Commit graph

6,097 commits

Author SHA1 Message Date
Dave Jones
30efc09c28 netfilter: ensure number of counters is >0 in do_replace()
commit 1086bbe97a upstream.

After improving setsockopt() coverage in trinity, I started triggering
vmalloc failures pretty reliably from this code path:

warn_alloc_failed+0xe9/0x140
__vmalloc_node_range+0x1be/0x270
vzalloc+0x4b/0x50
__do_replace+0x52/0x260 [ip_tables]
do_ipt_set_ctl+0x15d/0x1d0 [ip_tables]
nf_setsockopt+0x65/0x90
ip_setsockopt+0x61/0xa0
raw_setsockopt+0x16/0x60
sock_common_setsockopt+0x14/0x20
SyS_setsockopt+0x71/0xd0

It turns out we don't validate that the num_counters field in the
struct we pass in from userspace is initialized.

The same problem also exists in ebtables, arptables, ipv6, and the
compat variants.

Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22 22:38:31 +01:00
Florian Westphal
019475d646 netfilter: x_tables: introduce and use xt_copy_counters_from_user
commit d7591f0c41 upstream.

The three variants use same copy&pasted code, condense this into a
helper and use that.

Make sure info.name is 0-terminated.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22 22:38:31 +01:00
Florian Westphal
49b9f189fc netfilter: x_tables: do compat validation via translate_table
commit 09d9686047 upstream.

This looks like refactoring, but its also a bug fix.

Problem is that the compat path (32bit iptables, 64bit kernel) lacks a few
sanity tests that are done in the normal path.

For example, we do not check for underflows and the base chain policies.

While its possible to also add such checks to the compat path, its more
copy&pastry, for instance we cannot reuse check_underflow() helper as
e->target_offset differs in the compat case.

Other problem is that it makes auditing for validation errors harder; two
places need to be checked and kept in sync.

At a high level 32 bit compat works like this:
1- initial pass over blob:
   validate match/entry offsets, bounds checking
   lookup all matches and targets
   do bookkeeping wrt. size delta of 32/64bit structures
   assign match/target.u.kernel pointer (points at kernel
   implementation, needed to access ->compatsize etc.)

2- allocate memory according to the total bookkeeping size to
   contain the translated ruleset

3- second pass over original blob:
   for each entry, copy the 32bit representation to the newly allocated
   memory.  This also does any special match translations (e.g.
   adjust 32bit to 64bit longs, etc).

4- check if ruleset is free of loops (chase all jumps)

5-first pass over translated blob:
   call the checkentry function of all matches and targets.

The alternative implemented by this patch is to drop steps 3&4 from the
compat process, the translation is changed into an intermediate step
rather than a full 1:1 translate_table replacement.

In the 2nd pass (step #3), change the 64bit ruleset back to a kernel
representation, i.e. put() the kernel pointer and restore ->u.user.name .

This gets us a 64bit ruleset that is in the format generated by a 64bit
iptables userspace -- we can then use translate_table() to get the
'native' sanity checks.

This has two drawbacks:

1. we re-validate all the match and target entry structure sizes even
though compat translation is supposed to never generate bogus offsets.
2. we put and then re-lookup each match and target.

THe upside is that we get all sanity tests and ruleset validations
provided by the normal path and can remove some duplicated compat code.

iptables-restore time of autogenerated ruleset with 300k chains of form
-A CHAIN0001 -m limit --limit 1/s -j CHAIN0002
-A CHAIN0002 -m limit --limit 1/s -j CHAIN0003

shows no noticeable differences in restore times:
old:   0m30.796s
new:   0m31.521s
64bit: 0m25.674s

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[bwh: Backported to 3.16: deleted code is a little different]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22 22:38:31 +01:00
Florian Westphal
452fdfcd43 netfilter: x_tables: xt_compat_match_from_user doesn't need a retval
commit 0188346f21 upstream.

Always returned 0.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22 22:38:31 +01:00
Florian Westphal
a33db92ff1 netfilter: ip_tables: simplify translate_compat_table args
commit 7d3f843eed upstream.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22 22:38:30 +01:00
Florian Westphal
c2fcc885cb netfilter: arp_tables: simplify translate_compat_table args
commit 8dddd32756 upstream.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[bwh: Backported to 3.6: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22 22:38:30 +01:00
Florian Westphal
35ea6762cc netfilter: x_tables: check for bogus target offset
commit ce683e5f9d upstream.

We're currently asserting that targetoff + targetsize <= nextoff.

Extend it to also check that targetoff is >= sizeof(xt_entry).
Since this is generic code, add an argument pointing to the start of the
match/target, we can then derive the base structure size from the delta.

We also need the e->elems pointer in a followup change to validate matches.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22 22:38:30 +01:00
Florian Westphal
76db4db16a netfilter: x_tables: add compat version of xt_check_entry_offsets
commit fc1221b3a1 upstream.

32bit rulesets have different layout and alignment requirements, so once
more integrity checks get added to xt_check_entry_offsets it will reject
well-formed 32bit rulesets.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22 22:38:29 +01:00
Florian Westphal
30a24c6637 netfilter: x_tables: kill check_entry helper
commit aa412ba225 upstream.

Once we add more sanity testing to xt_check_entry_offsets it
becomes relvant if we're expecting a 32bit 'config_compat' blob
or a normal one.

Since we already have a lot of similar-named functions (check_entry,
compat_check_entry, find_and_check_entry, etc.) and the current
incarnation is short just fold its contents into the callers.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22 22:38:29 +01:00
Florian Westphal
b39be8f153 netfilter: x_tables: add and use xt_check_entry_offsets
commit 7d35812c32 upstream.

Currently arp/ip and ip6tables each implement a short helper to check that
the target offset is large enough to hold one xt_entry_target struct and
that t->u.target_size fits within the current rule.

Unfortunately these checks are not sufficient.

To avoid adding new tests to all of ip/ip6/arptables move the current
checks into a helper, then extend this helper in followup patches.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22 22:38:29 +01:00
Florian Westphal
3d2d4415b1 netfilter: x_tables: don't move to non-existent next rule
commit f24e230d25 upstream.

Ben Hawkes says:

 In the mark_source_chains function (net/ipv4/netfilter/ip_tables.c) it
 is possible for a user-supplied ipt_entry structure to have a large
 next_offset field. This field is not bounds checked prior to writing a
 counter value at the supplied offset.

Base chains enforce absolute verdict.

User defined chains are supposed to end with an unconditional return,
xtables userspace adds them automatically.

But if such return is missing we will move to non-existent next rule.

Reported-by: Ben Hawkes <hawkes@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22 22:38:29 +01:00
Eric Dumazet
c628749966 tcp: make challenge acks less predictable
commit 75ff39ccc1 upstream.

Yue Cao claims that current host rate limiting of challenge ACKS
(RFC 5961) could leak enough information to allow a patient attacker
to hijack TCP sessions. He will soon provide details in an academic
paper.

This patch increases the default limit from 100 to 1000, and adds
some randomization so that the attacker can no longer hijack
sessions without spending a considerable amount of probes.

Based on initial analysis and patch from Linus.

Note that we also have per socket rate limiting, so it is tempting
to remove the host limit in the future.

v2: randomize the count of challenge acks per second, not the period.

Fixes: 282f23c6ee ("tcp: implement RFC 5961 3.2")
Reported-by: Yue Cao <ycao009@ucr.edu>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16:
 - Adjust context
 - Use ACCESS_ONCE() instead of {READ,WRITE}_ONCE()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22 22:38:28 +01:00
Florian Westphal
366d36a813 netfilter: x_tables: fix unconditional helper
commit 54d83fc74a upstream.

Ben Hawkes says:

 In the mark_source_chains function (net/ipv4/netfilter/ip_tables.c) it
 is possible for a user-supplied ipt_entry structure to have a large
 next_offset field. This field is not bounds checked prior to writing a
 counter value at the supplied offset.

Problem is that mark_source_chains should not have been called --
the rule doesn't have a next entry, so its supposed to return
an absolute verdict of either ACCEPT or DROP.

However, the function conditional() doesn't work as the name implies.
It only checks that the rule is using wildcard address matching.

However, an unconditional rule must also not be using any matches
(no -m args).

The underflow validator only checked the addresses, therefore
passing the 'unconditional absolute verdict' test, while
mark_source_chains also tested for presence of matches, and thus
proceeeded to the next (not-existent) rule.

Unify this so that all the callers have same idea of 'unconditional rule'.

Reported-by: Ben Hawkes <hawkes@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-05-01 00:06:15 +02:00
Florian Westphal
113ec64467 netfilter: x_tables: make sure e->next_offset covers remaining blob size
commit 6e94e0cfb0 upstream.

Otherwise this function may read data beyond the ruleset blob.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-05-01 00:06:10 +02:00
Florian Westphal
dc385be2ea netfilter: x_tables: validate e->target_offset early
commit bdf533de69 upstream.

We should check that e->target_offset is sane before
mark_source_chains gets called since it will fetch the target entry
for loop detection.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-05-01 00:06:10 +02:00
Jesse Gross
23cca87ff2 tunnels: Don't apply GRO to multiple layers of encapsulation.
commit fac8e0f579 upstream.

When drivers express support for TSO of encapsulated packets, they
only mean that they can do it for one layer of encapsulation.
Supporting additional levels would mean updating, at a minimum,
more IP length fields and they are unaware of this.

No encapsulation device expresses support for handling offloaded
encapsulated packets, so we won't generate these types of frames
in the transmit path. However, GRO doesn't have a check for
multiple levels of encapsulation and will attempt to build them.

UDP tunnel GRO actually does prevent this situation but it only
handles multiple UDP tunnels stacked on top of each other. This
generalizes that solution to prevent any kind of tunnel stacking
that would cause problems.

Fixes: bf5a755f ("net-gre-gro: Add GRE support to the GRO stack")
Signed-off-by: Jesse Gross <jesse@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16:
 - Drop the ipip and sit cases
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-05-01 00:06:03 +02:00
David S. Miller
8b03d90864 ipv4: Don't do expensive useless work during inetdev destroy.
commit fbd40ea018 upstream.

When an inetdev is destroyed, every address assigned to the interface
is removed.  And in this scenerio we do two pointless things which can
be very expensive if the number of assigned interfaces is large:

1) Address promotion.  We are deleting all addresses, so there is no
   point in doing this.

2) A full nf conntrack table purge for every address.  We only need to
   do this once, as is already caught by the existing
   masq_dev_notifier so masq_inet_event() can skip this.

Reported-by: Solar Designer <solar@openwall.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Moritz Muehlenhoff <jmm@inutil.org>
[ luis: backported to 3.16:
  - file rename: nf_nat_masquerade_ipv4.c -> ipt_MASQUERADE.c ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-03-29 15:53:41 +01:00
Benjamin Poirier
842ab65a60 mld, igmp: Fix reserved tailroom calculation
commit 1837b2e2bc upstream.

The current reserved_tailroom calculation fails to take hlen and tlen into
account.

skb:
[__hlen__|__data____________|__tlen___|__extra__]
^                                               ^
head                                            skb_end_offset

In this representation, hlen + data + tlen is the size passed to alloc_skb.
"extra" is the extra space made available in __alloc_skb because of
rounding up by kmalloc. We can reorder the representation like so:

[__hlen__|__data____________|__extra__|__tlen___]
^                                               ^
head                                            skb_end_offset

The maximum space available for ip headers and payload without
fragmentation is min(mtu, data + extra). Therefore,
reserved_tailroom
= data + extra + tlen - min(mtu, data + extra)
= skb_end_offset - hlen - min(mtu, skb_end_offset - hlen - tlen)
= skb_tailroom - min(mtu, skb_tailroom - tlen) ; after skb_reserve(hlen)

Compare the second line to the current expression:
reserved_tailroom = skb_end_offset - min(mtu, skb_end_offset)
and we can see that hlen and tlen are not taken into account.

The min() in the third line can be expanded into:
if mtu < skb_tailroom - tlen:
	reserved_tailroom = skb_tailroom - mtu
else:
	reserved_tailroom = tlen

Depending on hlen, tlen, mtu and the number of multicast address records,
the current code may output skbs that have less tailroom than
dev->needed_tailroom or it may output more skbs than needed because not all
space available is used.

Fixes: 4c672e4b ("ipv6: mld: fix add_grhead skb_over_panic for devs with large MTUs")
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-03-24 10:01:13 +00:00
Konstantin Khlebnikov
702fd08779 tcp: convert cached rtt from usec to jiffies when feeding initial rto
commit 9bdfb3b79e upstream.

Currently it's converted into msecs, thus HZ=1000 intact.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Fixes: 740b0f1841 ("tcp: switch rtt estimations to usec resolution")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-03-24 10:01:13 +00:00
Anton Protopopov
1a0d99e260 rtnl: RTM_GETNETCONF: fix wrong return value
commit a97eb33ff2 upstream.

An error response from a RTM_GETNETCONF request can return the positive
error value EINVAL in the struct nlmsgerr that can mislead userspace.

Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-03-24 10:00:46 +00:00
Xin Long
5ab10d3d73 route: check and remove route cache when we get route
commit deed49df73 upstream.

Since the gc of ipv4 route was removed, the route cached would has
no chance to be removed, and even it has been timeout, it still could
be used, cause no code to check it's expires.

Fix this issue by checking  and removing route cache when we get route.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-03-24 10:00:46 +00:00
Eric Dumazet
035c7999a9 ipv4: fix memory leaks in ip_cmsg_send() callers
commit 919483096b upstream.

Dmitry reported memory leaks of IP options allocated in
ip_cmsg_send() when/if this function returns an error.

Callers are responsible for the freeing.

Many thanks to Dmitry for the report and diagnostic.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-03-24 10:00:45 +00:00
Hans Westgaard Ry
1f3c213094 net:Add sysctl_max_skb_frags
commit 5f74f82ea3 upstream.

Devices may have limits on the number of fragments in an skb they support.
Current codebase uses a constant as maximum for number of fragments one
skb can hold and use.
When enabling scatter/gather and running traffic with many small messages
the codebase uses the maximum number of fragments and may thereby violate
the max for certain devices.
The patch introduces a global variable as max number of fragments.

Signed-off-by: Hans Westgaard Ry <hans.westgaard.ry@oracle.com>
Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-03-24 10:00:44 +00:00
Eric Dumazet
836bb5f7fb tcp: fix NULL deref in tcp_v4_send_ack()
commit e62a123b8e upstream.

Neal reported crashes with this stack trace :

 RIP: 0010:[<ffffffff8c57231b>] tcp_v4_send_ack+0x41/0x20f
...
 CR2: 0000000000000018 CR3: 000000044005c000 CR4: 00000000001427e0
...
  [<ffffffff8c57258e>] tcp_v4_reqsk_send_ack+0xa5/0xb4
  [<ffffffff8c1a7caa>] tcp_check_req+0x2ea/0x3e0
  [<ffffffff8c19e420>] tcp_rcv_state_process+0x850/0x2500
  [<ffffffff8c1a6d21>] tcp_v4_do_rcv+0x141/0x330
  [<ffffffff8c56cdb2>] sk_backlog_rcv+0x21/0x30
  [<ffffffff8c098bbd>] tcp_recvmsg+0x75d/0xf90
  [<ffffffff8c0a8700>] inet_recvmsg+0x80/0xa0
  [<ffffffff8c17623e>] sock_aio_read+0xee/0x110
  [<ffffffff8c066fcf>] do_sync_read+0x6f/0xa0
  [<ffffffff8c0673a1>] SyS_read+0x1e1/0x290
  [<ffffffff8c5ca262>] system_call_fastpath+0x16/0x1b

The problem here is the skb we provide to tcp_v4_send_ack() had to
be parked in the backlog of a new TCP fastopen child because this child
was owned by the user at the time an out of window packet arrived.

Before queuing a packet, TCP has to set skb->dev to NULL as the device
could disappear before packet is removed from the queue.

Fix this issue by using the net pointer provided by the socket (being a
timewait or a request socket).

IPv6 is immune to the bug : tcp_v6_send_response() already gets the net
pointer from the socket if provided.

Fixes: 168a8f5805 ("tcp: TCP Fast Open Server - main code path")
Reported-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jerry Chu <hkchu@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-03-09 10:38:49 +00:00
Dan Streetman
4c5629357e xfrm: dst_entries_init() per-net dst_ops
commit a8a572a6b5 upstream.

Remove the dst_entries_init/destroy calls for xfrm4 and xfrm6 dst_ops
templates; their dst_entries counters will never be used.  Move the
xfrm dst_ops initialization from the common xfrm/xfrm_policy.c to
xfrm4/xfrm4_policy.c and xfrm6/xfrm6_policy.c, and call dst_entries_init
and dst_entries_destroy for each net namespace.

The ipv4 and ipv6 xfrms each create dst_ops template, and perform
dst_entries_init on the templates.  The template values are copied to each
net namespace's xfrm.xfrm*_dst_ops.  The problem there is the dst_ops
pcpuc_entries field is a percpu counter and cannot be used correctly by
simply copying it to another object.

The result of this is a very subtle bug; changes to the dst entries
counter from one net namespace may sometimes get applied to a different
net namespace dst entries counter.  This is because of how the percpu
counter works; it has a main count field as well as a pointer to the
percpu variables.  Each net namespace maintains its own main count
variable, but all point to one set of percpu variables.  When any net
namespace happens to change one of the percpu variables to outside its
small batch range, its count is moved to the net namespace's main count
variable.  So with multiple net namespaces operating concurrently, the
dst_ops entries counter can stray from the actual value that it should
be; if counts are consistently moved from one net namespace to another
(which my testing showed is likely), then one net namespace winds up
with a negative dst_ops count while another winds up with a continually
increasing count, eventually reaching its gc_thresh limit, which causes
all new traffic on the net namespace to fail with -ENOBUFS.

Signed-off-by: Dan Streetman <dan.streetman@canonical.com>
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-01-28 11:57:51 +00:00
Neal Cardwell
2edc978386 tcp_yeah: don't set ssthresh below 2
commit 83d15e70c4 upstream.

For tcp_yeah, use an ssthresh floor of 2, the same floor used by Reno
and CUBIC, per RFC 5681 (equation 4).

tcp_yeah_ssthresh() was sometimes returning a 0 or negative ssthresh
value if the intended reduction is as big or bigger than the current
cwnd. Congestion control modules should never return a zero or
negative ssthresh. A zero ssthresh generally results in a zero cwnd,
causing the connection to stall. A negative ssthresh value will be
interpreted as a u32 and will set a target cwnd for PRR near 4
billion.

Oleksandr Natalenko reported that a system using tcp_yeah with ECN
could see a warning about a prior_cwnd of 0 in
tcp_cwnd_reduction(). Testing verified that this was due to
tcp_yeah_ssthresh() misbehaving in this way.

Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-01-28 10:49:49 +00:00
Eric Dumazet
f7f4fb819a udp: properly support MSG_PEEK with truncated buffers
commit 197c949e77 upstream.

Backport of this upstream commit into stable kernels :
89c22d8c3b ("net: Fix skb csum races when peeking")
exposed a bug in udp stack vs MSG_PEEK support, when user provides
a buffer smaller than skb payload.

In this case,
skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr),
                                 msg->msg_iov);
returns -EFAULT.

This bug does not happen in upstream kernels since Al Viro did a great
job to replace this into :
skb_copy_and_csum_datagram_msg(skb, sizeof(struct udphdr), msg);
This variant is safe vs short buffers.

For the time being, instead reverting Herbert Xu patch and add back
skb->ip_summed invalid changes, simply store the result of
udp_lib_checksum_complete() so that we avoid computing the checksum a
second time, and avoid the problematic
skb_copy_and_csum_datagram_iovec() call.

This patch can be applied on recent kernels as it avoids a double
checksumming, then backported to stable kernels as a bug fix.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-01-25 10:44:08 +00:00
Luis Henriques
0920a7112e Revert "[stable-only] net: add length argument to skb_copy_and_csum_datagram_iovec"
This reverts commit fa89ae5548.

As reported by Michal Kubecek, the backport of commit 89c22d8c3b
("net: Fix skb csum races when peeking") exposed an upstream bug.
It is being reverted and replaced by a better fix.

Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-01-25 10:44:07 +00:00
Andrew Lunn
fd4a0bf3fa ipv4: igmp: Allow removing groups from a removed interface
commit 4eba7bb1d7 upstream.

When a multicast group is joined on a socket, a struct ip_mc_socklist
is appended to the sockets mc_list containing information about the
joined group.

If the interface is hot unplugged, this entry becomes stale. Prior to
commit 52ad353a53 ("igmp: fix the problem when mc leave group") it
was possible to remove the stale entry by performing a
IP_DROP_MEMBERSHIP, passing either the old ifindex or ip address on
the interface. However, this fix enforces that the interface must
still exist. Thus with time, the number of stale entries grows, until
sysctl_igmp_max_memberships is reached and then it is not possible to
join and more groups.

The previous patch fixes an issue where a IP_DROP_MEMBERSHIP is
performed without specifying the interface, either by ifindex or ip
address. However here we do supply one of these. So loosen the
restriction on device existence to only apply when the interface has
not been specified. This then restores the ability to clean up the
stale entries.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Fixes: 52ad353a53 "(igmp: fix the problem when mc leave group")
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-01-05 12:08:25 +00:00
Hannes Frederic Sowa
c289dc9fea net: add validation for the socket syscall protocol argument
commit 79462ad02e upstream.

郭永刚 reported that one could simply crash the kernel as root by
using a simple program:

	int socket_fd;
	struct sockaddr_in addr;
	addr.sin_port = 0;
	addr.sin_addr.s_addr = INADDR_ANY;
	addr.sin_family = 10;

	socket_fd = socket(10,3,0x40000000);
	connect(socket_fd , &addr,16);

AF_INET, AF_INET6 sockets actually only support 8-bit protocol
identifiers. inet_sock's skc_protocol field thus is sized accordingly,
thus larger protocol identifiers simply cut off the higher bits and
store a zero in the protocol fields.

This could lead to e.g. NULL function pointer because as a result of
the cut off inet_num is zero and we call down to inet_autobind, which
is NULL for raw sockets.

kernel: Call Trace:
kernel:  [<ffffffff816db90e>] ? inet_autobind+0x2e/0x70
kernel:  [<ffffffff816db9a4>] inet_dgram_connect+0x54/0x80
kernel:  [<ffffffff81645069>] SYSC_connect+0xd9/0x110
kernel:  [<ffffffff810ac51b>] ? ptrace_notify+0x5b/0x80
kernel:  [<ffffffff810236d8>] ? syscall_trace_enter_phase2+0x108/0x200
kernel:  [<ffffffff81645e0e>] SyS_connect+0xe/0x10
kernel:  [<ffffffff81779515>] tracesys_phase2+0x84/0x89

I found no particular commit which introduced this problem.

CVE: CVE-2015-8543
Cc: Cong Wang <cwang@twopensource.com>
Reported-by: 郭永刚 <guoyonggang@360.cn>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2016-01-04 17:20:45 +00:00
lucien
626dcb656b netfilter: ipt_rpfilter: remove the nh_scope test in rpfilter_lookup_reverse
commit cc4998febd upstream.

--accept-local  option works for res.type == RTN_LOCAL, which should be
from the local table, but there, the fib_info's nh->nh_scope =
RT_SCOPE_NOWHERE ( > RT_SCOPE_HOST). in fib_create_info().

	if (cfg->fc_scope == RT_SCOPE_HOST) {
		struct fib_nh *nh = fi->fib_nh;

		/* Local address is added. */
		if (nhs != 1 || nh->nh_gw)
			goto err_inval;
		nh->nh_scope = RT_SCOPE_NOWHERE;   <===
		nh->nh_dev = dev_get_by_index(net, fi->fib_nh->nh_oif);
		err = -ENODEV;
		if (!nh->nh_dev)
			goto failure;

but in our rpfilter_lookup_reverse():

	if (dev_match || flags & XT_RPFILTER_LOOSE)
		return FIB_RES_NH(res).nh_scope <= RT_SCOPE_HOST;

if nh->nh_scope > RT_SCOPE_HOST, it will fail. --accept-local option
will never be passed.

it seems the test is bogus and can be removed to fix this issue.

	if (dev_match || flags & XT_RPFILTER_LOOSE)
		return FIB_RES_NH(res).nh_scope <= RT_SCOPE_HOST;

ipv6 does not have this issue.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-12-18 16:06:40 +00:00
Nikolay Aleksandrov
85425a8876 net: ipmr: fix static mfc/dev leaks on table destruction
commit 0e615e9601 upstream.

When destroying an mrt table the static mfc entries and the static
devices are kept, which leads to devices that can never be destroyed
(because of refcnt taken) and leaked memory, for example:
unreferenced object 0xffff880034c144c0 (size 192):
  comm "mfc-broken", pid 4777, jiffies 4320349055 (age 46001.964s)
  hex dump (first 32 bytes):
    98 53 f0 34 00 88 ff ff 98 53 f0 34 00 88 ff ff  .S.4.....S.4....
    ef 0a 0a 14 01 02 03 04 00 00 00 00 01 00 00 00  ................
  backtrace:
    [<ffffffff815c1b9e>] kmemleak_alloc+0x4e/0xb0
    [<ffffffff811ea6e0>] kmem_cache_alloc+0x190/0x300
    [<ffffffff815931cb>] ip_mroute_setsockopt+0x5cb/0x910
    [<ffffffff8153d575>] do_ip_setsockopt.isra.11+0x105/0xff0
    [<ffffffff8153e490>] ip_setsockopt+0x30/0xa0
    [<ffffffff81564e13>] raw_setsockopt+0x33/0x90
    [<ffffffff814d1e14>] sock_common_setsockopt+0x14/0x20
    [<ffffffff814d0b51>] SyS_setsockopt+0x71/0xc0
    [<ffffffff815cdbf6>] entry_SYSCALL_64_fastpath+0x16/0x7a
    [<ffffffffffffffff>] 0xffffffffffffffff

Make sure that everything is cleaned on netns destruction.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-12-18 16:06:22 +00:00
Eric Dumazet
9a81e0e1dd tcp: initialize tp->copied_seq in case of cross SYN connection
commit 142a2e7ece upstream.

Dmitry provided a syzkaller (http://github.com/google/syzkaller)
generated program that triggers the WARNING at
net/ipv4/tcp.c:1729 in tcp_recvmsg() :

WARN_ON(tp->copied_seq != tp->rcv_nxt &&
        !(flags & (MSG_PEEK | MSG_TRUNC)));

His program is specifically attempting a Cross SYN TCP exchange,
that we support (for the pleasure of hackers ?), but it looks we
lack proper tcp->copied_seq initialization.

Thanks again Dmitry for your report and testings.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-12-18 16:06:21 +00:00
Eric Dumazet
d230c3a0df tcp: md5: fix lockdep annotation
commit 1b8e6a01e1 upstream.

When a passive TCP is created, we eventually call tcp_md5_do_add()
with sk pointing to the child. It is not owner by the user yet (we
will add this socket into listener accept queue a bit later anyway)

But we do own the spinlock, so amend the lockdep annotation to avoid
following splat :

[ 8451.090932] net/ipv4/tcp_ipv4.c:923 suspicious rcu_dereference_protected() usage!
[ 8451.090932]
[ 8451.090932] other info that might help us debug this:
[ 8451.090932]
[ 8451.090934]
[ 8451.090934] rcu_scheduler_active = 1, debug_locks = 1
[ 8451.090936] 3 locks held by socket_sockopt_/214795:
[ 8451.090936]  #0:  (rcu_read_lock){.+.+..}, at: [<ffffffff855c6ac1>] __netif_receive_skb_core+0x151/0xe90
[ 8451.090947]  #1:  (rcu_read_lock){.+.+..}, at: [<ffffffff85618143>] ip_local_deliver_finish+0x43/0x2b0
[ 8451.090952]  #2:  (slock-AF_INET){+.-...}, at: [<ffffffff855acda5>] sk_clone_lock+0x1c5/0x500
[ 8451.090958]
[ 8451.090958] stack backtrace:
[ 8451.090960] CPU: 7 PID: 214795 Comm: socket_sockopt_

[ 8451.091215] Call Trace:
[ 8451.091216]  <IRQ>  [<ffffffff856fb29c>] dump_stack+0x55/0x76
[ 8451.091229]  [<ffffffff85123b5b>] lockdep_rcu_suspicious+0xeb/0x110
[ 8451.091235]  [<ffffffff8564544f>] tcp_md5_do_add+0x1bf/0x1e0
[ 8451.091239]  [<ffffffff85645751>] tcp_v4_syn_recv_sock+0x1f1/0x4c0
[ 8451.091242]  [<ffffffff85642b27>] ? tcp_v4_md5_hash_skb+0x167/0x190
[ 8451.091246]  [<ffffffff85647c78>] tcp_check_req+0x3c8/0x500
[ 8451.091249]  [<ffffffff856451ae>] ? tcp_v4_inbound_md5_hash+0x11e/0x190
[ 8451.091253]  [<ffffffff85647170>] tcp_v4_rcv+0x3c0/0x9f0
[ 8451.091256]  [<ffffffff85618143>] ? ip_local_deliver_finish+0x43/0x2b0
[ 8451.091260]  [<ffffffff856181b6>] ip_local_deliver_finish+0xb6/0x2b0
[ 8451.091263]  [<ffffffff85618143>] ? ip_local_deliver_finish+0x43/0x2b0
[ 8451.091267]  [<ffffffff85618d38>] ip_local_deliver+0x48/0x80
[ 8451.091270]  [<ffffffff85618510>] ip_rcv_finish+0x160/0x700
[ 8451.091273]  [<ffffffff8561900e>] ip_rcv+0x29e/0x3d0
[ 8451.091277]  [<ffffffff855c74b7>] __netif_receive_skb_core+0xb47/0xe90

Fixes: a8afca0329 ("tcp: md5: protects md5sig_info with RCU")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-12-18 16:06:20 +00:00
Yuchung Cheng
dec3ceaf21 tcp: apply Kern's check on RTTs used for congestion control
commit 9e45a3e36b upstream.

Currently ca_seq_rtt_us does not use Kern's check. Fix that by
checking if any packet acked is a retransmit, for both RTT used
for RTT estimation and congestion control.

Fixes: 5b08e47ca ("tcp: prefer packet timing to TS-ECR for RTT")
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-12-13 17:49:37 +00:00
Eric W. Biederman
9c84eab050 ipv4: Fix ip_queue_xmit to pass sk into ip_local_out_sk
commit 850dcc4d4d upstream.

After a packet has been encapsulated by a tunnel we should use the
tunnel sockets local multicast loopback flag to control if the
encapsulated packet should be locally loopback back.

Pass sk into ip_local_out_sk so that in the rare case we are dealing
with a tunneled packet whose tunnel destination address is a multicast
address the kernel properly decides to loopback this packet.

In practice I don't think this matters as ip_queue_xmit is used by
tcp, l2tp and sctp none of which I am aware of uses ip level
multicasting as they are all point to point communications protocols.
Let's fix this before someone uses ip_queue_xmit for a tunnel protocol
that does use multicast.

Fixes: aad88724c9 ("ipv4: add a sock pointer to dst->output() path.")
Fixes: b0270e9101 ("ipv4: add a sock pointer to ip_queue_xmit()")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-12-13 17:49:31 +00:00
Ani Sinha
bd8d8486bd ipmr: fix possible race resulting from improper usage of IP_INC_STATS_BH() in preemptible context.
commit 44f49dd8b5 upstream.

Fixes the following kernel BUG :

BUG: using __this_cpu_add() in preemptible [00000000] code: bash/2758
caller is __this_cpu_preempt_check+0x13/0x15
CPU: 0 PID: 2758 Comm: bash Tainted: P           O   3.18.19 #2
 ffffffff8170eaca ffff880110d1b788 ffffffff81482b2a 0000000000000000
 0000000000000000 ffff880110d1b7b8 ffffffff812010ae ffff880007cab800
 ffff88001a060800 ffff88013a899108 ffff880108b84240 ffff880110d1b7c8
Call Trace:
[<ffffffff81482b2a>] dump_stack+0x52/0x80
[<ffffffff812010ae>] check_preemption_disabled+0xce/0xe1
[<ffffffff812010d4>] __this_cpu_preempt_check+0x13/0x15
[<ffffffff81419d60>] ipmr_queue_xmit+0x647/0x70c
[<ffffffff8141a154>] ip_mr_forward+0x32f/0x34e
[<ffffffff8141af76>] ip_mroute_setsockopt+0xe03/0x108c
[<ffffffff810553fc>] ? get_parent_ip+0x11/0x42
[<ffffffff810e6974>] ? pollwake+0x4d/0x51
[<ffffffff81058ac0>] ? default_wake_function+0x0/0xf
[<ffffffff810553fc>] ? get_parent_ip+0x11/0x42
[<ffffffff810613d9>] ? __wake_up_common+0x45/0x77
[<ffffffff81486ea9>] ? _raw_spin_unlock_irqrestore+0x1d/0x32
[<ffffffff810618bc>] ? __wake_up_sync_key+0x4a/0x53
[<ffffffff8139a519>] ? sock_def_readable+0x71/0x75
[<ffffffff813dd226>] do_ip_setsockopt+0x9d/0xb55
[<ffffffff81429818>] ? unix_seqpacket_sendmsg+0x3f/0x41
[<ffffffff813963fe>] ? sock_sendmsg+0x6d/0x86
[<ffffffff813959d4>] ? sockfd_lookup_light+0x12/0x5d
[<ffffffff8139650a>] ? SyS_sendto+0xf3/0x11b
[<ffffffff810d5738>] ? new_sync_read+0x82/0xaa
[<ffffffff813ddd19>] compat_ip_setsockopt+0x3b/0x99
[<ffffffff813fb24a>] compat_raw_setsockopt+0x11/0x32
[<ffffffff81399052>] compat_sock_common_setsockopt+0x18/0x1f
[<ffffffff813c4d05>] compat_SyS_setsockopt+0x1a9/0x1cf
[<ffffffff813c4149>] compat_SyS_socketcall+0x180/0x1e3
[<ffffffff81488ea1>] cstar_dispatch+0x7/0x1e

Signed-off-by: Ani Sinha <ani@arista.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-12-09 11:40:52 +00:00
Eric Dumazet
45f29add23 ipv6: gre: support SIT encapsulation
commit 7e3b6e7423 upstream.

gre_gso_segment() chokes if SIT frames were aggregated by GRO engine.

Fixes: 61c1db7fae ("ipv6: sit: add GSO/TSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-11-16 11:27:18 +00:00
Sabrina Dubroca
fa89ae5548 [stable-only] net: add length argument to skb_copy_and_csum_datagram_iovec
Without this length argument, we can read past the end of the iovec in
memcpy_toiovec because we have no way of knowing the total length of the
iovec's buffers.

This is needed for stable kernels where 89c22d8c3b ("net: Fix skb
csum races when peeking") has been backported but that don't have the
ioviter conversion, which is almost all the stable trees <= 3.18.

This also fixes a kernel crash for NFS servers when the client uses
 -onfsvers=3,proto=udp to mount the export.

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
[ luis: backported to 3.16:
  - dropped changes to net/rxrpc/ar-recvmsg.c ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-10-28 10:33:22 +00:00
Florian Westphal
7685e48d1c net: gso: use feature flag argument in all protocol gso handlers
commit 1e16aa3ddf upstream.

skb_gso_segment() has a 'features' argument representing offload features
available to the output path.

A few handlers, e.g. GRE, instead re-fetch the features of skb->dev and use
those instead of the provided ones when handing encapsulation/tunnels.

Depending on dev->hw_enc_features of the output device skb_gso_segment() can
then return NULL even when the caller has disabled all GSO feature bits,
as segmentation of inner header thinks device will take care of segmentation.

This e.g. affects the tbf scheduler, which will silently drop GRE-encap GSO skbs
that did not fit the remaining token quota as the segmentation does not work
when device supports corresponding hw offload capabilities.

Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: used davem's backport to 3.14 ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-08-27 14:27:14 +01:00
Eric Dumazet
fd6a8a1505 udp: fix dst races with multicast early demux
commit 10e2eb878f upstream.

Multicast dst are not cached. They carry DST_NOCACHE.

As mentioned in commit f886497212 ("ipv4: fix dst race in
sk_dst_get()"), these dst need special care before caching them
into a socket.

Caching them is allowed only if their refcnt was not 0, ie we
must use atomic_inc_not_zero()

Also, we must use READ_ONCE() to fetch sk->sk_rx_dst, as mentioned
in commit d0c294c53a ("tcp: prevent fetching dst twice in early demux
code")

Fixes: 421b3885bf ("udp: ipv4: Add udp early demux")
Tested-by: Gregory Hoggarth <Gregory.Hoggarth@alliedtelesis.co.nz>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Gregory Hoggarth <Gregory.Hoggarth@alliedtelesis.co.nz>
Reported-by: Alex Gartrell <agartrell@fb.com>
Cc: Michal Kubeček <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: used davem's backport to 3.14 ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-08-27 14:19:02 +01:00
Eric Dumazet
f3106f51fa ipv6: lock socket in ip6_datagram_connect()
commit 03645a11a5 upstream.

ip6_datagram_connect() is doing a lot of socket changes without
socket being locked.

This looks wrong, at least for udp_lib_rehash() which could corrupt
lists because of concurrent udp_sk(sk)->udp_portaddr_hash accesses.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-08-27 13:56:21 +01:00
Edward Hyunkoo Jee
f65e2502f8 inet: frags: fix defragmented packet's IP header for af_packet
commit 0848f6428b upstream.

When ip_frag_queue() computes positions, it assumes that the passed
sk_buff does not contain L2 headers.

However, when PACKET_FANOUT_FLAG_DEFRAG is used, IP reassembly
functions can be called on outgoing packets that contain L2 headers.

Also, IPv4 checksum is not corrected after reassembly.

Fixes: 7736d33f42 ("packet: Add pre-defragmentation support for ipv4 fanouts.")
Signed-off-by: Edward Hyunkoo Jee <edjee@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jerry Chu <hkchu@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-08-12 09:48:31 +01:00
Timo Teräs
f0663e5c19 ip_tunnel: fix ipv4 pmtu check to honor inner ip header df
commit fc24f2b209 upstream.

Frag needed should be sent only if the inner header asked
to not fragment. Currently fragmentation is broken if the
tunnel has df set, but df was not asked in the original
packet. The tunnel's df needs to be still checked to update
internally the pmtu cache.

Commit 23a3647bc4 broke it, and this commit fixes
the ipv4 df check back to the way it was.

Fixes: 23a3647bc4 ("ip_tunnels: Use skb-len to PMTU check.")
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-08-10 17:10:17 +01:00
Eric Dumazet
4742814a9e ipip: fix one sparse error
commit 252a8fbe81 upstream.

make C=2 CF=-D__CHECK_ENDIAN__ net/ipv4/ipip.o
  CHECK   net/ipv4/ipip.c
net/ipv4/ipip.c:254:27: warning: incorrect type in assignment (different base types)
net/ipv4/ipip.c:254:27:    expected restricted __be32 [addressable] [usertype] o_key
net/ipv4/ipip.c:254:27:    got restricted __be16 [addressable] [usertype] i_flags

Fixes: 3b7b514f44 ("ipip: fix a regression in ioctl")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-07-15 10:01:16 +01:00
Christoph Paasch
c55f3e3528 tcp: Do not call tcp_fastopen_reset_cipher from interrupt context
commit dfea2aa654 upstream.

tcp_fastopen_reset_cipher really cannot be called from interrupt
context. It allocates the tcp_fastopen_context with GFP_KERNEL and
calls crypto_alloc_cipher, which allocates all kind of stuff with
GFP_KERNEL.

Thus, we might sleep when the key-generation is triggered by an
incoming TFO cookie-request which would then happen in interrupt-
context, as shown by enabling CONFIG_DEBUG_ATOMIC_SLEEP:

[   36.001813] BUG: sleeping function called from invalid context at mm/slub.c:1266
[   36.003624] in_atomic(): 1, irqs_disabled(): 0, pid: 1016, name: packetdrill
[   36.004859] CPU: 1 PID: 1016 Comm: packetdrill Not tainted 4.1.0-rc7 #14
[   36.006085] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[   36.008250]  00000000000004f2 ffff88007f8838a8 ffffffff8171d53a ffff880075a084a8
[   36.009630]  ffff880075a08000 ffff88007f8838c8 ffffffff810967d3 ffff88007f883928
[   36.011076]  0000000000000000 ffff88007f8838f8 ffffffff81096892 ffff88007f89be00
[   36.012494] Call Trace:
[   36.012953]  <IRQ>  [<ffffffff8171d53a>] dump_stack+0x4f/0x6d
[   36.014085]  [<ffffffff810967d3>] ___might_sleep+0x103/0x170
[   36.015117]  [<ffffffff81096892>] __might_sleep+0x52/0x90
[   36.016117]  [<ffffffff8118e887>] kmem_cache_alloc_trace+0x47/0x190
[   36.017266]  [<ffffffff81680d82>] ? tcp_fastopen_reset_cipher+0x42/0x130
[   36.018485]  [<ffffffff81680d82>] tcp_fastopen_reset_cipher+0x42/0x130
[   36.019679]  [<ffffffff81680f01>] tcp_fastopen_init_key_once+0x61/0x70
[   36.020884]  [<ffffffff81680f2c>] __tcp_fastopen_cookie_gen+0x1c/0x60
[   36.022058]  [<ffffffff816814ff>] tcp_try_fastopen+0x58f/0x730
[   36.023118]  [<ffffffff81671788>] tcp_conn_request+0x3e8/0x7b0
[   36.024185]  [<ffffffff810e3872>] ? __module_text_address+0x12/0x60
[   36.025327]  [<ffffffff8167b2e1>] tcp_v4_conn_request+0x51/0x60
[   36.026410]  [<ffffffff816727e0>] tcp_rcv_state_process+0x190/0xda0
[   36.027556]  [<ffffffff81661f97>] ? __inet_lookup_established+0x47/0x170
[   36.028784]  [<ffffffff8167c2ad>] tcp_v4_do_rcv+0x16d/0x3d0
[   36.029832]  [<ffffffff812e6806>] ? security_sock_rcv_skb+0x16/0x20
[   36.030936]  [<ffffffff8167cc8a>] tcp_v4_rcv+0x77a/0x7b0
[   36.031875]  [<ffffffff816af8c3>] ? iptable_filter_hook+0x33/0x70
[   36.032953]  [<ffffffff81657d22>] ip_local_deliver_finish+0x92/0x1f0
[   36.034065]  [<ffffffff81657f1a>] ip_local_deliver+0x9a/0xb0
[   36.035069]  [<ffffffff81657c90>] ? ip_rcv+0x3d0/0x3d0
[   36.035963]  [<ffffffff81657569>] ip_rcv_finish+0x119/0x330
[   36.036950]  [<ffffffff81657ba7>] ip_rcv+0x2e7/0x3d0
[   36.037847]  [<ffffffff81610652>] __netif_receive_skb_core+0x552/0x930
[   36.038994]  [<ffffffff81610a57>] __netif_receive_skb+0x27/0x70
[   36.040033]  [<ffffffff81610b72>] process_backlog+0xd2/0x1f0
[   36.041025]  [<ffffffff81611482>] net_rx_action+0x122/0x310
[   36.042007]  [<ffffffff81076743>] __do_softirq+0x103/0x2f0
[   36.042978]  [<ffffffff81723e3c>] do_softirq_own_stack+0x1c/0x30

This patch moves the call to tcp_fastopen_init_key_once to the places
where a listener socket creates its TFO-state, which always happens in
user-context (either from the setsockopt, or implicitly during the
listen()-call)

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Fixes: 222e83d2e0 ("tcp: switch tcp_fastopen key generation to net_get_random_once")
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-07-06 10:28:56 +01:00
Shawn Bohrer
f9f1fe3a4e ipv4/udp: Verify multicast group is ours in upd_v4_early_demux()
commit 6e54030932 upstream.

421b3885bf "udp: ipv4: Add udp early
demux" introduced a regression that allowed sockets bound to INADDR_ANY
to receive packets from multicast groups that the socket had not joined.
For example a socket that had joined 224.168.2.9 could also receive
packets from 225.168.2.9 despite not having joined that group if
ip_early_demux is enabled.

Fix this by calling ip_check_mc_rcu() in udp_v4_early_demux() to verify
that the multicast packet is indeed ours.

Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Reported-by: Yurij M. Plotnikov <Yurij.Plotnikov@oktetlabs.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-06-12 13:37:54 +01:00
Eric Dumazet
95ffa33e3c udp: fix behavior of wrong checksums
commit beb39db59d upstream.

We have two problems in UDP stack related to bogus checksums :

1) We return -EAGAIN to application even if receive queue is not empty.
   This breaks applications using edge trigger epoll()

2) Under UDP flood, we can loop forever without yielding to other
   processes, potentially hanging the host, especially on non SMP.

This patch is an attempt to make things better.

We might in the future add extra support for rt applications
wanting to better control time spent doing a recv() in a hostile
environment. For example we could validate checksums before queuing
packets in socket receive queue.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-06-12 13:35:35 +01:00
Eric W. Biederman
9ccba705cd ipv4: Avoid crashing in ip_error
commit 381c759d99 upstream.

ip_error does not check if in_dev is NULL before dereferencing it.

IThe following sequence of calls is possible:
CPU A                          CPU B
ip_rcv_finish
    ip_route_input_noref()
        ip_route_input_slow()
                               inetdev_destroy()
    dst_input()

With the result that a network device can be destroyed while processing
an input packet.

A crash was triggered with only unicast packets in flight, and
forwarding enabled on the only network device.   The error condition
was created by the removal of the network device.

As such it is likely the that error code was -EHOSTUNREACH, and the
action taken by ip_error (if in_dev had been accessible) would have
been to not increment any counters and to have tried and likely failed
to send an icmp error as the network device is going away.

Therefore handle this weird case by just dropping the packet if
!in_dev.  It will result in dropping the packet sooner, and will not
result in an actual change of behavior.

Fixes: 251da41301 ("ipv4: Cache ip_error() routes even when not forwarding.")
Reported-by: Vittorio Gambaletta <linuxbugs@vittgam.net>
Tested-by: Vittorio Gambaletta <linuxbugs@vittgam.net>
Signed-off-by: Vittorio Gambaletta <linuxbugs@vittgam.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-06-02 13:02:47 +01:00
Florent Fourcot
34aaa106fa tcp/ipv6: fix flow label setting in TIME_WAIT state
commit 21858cd02d upstream.

commit 1d13a96c74 ("ipv6: tcp: fix flowlabel value in ACK messages
send from TIME_WAIT") added the flow label in the last TCP packets.
Unfortunately, it was not casted properly.

This patch replace the buggy shift with be32_to_cpu/cpu_to_be32.

Fixes: 1d13a96c74 ("ipv6: tcp: fix flowlabel value in ACK messages")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-06-02 13:00:40 +01:00