

2015-09-24T22:28:43+00:00

Currently error log messages in ip6gre_err are printed at 'warn'
level. This is different to most other tunnel types which don't
print any messages. These log messages don't provide any information
that couldn't be deduced with networking tools. Also it can be annoying
to have one end of the tunnel go down and have the logs fill with
pointless messages such as "Path to destination invalid or inactive!".

This patch reduces the log level of these messages to 'dbg' level to
bring the visible behaviour into line with other tunnel types.

Signed-off-by: Matt Bennett 
Signed-off-by: David S. Miller

ipv6: Fix dst_entry refcnt bugs in ip6_tunnel

2015-09-15T21:53:05+00:00

Problems in the current dst_entry cache in the ip6_tunnel:

1. ip6_tnl_dst_set is racy.  There is no lock to protect it:
   - One major problem is that the dst refcnt gets messed up. F.e.
     the same dst_cache can be released multiple times and then
     triggering the infamous dst refcnt < 0 warning message.
   - Another issue is the inconsistency between dst_cache and
     dst_cookie.

   It can be reproduced by adding and removing the ip6gre tunnel
   while running a super_netperf TCP_CRR test.

2. ip6_tnl_dst_get does not take the dst refcnt before returning
   the dst.

This patch:
1. Create a percpu dst_entry cache in ip6_tnl
2. Use a spinlock to protect the dst_cache operations
3. ip6_tnl_dst_get always takes the dst refcnt before returning

Signed-off-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

ipv6: Rename the dst_cache helper functions in ip6_tunnel

2015-09-15T21:53:04+00:00

It is a prep work to fix the dst_entry refcnt bugs in
ip6_tunnel.

This patch rename:
1. ip6_tnl_dst_check() to ip6_tnl_dst_get() to better
   reflect that it will take a dst refcnt in the next patch.
2. ip6_tnl_dst_store() to ip6_tnl_dst_set() to have a more
   conventional name matching with ip6_tnl_dst_get().

Signed-off-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

ipv6: Refactor common ip6gre_tunnel_init codes

2015-09-15T21:53:04+00:00

It is a prep work to fix the dst_entry refcnt bugs in ip6_tunnel.

This patch refactors some common init codes used by both
ip6gre_tunnel_init and ip6gre_tap_init.

Signed-off-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

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

2015-08-28T04:45:31+00:00

ip6_gre: release cached dst on tunnel removal

2015-08-25T21:33:00+00:00

When a tunnel is deleted, the cached dst entry should be released.

This problem may prevent the removal of a netns (seen with a x-netns IPv6
gre tunnel):
  unregister_netdevice: waiting for lo to become free. Usage count = 3

CC: Dmitry Kozlov 
Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Signed-off-by: huaibin Wang 
Signed-off-by: Nicolas Dichtel 
Signed-off-by: David S. Miller