linux.git/net/ipv6, branch v4.13

ipv6: do not set sk_destruct in IPV6_ADDRFORM sockopt

2017-08-29T17:54:40+00:00

ChunYu found a kernel warn_on during syzkaller fuzzing:

[40226.038539] WARNING: CPU: 5 PID: 23720 at net/ipv4/af_inet.c:152 inet_sock_destruct+0x78d/0x9a0
[40226.144849] Call Trace:
[40226.147590]  
[40226.149859]  dump_stack+0xe2/0x186
[40226.176546]  __warn+0x1a4/0x1e0
[40226.180066]  warn_slowpath_null+0x31/0x40
[40226.184555]  inet_sock_destruct+0x78d/0x9a0
[40226.246355]  __sk_destruct+0xfa/0x8c0
[40226.290612]  rcu_process_callbacks+0xaa0/0x18a0
[40226.336816]  __do_softirq+0x241/0x75e
[40226.367758]  irq_exit+0x1f6/0x220
[40226.371458]  smp_apic_timer_interrupt+0x7b/0xa0
[40226.376507]  apic_timer_interrupt+0x93/0xa0

The warn_on happned when sk->sk_rmem_alloc wasn't 0 in inet_sock_destruct.
As after commit f970bd9e3a06 ("udp: implement memory accounting helpers"),
udp has changed to use udp_destruct_sock as sk_destruct where it would
udp_rmem_release all rmem.

But IPV6_ADDRFORM sockopt sets sk_destruct with inet_sock_destruct after
changing family to PF_INET. If rmem is not 0 at that time, and there is
no place to release rmem before calling inet_sock_destruct, the warn_on
will be triggered.

This patch is to fix it by not setting sk_destruct in IPV6_ADDRFORM sockopt
any more. As IPV6_ADDRFORM sockopt only works for tcp and udp. TCP sock has
already set it's sk_destruct with inet_sock_destruct and UDP has set with
udp_destruct_sock since they're created.

Fixes: f970bd9e3a06 ("udp: implement memory accounting helpers")
Reported-by: ChunYu Wang 
Signed-off-by: Xin Long 
Acked-by: Paolo Abeni 
Signed-off-by: David S. Miller

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2017-08-29T16:37:06+00:00

Steffen Klassert says:

====================
pull request (net): ipsec 2017-08-29

1) Fix dst_entry refcount imbalance when using socket policies.
   From Lorenzo Colitti.

2) Fix locking when adding the ESP trailers.

3) Fix tailroom calculation for the ESP trailer by using
   skb_tailroom instead of skb_availroom.

4) Fix some info leaks in xfrm_user.
   From Mathias Krause.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller

ipv6: set dst.obsolete when a cached route has expired

2017-08-28T22:45:04+00:00

Now it doesn't check for the cached route expiration in ipv6's
dst_ops->check(), because it trusts dst_gc that would clean the
cached route up when it's expired.

The problem is in dst_gc, it would clean the cached route only
when it's refcount is 1. If some other module (like xfrm) keeps
holding it and the module only release it when dst_ops->check()
fails.

But without checking for the cached route expiration, .check()
may always return true. Meanwhile, without releasing the cached
route, dst_gc couldn't del it. It will cause this cached route
never to expire.

This patch is to set dst.obsolete with DST_OBSOLETE_KILL in .gc
when it's expired, and check obsolete != DST_OBSOLETE_FORCE_CHK
in .check.

Note that this is even needed when ipv6 dst_gc timer is removed
one day. It would set dst.obsolete in .redirect and .update_pmtu
instead, and check for cached route expiration when getting it,
just like what ipv4 route does.

Reported-by: Jianlin Shi 
Signed-off-by: Xin Long 
Acked-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

ipv6: fix sparse warning on rt6i_node

2017-08-28T22:34:40+00:00

Commit c5cff8561d2d adds rcu grace period before freeing fib6_node. This
generates a new sparse warning on rt->rt6i_node related code:
  net/ipv6/route.c:1394:30: error: incompatible types in comparison
  expression (different address spaces)
  ./include/net/ip6_fib.h:187:14: error: incompatible types in comparison
  expression (different address spaces)

This commit adds "__rcu" tag for rt6i_node and makes sure corresponding
rcu API is used for it.
After this fix, sparse no longer generates the above warning.

Fixes: c5cff8561d2d ("ipv6: add rcu grace period before freeing fib6_node")
Signed-off-by: Wei Wang 
Acked-by: Eric Dumazet 
Acked-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

udp6: set rx_dst_cookie on rx_dst updates

2017-08-26T03:09:13+00:00

Currently, in the udp6 code, the dst cookie is not initialized/updated
concurrently with the RX dst used by early demux.

As a result, the dst_check() in the early_demux path always fails,
the rx dst cache is always invalidated, and we can't really
leverage significant gain from the demux lookup.

Fix it adding udp6 specific variant of sk_rx_dst_set() and use it
to set the dst cookie when the dst entry is really changed.

The issue is there since the introduction of early demux for ipv6.

Fixes: 5425077d73e0 ("net: ipv6: Add early demux handler for UDP unicast")
Acked-by: Hannes Frederic Sowa 
Signed-off-by: Paolo Abeni 
Signed-off-by: David S. Miller

ipv6: Fix may be used uninitialized warning in rt6_check

2017-08-26T00:05:27+00:00

rt_cookie might be used uninitialized, fix this by
initializing it.

Fixes: c5cff8561d2d ("ipv6: add rcu grace period before freeing fib6_node")
Signed-off-by: Steffen Klassert 
Signed-off-by: David S. Miller

esp: Fix skb tailroom calculation

2017-08-25T07:26:24+00:00

We use skb_availroom to calculate the skb tailroom for the
ESP trailer. skb_availroom calculates the tailroom and
subtracts this value by reserved_tailroom. However
reserved_tailroom is a union with the skb mark. This means
that we subtract the tailroom by the skb mark if set.
Fix this by using skb_tailroom instead.

Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible")
Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible")
Signed-off-by: Steffen Klassert

esp: Fix locking on page fragment allocation

2017-08-25T07:26:12+00:00

We allocate the page fragment for the ESP trailer inside
a spinlock, but consume it outside of the lock. This
is racy as some other cou could get the same page fragment
then. Fix this by consuming the page fragment inside the
lock too.

Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible")
Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible")
Signed-off-by: Steffen Klassert

ipv6: add rcu grace period before freeing fib6_node

2017-08-22T18:03:19+00:00

We currently keep rt->rt6i_node pointing to the fib6_node for the route.
And some functions make use of this pointer to dereference the fib6_node
from rt structure, e.g. rt6_check(). However, as there is neither
refcount nor rcu taken when dereferencing rt->rt6i_node, it could
potentially cause crashes as rt->rt6i_node could be set to NULL by other
CPUs when doing a route deletion.
This patch introduces an rcu grace period before freeing fib6_node and
makes sure the functions that dereference it takes rcu_read_lock().

Note: there is no "Fixes" tag because this bug was there in a very
early stage.

Signed-off-by: Wei Wang 
Acked-by: Eric Dumazet 
Acked-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2017-08-22T17:27:26+00:00

Steffen Klassert says:

====================
pull request (net): ipsec 2017-08-21

1) Fix memleaks when ESP takes an error path.

2) Fix null pointer dereference when creating a sub policy
   that matches the same outer flow as main policy does.
   From Koichiro Den.

3) Fix possible out-of-bound access in xfrm_migrate.
   This patch should go to the stable trees too.
   From Vladis Dronov.

4) ESP can return positive and negative error values,
   so treat both cases as an error.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller