Commit Graph

5914 Commits

Author SHA1 Message Date
Eric Dumazet 3d23401283 inet: frags: fix ip6frag_low_thresh boundary
Giving an integer to proc_doulongvec_minmax() is dangerous on 64bit arches,
since linker might place next to it a non zero value preventing a change
to ip6frag_low_thresh.

ip6frag_low_thresh is not used anymore in the kernel, but we do not
want to prematuraly break user scripts wanting to change it.

Since specifying a minimal value of 0 for proc_doulongvec_minmax()
is moot, let's remove these zero values in all defrag units.

Fixes: 6e00f7dd5e ("ipv6: frags: fix /proc/sys/net/ipv6/ip6frag_low_thresh")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-04 12:04:59 -04:00
Paolo Abeni 9e8445a56c net: avoid unneeded atomic operation in ip*_append_data()
After commit 694aba690d ("ipv4: factorize sk_wmem_alloc updates
done by __ip_append_data()") and commit 1f4c6eb240 ("ipv6:
factorize sk_wmem_alloc updates done by __ip6_append_data()"),
when transmitting sub MTU datagram, an addtional, unneeded atomic
operation is performed in ip*_append_data() to update wmem_alloc:
in the above condition the delta is 0.

The above cause small but measurable performance regression in UDP
xmit tput test with packet size below MTU.

This change avoids such overhead updating wmem_alloc only if
wmem_alloc_delta is non zero.

The error path is left intentionally unmodified: it's a slow path
and simplicity is preferred to performances.

Fixes: 694aba690d ("ipv4: factorize sk_wmem_alloc updates done by __ip_append_data()")
Fixes: 1f4c6eb240 ("ipv6: factorize sk_wmem_alloc updates done by __ip6_append_data()")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-04 11:53:08 -04:00
Alexey Kodanev 4f858c56bd ipv6: udp: set dst cache for a connected sk if current not valid
A new RTF_CACHE route can be created between ip6_sk_dst_lookup_flow()
and ip6_dst_store() calls in udpv6_sendmsg(), when datagram sending
results to ICMPV6_PKT_TOOBIG error:

    udp_v6_send_skb(), for example with vti6 tunnel:
        vti6_xmit(), get ICMPV6_PKT_TOOBIG error
            skb_dst_update_pmtu(), can create a RTF_CACHE clone
            icmpv6_send()
    ...
    udpv6_err()
        ip6_sk_update_pmtu()
           ip6_update_pmtu(), can create a RTF_CACHE clone
           ...
           ip6_datagram_dst_update()
                ip6_dst_store()

And after commit 33c162a980 ("ipv6: datagram: Update dst cache of
a connected datagram sk during pmtu update"), the UDPv6 error handler
can update socket's dst cache, but it can happen before the update in
the end of udpv6_sendmsg(), preventing getting the new dst cache on
the next udpv6_sendmsg() calls.

In order to fix it, save dst in a connected socket only if the current
socket's dst cache is invalid.

The previous patch prepared ip6_sk_dst_lookup_flow() to do that with
the new argument, and this patch enables it in udpv6_sendmsg().

Fixes: 33c162a980 ("ipv6: datagram: Update dst cache of a connected datagram sk during pmtu update")
Fixes: 45e4fd2668 ("ipv6: Only create RTF_CACHE routes after encountering pmtu exception")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-04 11:31:57 -04:00
Alexey Kodanev 9f542f616c ipv6: udp: convert 'connected' to bool type in udpv6_sendmsg()
This should make it consistent with ip6_sk_dst_lookup_flow()
that is accepting the new 'connected' parameter of type bool.

Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-04 11:31:57 -04:00
Alexey Kodanev 96818159c3 ipv6: allow to cache dst for a connected sk in ip6_sk_dst_lookup_flow()
Add 'connected' parameter to ip6_sk_dst_lookup_flow() and update
the cache only if ip6_sk_dst_check() returns NULL and a socket
is connected.

The function is used as before, the new behavior for UDP sockets
in udpv6_sendmsg() will be enabled in the next patch.

Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-04 11:31:57 -04:00
Alexey Kodanev 7d6850f7c6 ipv6: add a wrapper for ip6_dst_store() with flowi6 checks
Move commonly used pattern of ip6_dst_store() usage to a separate
function - ip6_sk_dst_store_flow(), which will check the addresses
for equality using the flow information, before saving them.

There is no functional changes in this patch. In addition, it will
be used in the next patch, in ip6_sk_dst_lookup_flow().

Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-04 11:31:57 -04:00
Eric Dumazet 6e00f7dd5e ipv6: frags: fix /proc/sys/net/ipv6/ip6frag_low_thresh
I forgot to change ip6frag_low_thresh proc_handler
from proc_dointvec_minmax to proc_doulongvec_minmax

Fixes: 3e67f106f6 ("inet: frags: break the 2GB limit for frags storage")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-02 10:10:50 -04:00
David S. Miller c0b458a946 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Minor conflicts in drivers/net/ethernet/mellanox/mlx5/core/en_rep.c,
we had some overlapping changes:

1) In 'net' MLX5E_PARAMS_LOG_{SQ,RQ}_SIZE -->
   MLX5E_REP_PARAMS_LOG_{SQ,RQ}_SIZE

2) In 'net-next' params->log_rq_size is renamed to be
   params->log_rq_mtu_frames.

3) In 'net-next' params->hard_mtu is added.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-01 19:49:34 -04:00
Eric Dumazet 1f4c6eb240 ipv6: factorize sk_wmem_alloc updates done by __ip6_append_data()
While testing my inet defrag changes, I found that the senders
could spend ~20% of cpu cycles in skb_set_owner_w() updating
sk->sk_wmem_alloc for every fragment they cook, competing
with TX completion of prior skbs possibly happening on another cpus.

The solution to this problem is to use alloc_skb() instead
of sock_wmalloc() and manually perform a single sk_wmem_alloc change.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-01 14:08:21 -04:00
Alexey Kodanev ec1258903a ip6_gre: remove redundant 'tunnel' setting in ip6erspan_tap_init()
'tunnel' was already set at the start of ip6erspan_tap_init().

Fixes: 5a963eb61b ("ip6_gre: Add ERSPAN native tunnel support")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-01 14:02:32 -04:00
David S. Miller d4069fe6fc Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-03-31

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add raw BPF tracepoint API in order to have a BPF program type that
   can access kernel internal arguments of the tracepoints in their
   raw form similar to kprobes based BPF programs. This infrastructure
   also adds a new BPF_RAW_TRACEPOINT_OPEN command to BPF syscall which
   returns an anon-inode backed fd for the tracepoint object that allows
   for automatic detach of the BPF program resp. unregistering of the
   tracepoint probe on fd release, from Alexei.

2) Add new BPF cgroup hooks at bind() and connect() entry in order to
   allow BPF programs to reject, inspect or modify user space passed
   struct sockaddr, and as well a hook at post bind time once the port
   has been allocated. They are used in FB's container management engine
   for implementing policy, replacing fragile LD_PRELOAD wrapper
   intercepting bind() and connect() calls that only works in limited
   scenarios like glibc based apps but not for other runtimes in
   containerized applications, from Andrey.

3) BPF_F_INGRESS flag support has been added to sockmap programs for
   their redirect helper call bringing it in line with cls_bpf based
   programs. Support is added for both variants of sockmap programs,
   meaning for tx ULP hooks as well as recv skb hooks, from John.

4) Various improvements on BPF side for the nfp driver, besides others
   this work adds BPF map update and delete helper call support from
   the datapath, JITing of 32 and 64 bit XADD instructions as well as
   offload support of bpf_get_prandom_u32() call. Initial implementation
   of nfp packet cache has been tackled that optimizes memory access
   (see merge commit for further details), from Jakub and Jiong.

5) Removal of struct bpf_verifier_env argument from the print_bpf_insn()
   API has been done in order to prepare to use print_bpf_insn() soon
   out of perf tool directly. This makes the print_bpf_insn() API more
   generic and pushes the env into private data. bpftool is adjusted
   as well with the print_bpf_insn() argument removal, from Jiri.

6) Couple of cleanups and prep work for the upcoming BTF (BPF Type
   Format). The latter will reuse the current BPF verifier log as
   well, thus bpf_verifier_log() is further generalized, from Martin.

7) For bpf_getsockopt() and bpf_setsockopt() helpers, IPv4 IP_TOS read
   and write support has been added in similar fashion to existing
   IPv6 IPV6_TCLASS socket option we already have, from Nikita.

8) Fixes in recent sockmap scatterlist API usage, which did not use
   sg_init_table() for initialization thus triggering a BUG_ON() in
   scatterlist API when CONFIG_DEBUG_SG was enabled. This adds and
   uses a small helper sg_init_marker() to properly handle the affected
   cases, from Prashant.

9) Let the BPF core follow IDR code convention and therefore use the
   idr_preload() and idr_preload_end() helpers, which would also help
   idr_alloc_cyclic() under GFP_ATOMIC to better succeed under memory
   pressure, from Shaohua.

10) Last but not least, a spelling fix in an error message for the
    BPF cookie UID helper under BPF sample code, from Colin.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31 23:33:04 -04:00
Eric Dumazet f2d1c724fc inet: frags: get rid of nf_ct_frag6_skb_cb/NFCT_FRAG6_CB
nf_ct_frag6_queue() uses skb->cb[] to store the fragment offset,
meaning that we could use two cache lines per skb when finding
the insertion point, if for some reason inet6_skb_parm size
is increased in the future.

By using skb->ip_defrag_offset instead of skb->cb[] we pack all the fields
in a single cache line, matching what we did for IPv4.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31 23:25:40 -04:00
Eric Dumazet 219badfaad ipv6: frags: get rid of ip6frag_skb_cb/FRAG6_CB
ip6_frag_queue uses skb->cb[] to store the fragment offset, meaning that
we could use two cache lines per skb when finding the insertion point,
if for some reason inet6_skb_parm size is increased in the future.

By using skb->ip_defrag_offset instead of skb->cb[], we pack all
the fields in a single cache line, matching what we did for IPv4.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31 23:25:40 -04:00
Eric Dumazet 05c0b86b96 ipv6: frags: rewrite ip6_expire_frag_queue()
Make it similar to IPv4 ip_expire(), and release the lock
before calling icmp functions.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31 23:25:39 -04:00
Eric Dumazet 3e67f106f6 inet: frags: break the 2GB limit for frags storage
Some users are willing to provision huge amounts of memory to be able
to perform reassembly reasonnably well under pressure.

Current memory tracking is using one atomic_t and integers.

Switch to atomic_long_t so that 64bit arches can use more than 2GB,
without any cost for 32bit arches.

Note that this patch avoids an overflow error, if high_thresh was set
to ~2GB, since this test in inet_frag_alloc() was never true :

if (... || frag_mem_limit(nf) > nf->high_thresh)

Tested:

$ echo 16000000000 >/proc/sys/net/ipv4/ipfrag_high_thresh

<frag DDOS>

$ grep FRAG /proc/net/sockstat
FRAG: inuse 14705885 memory 16000002880

$ nstat -n ; sleep 1 ; nstat | grep Reas
IpReasmReqds                    3317150            0.0
IpReasmFails                    3317112            0.0

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31 23:25:39 -04:00
Eric Dumazet 2d44ed22e6 inet: frags: remove inet_frag_maybe_warn_overflow()
This function is obsolete, after rhashtable addition to inet defrag.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31 23:25:39 -04:00
Eric Dumazet 399d1404be inet: frags: get rif of inet_frag_evicting()
This refactors ip_expire() since one indentation level is removed.

Note: in the future, we should try hard to avoid the skb_clone()
since this is a serious performance cost.
Under DDOS, the ICMP message wont be sent because of rate limits.

Fact that ip6_expire_frag_queue() does not use skb_clone() is
disturbing too. Presumably IPv6 should have the same
issue than the one we fixed in commit ec4fbd6475
("inet: frag: release spinlock before calling icmp_send()")

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31 23:25:39 -04:00
Eric Dumazet 6befe4a78b inet: frags: remove some helpers
Remove sum_frag_mem_limit(), ip_frag_mem() & ip6_frag_mem()

Also since we use rhashtable we can bring back the number of fragments
in "grep FRAG /proc/net/sockstat /proc/net/sockstat6" that was
removed in commit 434d305405 ("inet: frag: don't account number
of fragment queues")

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31 23:25:39 -04:00
Eric Dumazet 648700f76b inet: frags: use rhashtables for reassembly units
Some applications still rely on IP fragmentation, and to be fair linux
reassembly unit is not working under any serious load.

It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!)

A work queue is supposed to garbage collect items when host is under memory
pressure, and doing a hash rebuild, changing seed used in hash computations.

This work queue blocks softirqs for up to 25 ms when doing a hash rebuild,
occurring every 5 seconds if host is under fire.

Then there is the problem of sharing this hash table for all netns.

It is time to switch to rhashtables, and allocate one of them per netns
to speedup netns dismantle, since this is a critical metric these days.

Lookup is now using RCU. A followup patch will even remove
the refcount hold/release left from prior implementation and save
a couple of atomic operations.

Before this patch, 16 cpus (16 RX queue NIC) could not handle more
than 1 Mpps frags DDOS.

After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB
of storage for the fragments (exact number depends on frags being evicted
after timeout)

$ grep FRAG /proc/net/sockstat
FRAG: inuse 1966916 memory 2140004608

A followup patch will change the limits for 64bit arches.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Florian Westphal <fw@strlen.de>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Alexander Aring <alex.aring@gmail.com>
Cc: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31 23:25:39 -04:00
Eric Dumazet 5b975bab23 inet: frags: refactor ipv6_frag_init()
We want to call inet_frags_init() earlier.

This is a prereq to "inet: frags: use rhashtables for reassembly units"

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31 23:25:38 -04:00
Eric Dumazet 093ba72914 inet: frags: add a pointer to struct netns_frags
In order to simplify the API, add a pointer to struct inet_frags.
This will allow us to make things less complex.

These functions no longer have a struct inet_frags parameter :

inet_frag_destroy(struct inet_frag_queue *q  /*, struct inet_frags *f */)
inet_frag_put(struct inet_frag_queue *q /*, struct inet_frags *f */)
inet_frag_kill(struct inet_frag_queue *q /*, struct inet_frags *f */)
inet_frags_exit_net(struct netns_frags *nf /*, struct inet_frags *f */)
ip6_expire_frag_queue(struct net *net, struct frag_queue *fq)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31 23:25:38 -04:00
Eric Dumazet 787bea7748 inet: frags: change inet_frags_init_net() return value
We will soon initialize one rhashtable per struct netns_frags
in inet_frags_init_net().

This patch changes the return value to eventually propagate an
error.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31 23:25:38 -04:00
Andrey Ignatov aac3fc320d bpf: Post-hooks for sys_bind
"Post-hooks" are hooks that are called right before returning from
sys_bind. At this time IP and port are already allocated and no further
changes to `struct sock` can happen before returning from sys_bind but
BPF program has a chance to inspect the socket and change sys_bind
result.

Specifically it can e.g. inspect what port was allocated and if it
doesn't satisfy some policy, BPF program can force sys_bind to fail and
return EPERM to user.

Another example of usage is recording the IP:port pair to some map to
use it in later calls to sys_connect. E.g. if some TCP server inside
cgroup was bound to some IP:port_n, it can be recorded to a map. And
later when some TCP client inside same cgroup is trying to connect to
127.0.0.1:port_n, BPF hook for sys_connect can override the destination
and connect application to IP:port_n instead of 127.0.0.1:port_n. That
helps forcing all applications inside a cgroup to use desired IP and not
break those applications if they e.g. use localhost to communicate
between each other.

== Implementation details ==

Post-hooks are implemented as two new attach types
`BPF_CGROUP_INET4_POST_BIND` and `BPF_CGROUP_INET6_POST_BIND` for
existing prog type `BPF_PROG_TYPE_CGROUP_SOCK`.

Separate attach types for IPv4 and IPv6 are introduced to avoid access
to IPv6 field in `struct sock` from `inet_bind()` and to IPv4 field from
`inet6_bind()` since those fields might not make sense in such cases.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-31 02:16:26 +02:00
Andrey Ignatov d74bad4e74 bpf: Hooks for sys_connect
== The problem ==

See description of the problem in the initial patch of this patch set.

== The solution ==

The patch provides much more reliable in-kernel solution for the 2nd
part of the problem: making outgoing connecttion from desired IP.

It adds new attach types `BPF_CGROUP_INET4_CONNECT` and
`BPF_CGROUP_INET6_CONNECT` for program type
`BPF_PROG_TYPE_CGROUP_SOCK_ADDR` that can be used to override both
source and destination of a connection at connect(2) time.

Local end of connection can be bound to desired IP using newly
introduced BPF-helper `bpf_bind()`. It allows to bind to only IP though,
and doesn't support binding to port, i.e. leverages
`IP_BIND_ADDRESS_NO_PORT` socket option. There are two reasons for this:
* looking for a free port is expensive and can affect performance
  significantly;
* there is no use-case for port.

As for remote end (`struct sockaddr *` passed by user), both parts of it
can be overridden, remote IP and remote port. It's useful if an
application inside cgroup wants to connect to another application inside
same cgroup or to itself, but knows nothing about IP assigned to the
cgroup.

Support is added for IPv4 and IPv6, for TCP and UDP.

IPv4 and IPv6 have separate attach types for same reason as sys_bind
hooks, i.e. to prevent reading from / writing to e.g. user_ip6 fields
when user passes sockaddr_in since it'd be out-of-bound.

== Implementation notes ==

The patch introduces new field in `struct proto`: `pre_connect` that is
a pointer to a function with same signature as `connect` but is called
before it. The reason is in some cases BPF hooks should be called way
before control is passed to `sk->sk_prot->connect`. Specifically
`inet_dgram_connect` autobinds socket before calling
`sk->sk_prot->connect` and there is no way to call `bpf_bind()` from
hooks from e.g. `ip4_datagram_connect` or `ip6_datagram_connect` since
it'd cause double-bind. On the other hand `proto.pre_connect` provides a
flexible way to add BPF hooks for connect only for necessary `proto` and
call them at desired time before `connect`. Since `bpf_bind()` is
allowed to bind only to IP and autobind in `inet_dgram_connect` binds
only port there is no chance of double-bind.

bpf_bind() sets `force_bind_address_no_port` to bind to only IP despite
of value of `bind_address_no_port` socket field.

bpf_bind() sets `with_lock` to `false` when calling to __inet_bind()
and __inet6_bind() since all call-sites, where bpf_bind() is called,
already hold socket lock.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-31 02:15:54 +02:00
Andrey Ignatov 3679d585bb net: Introduce __inet_bind() and __inet6_bind
Refactor `bind()` code to make it ready to be called from BPF helper
function `bpf_bind()` (will be added soon). Implementation of
`inet_bind()` and `inet6_bind()` is separated into `__inet_bind()` and
`__inet6_bind()` correspondingly. These function can be used from both
`sk_prot->bind` and `bpf_bind()` contexts.

New functions have two additional arguments.

`force_bind_address_no_port` forces binding to IP only w/o checking
`inet_sock.bind_address_no_port` field. It'll allow to bind local end of
a connection to desired IP in `bpf_bind()` w/o changing
`bind_address_no_port` field of a socket. It's useful since `bpf_bind()`
can return an error and we'd need to restore original value of
`bind_address_no_port` in that case if we changed this before calling to
the helper.

`with_lock` specifies whether to lock socket when working with `struct
sk` or not. The argument is set to `true` for `sk_prot->bind`, i.e. old
behavior is preserved. But it will be set to `false` for `bpf_bind()`
use-case. The reason is all call-sites, where `bpf_bind()` will be
called, already hold that socket lock.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-31 02:15:43 +02:00
Andrey Ignatov 4fbac77d2d bpf: Hooks for sys_bind
== The problem ==

There is a use-case when all processes inside a cgroup should use one
single IP address on a host that has multiple IP configured.  Those
processes should use the IP for both ingress and egress, for TCP and UDP
traffic. So TCP/UDP servers should be bound to that IP to accept
incoming connections on it, and TCP/UDP clients should make outgoing
connections from that IP. It should not require changing application
code since it's often not possible.

Currently it's solved by intercepting glibc wrappers around syscalls
such as `bind(2)` and `connect(2)`. It's done by a shared library that
is preloaded for every process in a cgroup so that whenever TCP/UDP
server calls `bind(2)`, the library replaces IP in sockaddr before
passing arguments to syscall. When application calls `connect(2)` the
library transparently binds the local end of connection to that IP
(`bind(2)` with `IP_BIND_ADDRESS_NO_PORT` to avoid performance penalty).

Shared library approach is fragile though, e.g.:
* some applications clear env vars (incl. `LD_PRELOAD`);
* `/etc/ld.so.preload` doesn't help since some applications are linked
  with option `-z nodefaultlib`;
* other applications don't use glibc and there is nothing to intercept.

== The solution ==

The patch provides much more reliable in-kernel solution for the 1st
part of the problem: binding TCP/UDP servers on desired IP. It does not
depend on application environment and implementation details (whether
glibc is used or not).

It adds new eBPF program type `BPF_PROG_TYPE_CGROUP_SOCK_ADDR` and
attach types `BPF_CGROUP_INET4_BIND` and `BPF_CGROUP_INET6_BIND`
(similar to already existing `BPF_CGROUP_INET_SOCK_CREATE`).

The new program type is intended to be used with sockets (`struct sock`)
in a cgroup and provided by user `struct sockaddr`. Pointers to both of
them are parts of the context passed to programs of newly added types.

The new attach types provides hooks in `bind(2)` system call for both
IPv4 and IPv6 so that one can write a program to override IP addresses
and ports user program tries to bind to and apply such a program for
whole cgroup.

== Implementation notes ==

[1]
Separate attach types for `AF_INET` and `AF_INET6` are added
intentionally to prevent reading/writing to offsets that don't make
sense for corresponding socket family. E.g. if user passes `sockaddr_in`
it doesn't make sense to read from / write to `user_ip6[]` context
fields.

[2]
The write access to `struct bpf_sock_addr_kern` is implemented using
special field as an additional "register".

There are just two registers in `sock_addr_convert_ctx_access`: `src`
with value to write and `dst` with pointer to context that can't be
changed not to break later instructions. But the fields, allowed to
write to, are not available directly and to access them address of
corresponding pointer has to be loaded first. To get additional register
the 1st not used by `src` and `dst` one is taken, its content is saved
to `bpf_sock_addr_kern.tmp_reg`, then the register is used to load
address of pointer field, and finally the register's content is restored
from the temporary field after writing `src` value.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-31 02:15:18 +02:00
David Ahern b6cdbc8523 net/ipv6: Fix route leaking between VRFs
Donald reported that IPv6 route leaking between VRFs is not working.
The root cause is the strict argument in the call to rt6_lookup when
validating the nexthop spec.

ip6_route_check_nh validates the gateway and device (if given) of a
route spec. It in turn could call rt6_lookup (e.g., lookup in a given
table did not succeed so it falls back to a full lookup) and if so
sets the strict argument to 1. That means if the egress device is given,
the route lookup needs to return a result with the same device. This
strict requirement does not work with VRFs (IPv4 or IPv6) because the
oif in the flow struct is overridden with the index of the VRF device
to trigger a match on the l3mdev rule and force the lookup to its table.

The right long term solution is to add an l3mdev index to the flow
struct such that the oif is not overridden. That solution will not
backport well, so this patch aims for a simpler solution to relax the
strict argument if the route spec device is an l3mdev slave. As done
in other places, use the FLOWI_FLAG_SKIP_NH_OIF to know that the
RT6_LOOKUP_F_IFACE flag needs to be removed.

Fixes: ca254490c8 ("net: Add VRF support to IPv6 stack")
Reported-by: Donald Sharp <sharpd@cumulusnetworks.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-30 14:23:59 -04:00
David Lebrun 5807b22c91 ipv6: sr: fix seg6 encap performances with TSO enabled
Enabling TSO can lead to abysmal performances when using seg6 in
encap mode, such as with the ixgbe driver. This patch adds a call to
iptunnel_handle_offloads() to remove the encapsulation bit if needed.

Before:
root@comp4-seg6bpf:~# iperf3 -c fc00::55
Connecting to host fc00::55, port 5201
[  4] local fc45::4 port 36592 connected to fc00::55 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec   196 KBytes  1.60 Mbits/sec   47   6.66 KBytes
[  4]   1.00-2.00   sec   304 KBytes  2.49 Mbits/sec  100   5.33 KBytes
[  4]   2.00-3.00   sec   284 KBytes  2.32 Mbits/sec   92   5.33 KBytes

After:
root@comp4-seg6bpf:~# iperf3 -c fc00::55
Connecting to host fc00::55, port 5201
[  4] local fc45::4 port 43062 connected to fc00::55 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec  1.03 GBytes  8.89 Gbits/sec    0    743 KBytes
[  4]   1.00-2.00   sec  1.03 GBytes  8.87 Gbits/sec    0    743 KBytes
[  4]   2.00-3.00   sec  1.03 GBytes  8.87 Gbits/sec    0    743 KBytes

Reported-by: Tom Herbert <tom@quantonium.net>
Fixes: 6c8702c60b ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Signed-off-by: David Lebrun <dlebrun@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-30 14:14:33 -04:00
Lorenzo Bianconi 428604fb11 ipv6: do not set routes if disable_ipv6 has been enabled
Do not allow setting ipv6 routes from userspace if disable_ipv6 has been
enabled. The issue can be triggered using the following reproducer:

- sysctl net.ipv6.conf.all.disable_ipv6=1
- ip -6 route add a🅱️c:d::/64 dev em1
- ip -6 route show
  a🅱️c:d::/64 dev em1 metric 1024 pref medium

Fix it checking disable_ipv6 value in ip6_route_info_create routine

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-30 12:20:52 -04:00
David S. Miller d162190bde Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

The following patchset contains Netfilter/IPVS updates for your net-next
tree. This batch comes with more input sanitization for xtables to
address bug reports from fuzzers, preparation works to the flowtable
infrastructure and assorted updates. In no particular order, they are:

1) Make sure userspace provides a valid standard target verdict, from
   Florian Westphal.

2) Sanitize error target size, also from Florian.

3) Validate that last rule in basechain matches underflow/policy since
   userspace assumes this when decoding the ruleset blob that comes
   from the kernel, from Florian.

4) Consolidate hook entry checks through xt_check_table_hooks(),
   patch from Florian.

5) Cap ruleset allocations at 512 mbytes, 134217728 rules and reject
   very large compat offset arrays, so we have a reasonable upper limit
   and fuzzers don't exercise the oom-killer. Patches from Florian.

6) Several WARN_ON checks on xtables mutex helper, from Florian.

7) xt_rateest now has a hashtable per net, from Cong Wang.

8) Consolidate counter allocation in xt_counters_alloc(), from Florian.

9) Earlier xt_table_unlock() call in {ip,ip6,arp,eb}tables, patch
   from Xin Long.

10) Set FLOW_OFFLOAD_DIR_* to IP_CT_DIR_* definitions, patch from
    Felix Fietkau.

11) Consolidate code through flow_offload_fill_dir(), also from Felix.

12) Inline ip6_dst_mtu_forward() just like ip_dst_mtu_maybe_forward()
    to remove a dependency with flowtable and ipv6.ko, from Felix.

13) Cache mtu size in flow_offload_tuple object, this is safe for
    forwarding as f87c10a8aa describes, from Felix.

14) Rename nf_flow_table.c to nf_flow_table_core.o, to simplify too
    modular infrastructure, from Felix.

15) Add rt0, rt2 and rt4 IPv6 routing extension support, patch from
    Ahmed Abdelsalam.

16) Remove unused parameter in nf_conncount_count(), from Yi-Hung Wei.

17) Support for counting only to nf_conncount infrastructure, patch
    from Yi-Hung Wei.

18) Add strict NFT_CT_{SRC_IP,DST_IP,SRC_IP6,DST_IP6} key datatypes
    to nft_ct.

19) Use boolean as return value from ipt_ah and from IPVS too, patch
    from Gustavo A. R. Silva.

20) Remove useless parameters in nfnl_acct_overquota() and
    nf_conntrack_broadcast_help(), from Taehee Yoo.

21) Use ipv6_addr_is_multicast() from xt_cluster, also from Taehee Yoo.

22) Statify nf_tables_obj_lookup_byhandle, patch from Fengguang Wu.

23) Fix typo in xt_limit, from Geert Uytterhoeven.

24) Do no use VLAs in Netfilter code, again from Gustavo.

25) Use ADD_COUNTER from ebtables, from Taehee Yoo.

26) Bitshift support for CONNMARK and MARK targets, from Jack Ma.

27) Use pr_*() and add pr_fmt(), from Arushi Singhal.

28) Add synproxy support to ctnetlink.

29) ICMP type and IGMP matching support for ebtables, patches from
    Matthias Schiffer.

30) Support for the revision infrastructure to ebtables, from
    Bernie Harris.

31) String match support for ebtables, also from Bernie.

32) Documentation for the new flowtable infrastructure.

33) Use generic comparison functions in ebt_stp, from Joe Perches.

34) Demodularize filter chains in nftables.

35) Register conntrack hooks in case nftables NAT chain is added.

36) Merge assignments with return in a couple of spots in the
    Netfilter codebase, also from Arushi.

37) Document that xtables percpu counters are stored in the same
    memory area, from Ben Hutchings.

38) Revert mark_source_chains() sanity checks that break existing
    rulesets, from Florian Westphal.

39) Use is_zero_ether_addr() in the ipset codebase, from Joe Perches.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-30 11:41:18 -04:00
Florian Westphal e3b5e1ec75 Revert "netfilter: x_tables: ensure last rule in base chain matches underflow/policy"
This reverts commit 0d7df906a0.

Valdis Kletnieks reported that xtables is broken in linux-next since
0d7df906a0  ("netfilter: x_tables: ensure last rule in base chain
matches underflow/policy"), as kernel rejects the (well-formed) ruleset:

[   64.402790] ip6_tables: last base chain position 1136 doesn't match underflow 1344 (hook 1)

mark_source_chains is not the correct place for such a check, as it
terminates evaluation of a chain once it sees an unconditional verdict
(following rules are known to be unreachable). It seems preferrable to
fix libiptc instead, so remove this check again.

Fixes: 0d7df906a0 ("netfilter: x_tables: ensure last rule in base chain matches underflow/policy")
Reported-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-03-30 12:20:32 +02:00
Pablo Neira Ayuso 43a605f2f7 netfilter: nf_tables: enable conntrack if NAT chain is registered
Register conntrack hooks if the user adds NAT chains. Users get confused
with the existing behaviour since they will see no packets hitting this
chain until they add the first rule that refers to conntrack.

This patch adds new ->init() and ->free() indirections to chain types
that can be used by NAT chains to invoke the conntrack dependency.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-03-30 11:29:19 +02:00
Pablo Neira Ayuso 02c7b25e5f netfilter: nf_tables: build-in filter chain type
One module per supported filter chain family type takes too much memory
for very little code - too much modularization - place all chain filter
definitions in one single file.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-03-30 11:29:19 +02:00
Pablo Neira Ayuso cc07eeb0e5 netfilter: nf_tables: nft_register_chain_type() returns void
Use WARN_ON() instead since it should not happen that neither family
goes over NFPROTO_NUMPROTO nor there is already a chain of this type
already registered.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-03-30 11:29:18 +02:00
Pablo Neira Ayuso 32537e9184 netfilter: nf_tables: rename struct nf_chain_type
Use nft_ prefix. By when I added chain types, I forgot to use the
nftables prefix. Rename enum nft_chain_type to enum nft_chain_types too,
otherwise there is an overlap.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-03-30 11:29:17 +02:00
Eric Dumazet 18dcbe12fe ipv6: export ip6 fragments sysctl to unprivileged users
IPv4 was changed in commit 52a773d645 ("net: Export ip fragment
sysctl to unprivileged users")

The only sysctl that is not per-netns is not used :
ip6frag_secret_interval

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-29 14:14:03 -04:00
David Ahern 2233000cba net/ipv6: Move call_fib6_entry_notifiers up for route adds
Move call to call_fib6_entry_notifiers for new IPv6 routes to right
before the insertion into the FIB. At this point notifier handlers can
decide the fate of the new route with a clean path to delete the
potential new entry if the notifier returns non-0.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-29 14:10:31 -04:00
David S. Miller 56455e0998 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next
Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2018-03-29

1) Remove a redundant pointer initialization esp_input_set_header().
   From Colin Ian King.

2) Mark the xfrm kmem_caches as __ro_after_init.
   From Alexey Dobriyan.

3) Do the checksum for an ipsec offlad packet in software
   if the device does not advertise NETIF_F_HW_ESP_TX_CSUM.
   From Shannon Nelson.

4) Use booleans for true and false instead of integers
   in xfrm_policy_cache_flush().
   From Gustavo A. R. Silva

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

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-29 11:22:31 -04:00
David S. Miller 020295d95e Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec
Steffen Klassert says:

====================
pull request (net): ipsec 2018-03-29

1) Fix a rcu_read_lock/rcu_read_unlock imbalance
   in the error path of xfrm_local_error().
   From Taehee Yoo.

2) Some VTI MTU fixes. From Stefano Brivio.

3) Fix a too early overwritten skb control buffer
   on xfrm transport mode.

Please note that this pull request has a merge conflict
in net/ipv4/ip_tunnel.c.

The conflict is between

commit f6cc9c054e ("ip_tunnel: Emit events for post-register MTU changes")

from the net tree and

commit 24fc79798b ("ip_tunnel: Clamp MTU to bounds on new link")

from the ipsec tree.

It can be solved as it is currently done in linux-next.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-29 10:12:47 -04:00
Kirill Tkhai 2f635ceeb2 net: Drop pernet_operations::async
Synchronous pernet_operations are not allowed anymore.
All are asynchronous. So, drop the structure member.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27 13:18:09 -04:00
Joe Perches e32ac25018 ipv6: addrconf: Use normal debugging style
Remove local ADBG macro and use netdev_dbg/pr_debug

Miscellanea:

o Remove unnecessary debug message after allocation failure as there
  already is a dump_stack() on the failure paths
o Leave the allocation failure message on snmp6_alloc_dev as there
  is one code path that does not do a dump_stack()

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27 10:54:40 -04:00
Yuval Mintz 8c13af2a21 ip6mr: Add refcounting to mfc
Since ipmr and ip6mr are using the same mr_mfc struct at their core, we
can now refactor the ipmr_cache_{hold,put} logic and apply refcounting
to both ipmr and ip6mr.

Signed-off-by: Yuval Mintz <yuvalm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-26 13:14:43 -04:00
Yuval Mintz d3c07e5b99 ip6mr: Add API for default_rule fib
Add the ability to discern whether a given FIB rule notification relates
to the default rule inserted when registering ip6mr or a different one.

Would later be used by drivers wishing to offload ipv6 multicast routes
but unable to offload rules other than the default one.

Signed-off-by: Yuval Mintz <yuvalm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-26 13:14:43 -04:00
Yuval Mintz 088aa3eec2 ip6mr: Support fib notifications
In similar fashion to ipmr, support fib notifications for ip6mr mfc and
vif related events. This would later allow drivers to react to said
notifications and offload the IPv6 mroutes.

Signed-off-by: Yuval Mintz <yuvalm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-26 13:14:43 -04:00
Joe Perches d6444062f8 net: Use octal not symbolic permissions
Prefer the direct use of octal for permissions.

Done with checkpatch -f --types=SYMBOLIC_PERMS --fix-inplace
and some typing.

Miscellanea:

o Whitespace neatening around these conversions.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-26 12:07:48 -04:00
Paolo Abeni 10b8a3de60 ipv6: the entire IPv6 header chain must fit the first fragment
While building ipv6 datagram we currently allow arbitrary large
extheaders, even beyond pmtu size. The syzbot has found a way
to exploit the above to trigger the following splat:

kernel BUG at ./include/linux/skbuff.h:2073!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
    (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 4230 Comm: syzkaller672661 Not tainted 4.16.0-rc2+ #326
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__skb_pull include/linux/skbuff.h:2073 [inline]
RIP: 0010:__ip6_make_skb+0x1ac8/0x2190 net/ipv6/ip6_output.c:1636
RSP: 0018:ffff8801bc18f0f0 EFLAGS: 00010293
RAX: ffff8801b17400c0 RBX: 0000000000000738 RCX: ffffffff84f01828
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8801b415ac18
RBP: ffff8801bc18f360 R08: ffff8801b4576844 R09: 0000000000000000
R10: ffff8801bc18f380 R11: ffffed00367aee4e R12: 00000000000000d6
R13: ffff8801b415a740 R14: dffffc0000000000 R15: ffff8801b45767c0
FS:  0000000001535880(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000b000 CR3: 00000001b4123001 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  ip6_finish_skb include/net/ipv6.h:969 [inline]
  udp_v6_push_pending_frames+0x269/0x3b0 net/ipv6/udp.c:1073
  udpv6_sendmsg+0x2a96/0x3400 net/ipv6/udp.c:1343
  inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764
  sock_sendmsg_nosec net/socket.c:630 [inline]
  sock_sendmsg+0xca/0x110 net/socket.c:640
  ___sys_sendmsg+0x320/0x8b0 net/socket.c:2046
  __sys_sendmmsg+0x1ee/0x620 net/socket.c:2136
  SYSC_sendmmsg net/socket.c:2167 [inline]
  SyS_sendmmsg+0x35/0x60 net/socket.c:2162
  do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4404c9
RSP: 002b:00007ffdce35f948 EFLAGS: 00000217 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004404c9
RDX: 0000000000000003 RSI: 0000000020001f00 RDI: 0000000000000003
RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 0000000020000080 R11: 0000000000000217 R12: 0000000000401df0
R13: 0000000000401e80 R14: 0000000000000000 R15: 0000000000000000
Code: ff e8 1d 5e b9 fc e9 15 e9 ff ff e8 13 5e b9 fc e9 44 e8 ff ff e8 29
5e b9 fc e9 c0 e6 ff ff e8 3f f3 80 fc 0f 0b e8 38 f3 80 fc <0f> 0b 49 8d
87 80 00 00 00 4d 8d 87 84 00 00 00 48 89 85 20 fe
RIP: __skb_pull include/linux/skbuff.h:2073 [inline] RSP: ffff8801bc18f0f0
RIP: __ip6_make_skb+0x1ac8/0x2190 net/ipv6/ip6_output.c:1636 RSP:
ffff8801bc18f0f0

As stated by RFC 7112 section 5:

   When a host fragments an IPv6 datagram, it MUST include the entire
   IPv6 Header Chain in the First Fragment.

So this patch addresses the issue dropping datagrams with excessive
extheader length. It also updates the error path to report to the
calling socket nonnegative pmtu values.

The issue apparently predates git history.

v1 -> v2: cleanup error path, as per Eric's suggestion

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot+91e6f9932ff122fa4410@syzkaller.appspotmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-25 21:17:20 -04:00
Hans Wippel bc58a1baf2 net/ipv4: disable SMC TCP option with SYN Cookies
Currently, the SMC experimental TCP option in a SYN packet is lost on
the server side when SYN Cookies are active. However, the corresponding
SYNACK sent back to the client contains the SMC option. This causes an
inconsistent view of the SMC capabilities on the client and server.

This patch disables the SMC option in the SYNACK when SYN Cookies are
active to avoid this issue.

Fixes: 60e2a77807 ("tcp: TCP experimental option for SMC")
Signed-off-by: Hans Wippel <hwippel@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-25 20:53:54 -04:00
David S. Miller b9ee96b45f Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for your net tree,
they are:

1) Don't pick fixed hash implementation for NFT_SET_EVAL sets, otherwise
   userspace hits EOPNOTSUPP with valid rules using the meter statement,
   from Florian Westphal.

2) If you send a batch that flushes the existing ruleset (that contains
   a NAT chain) and the new ruleset definition comes with a new NAT
   chain, don't bogusly hit EBUSY. Also from Florian.

3) Missing netlink policy attribute validation, from Florian.

4) Detach conntrack template from skbuff if IP_NODEFRAG is set on,
   from Paolo Abeni.

5) Cache device names in flowtable object, otherwise we may end up
   walking over devices going aways given no rtnl_lock is held.

6) Fix incorrect net_device ingress with ingress hooks.

7) Fix crash when trying to read more data than available in UDP
   packets from the nf_socket infrastructure, from Subash.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-24 17:10:01 -04:00
Subash Abhinov Kasiviswanathan 32c1733f0d netfilter: nf_socket: Fix out of bounds access in nf_sk_lookup_slow_v{4,6}
skb_header_pointer will copy data into a buffer if data is non linear,
otherwise it will return a pointer in the linear section of the data.
nf_sk_lookup_slow_v{4,6} always copies data of size udphdr but later
accesses memory within the size of tcphdr (th->doff) in case of TCP
packets. This causes a crash when running with KASAN with the following
call stack -

BUG: KASAN: stack-out-of-bounds in xt_socket_lookup_slow_v4+0x524/0x718
net/netfilter/xt_socket.c:178
Read of size 2 at addr ffffffe3d417a87c by task syz-executor/28971
CPU: 2 PID: 28971 Comm: syz-executor Tainted: G    B   W  O    4.9.65+ #1
Call trace:
[<ffffff9467e8d390>] dump_backtrace+0x0/0x428 arch/arm64/kernel/traps.c:76
[<ffffff9467e8d7e0>] show_stack+0x28/0x38 arch/arm64/kernel/traps.c:226
[<ffffff946842d9b8>] __dump_stack lib/dump_stack.c:15 [inline]
[<ffffff946842d9b8>] dump_stack+0xd4/0x124 lib/dump_stack.c:51
[<ffffff946811d4b0>] print_address_description+0x68/0x258 mm/kasan/report.c:248
[<ffffff946811d8c8>] kasan_report_error mm/kasan/report.c:347 [inline]
[<ffffff946811d8c8>] kasan_report.part.2+0x228/0x2f0 mm/kasan/report.c:371
[<ffffff946811df44>] kasan_report+0x5c/0x70 mm/kasan/report.c:372
[<ffffff946811bebc>] check_memory_region_inline mm/kasan/kasan.c:308 [inline]
[<ffffff946811bebc>] __asan_load2+0x84/0x98 mm/kasan/kasan.c:739
[<ffffff94694d6f04>] __tcp_hdrlen include/linux/tcp.h:35 [inline]
[<ffffff94694d6f04>] xt_socket_lookup_slow_v4+0x524/0x718 net/netfilter/xt_socket.c:178

Fix this by copying data into appropriate size headers based on protocol.

Fixes: a583636a83 ("inet: refactor inet[6]_lookup functions to take skb")
Signed-off-by: Tejaswi Tanikella <tejaswit@codeaurora.org>
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-03-24 21:17:14 +01:00
Eric Dumazet 1bfa26ff8c ipv6: fix possible deadlock in rt6_age_examine_exception()
syzbot reported a LOCKDEP splat [1] in rt6_age_examine_exception()

rt6_age_examine_exception() is called while rt6_exception_lock is held.
This lock is the lower one in the lock hierarchy, thus we can not
call dst_neigh_lookup() function, as it can fallback to neigh_create()

We should instead do a pure RCU lookup. As a bonus we avoid
a pair of atomic operations on neigh refcount.

[1]

WARNING: possible circular locking dependency detected
4.16.0-rc4+ #277 Not tainted

syz-executor7/4015 is trying to acquire lock:
 (&ndev->lock){++--}, at: [<00000000416dce19>] __ipv6_dev_mc_dec+0x45/0x350 net/ipv6/mcast.c:928

but task is already holding lock:
 (&tbl->lock){++-.}, at: [<00000000b5cb1d65>] neigh_ifdown+0x3d/0x250 net/core/neighbour.c:292

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (&tbl->lock){++-.}:
       __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
       _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:312
       __neigh_create+0x87e/0x1d90 net/core/neighbour.c:528
       neigh_create include/net/neighbour.h:315 [inline]
       ip6_neigh_lookup+0x9a7/0xba0 net/ipv6/route.c:228
       dst_neigh_lookup include/net/dst.h:405 [inline]
       rt6_age_examine_exception net/ipv6/route.c:1609 [inline]
       rt6_age_exceptions+0x381/0x660 net/ipv6/route.c:1645
       fib6_age+0xfb/0x140 net/ipv6/ip6_fib.c:2033
       fib6_clean_node+0x389/0x580 net/ipv6/ip6_fib.c:1919
       fib6_walk_continue+0x46c/0x8a0 net/ipv6/ip6_fib.c:1845
       fib6_walk+0x91/0xf0 net/ipv6/ip6_fib.c:1893
       fib6_clean_tree+0x1e6/0x340 net/ipv6/ip6_fib.c:1970
       __fib6_clean_all+0x1f4/0x3a0 net/ipv6/ip6_fib.c:1986
       fib6_clean_all net/ipv6/ip6_fib.c:1997 [inline]
       fib6_run_gc+0x16b/0x3c0 net/ipv6/ip6_fib.c:2053
       ndisc_netdev_event+0x3c2/0x4a0 net/ipv6/ndisc.c:1781
       notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
       __raw_notifier_call_chain kernel/notifier.c:394 [inline]
       raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
       call_netdevice_notifiers_info+0x32/0x70 net/core/dev.c:1707
       call_netdevice_notifiers net/core/dev.c:1725 [inline]
       __dev_notify_flags+0x262/0x430 net/core/dev.c:6960
       dev_change_flags+0xf5/0x140 net/core/dev.c:6994
       devinet_ioctl+0x126a/0x1ac0 net/ipv4/devinet.c:1080
       inet_ioctl+0x184/0x310 net/ipv4/af_inet.c:919
       sock_do_ioctl+0xef/0x390 net/socket.c:957
       sock_ioctl+0x36b/0x610 net/socket.c:1081
       vfs_ioctl fs/ioctl.c:46 [inline]
       do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
       SYSC_ioctl fs/ioctl.c:701 [inline]
       SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
       do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

-> #2 (rt6_exception_lock){+.-.}:
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
       _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168
       spin_lock_bh include/linux/spinlock.h:315 [inline]
       rt6_flush_exceptions+0x21/0x210 net/ipv6/route.c:1367
       fib6_del_route net/ipv6/ip6_fib.c:1677 [inline]
       fib6_del+0x624/0x12c0 net/ipv6/ip6_fib.c:1761
       __ip6_del_rt+0xc7/0x120 net/ipv6/route.c:2980
       ip6_del_rt+0x132/0x1a0 net/ipv6/route.c:2993
       __ipv6_dev_ac_dec+0x3b1/0x600 net/ipv6/anycast.c:332
       ipv6_dev_ac_dec net/ipv6/anycast.c:345 [inline]
       ipv6_sock_ac_close+0x2b4/0x3e0 net/ipv6/anycast.c:200
       inet6_release+0x48/0x70 net/ipv6/af_inet6.c:433
       sock_release+0x8d/0x1e0 net/socket.c:594
       sock_close+0x16/0x20 net/socket.c:1149
       __fput+0x327/0x7e0 fs/file_table.c:209
       ____fput+0x15/0x20 fs/file_table.c:243
       task_work_run+0x199/0x270 kernel/task_work.c:113
       exit_task_work include/linux/task_work.h:22 [inline]
       do_exit+0x9bb/0x1ad0 kernel/exit.c:865
       do_group_exit+0x149/0x400 kernel/exit.c:968
       get_signal+0x73a/0x16d0 kernel/signal.c:2469
       do_signal+0x90/0x1e90 arch/x86/kernel/signal.c:809
       exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:162
       prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
       syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
       do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

-> #1 (&(&tb->tb6_lock)->rlock){+.-.}:
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
       _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168
       spin_lock_bh include/linux/spinlock.h:315 [inline]
       __ip6_ins_rt+0x56/0x90 net/ipv6/route.c:1007
       ip6_route_add+0x141/0x190 net/ipv6/route.c:2955
       addrconf_prefix_route+0x44f/0x620 net/ipv6/addrconf.c:2359
       fixup_permanent_addr net/ipv6/addrconf.c:3368 [inline]
       addrconf_permanent_addr net/ipv6/addrconf.c:3391 [inline]
       addrconf_notify+0x1ad2/0x2310 net/ipv6/addrconf.c:3460
       notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
       __raw_notifier_call_chain kernel/notifier.c:394 [inline]
       raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
       call_netdevice_notifiers_info+0x32/0x70 net/core/dev.c:1707
       call_netdevice_notifiers net/core/dev.c:1725 [inline]
       __dev_notify_flags+0x15d/0x430 net/core/dev.c:6958
       dev_change_flags+0xf5/0x140 net/core/dev.c:6994
       do_setlink+0xa22/0x3bb0 net/core/rtnetlink.c:2357
       rtnl_newlink+0xf37/0x1a50 net/core/rtnetlink.c:2965
       rtnetlink_rcv_msg+0x57f/0xb10 net/core/rtnetlink.c:4641
       netlink_rcv_skb+0x14b/0x380 net/netlink/af_netlink.c:2444
       rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4659
       netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline]
       netlink_unicast+0x4c4/0x6b0 net/netlink/af_netlink.c:1334
       netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1897
       sock_sendmsg_nosec net/socket.c:629 [inline]
       sock_sendmsg+0xca/0x110 net/socket.c:639
       ___sys_sendmsg+0x767/0x8b0 net/socket.c:2047
       __sys_sendmsg+0xe5/0x210 net/socket.c:2081
       SYSC_sendmsg net/socket.c:2092 [inline]
       SyS_sendmsg+0x2d/0x50 net/socket.c:2088
       do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

-> #0 (&ndev->lock){++--}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
       __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
       _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:312
       __ipv6_dev_mc_dec+0x45/0x350 net/ipv6/mcast.c:928
       ipv6_dev_mc_dec+0x110/0x1f0 net/ipv6/mcast.c:961
       pndisc_destructor+0x21a/0x340 net/ipv6/ndisc.c:392
       pneigh_ifdown net/core/neighbour.c:695 [inline]
       neigh_ifdown+0x149/0x250 net/core/neighbour.c:294
       rt6_disable_ip+0x537/0x700 net/ipv6/route.c:3874
       addrconf_ifdown+0x14b/0x14f0 net/ipv6/addrconf.c:3633
       addrconf_notify+0x5f8/0x2310 net/ipv6/addrconf.c:3557
       notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
       __raw_notifier_call_chain kernel/notifier.c:394 [inline]
       raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
       call_netdevice_notifiers_info+0x32/0x70 net/core/dev.c:1707
       call_netdevice_notifiers net/core/dev.c:1725 [inline]
       __dev_notify_flags+0x262/0x430 net/core/dev.c:6960
       dev_change_flags+0xf5/0x140 net/core/dev.c:6994
       devinet_ioctl+0x126a/0x1ac0 net/ipv4/devinet.c:1080
       inet_ioctl+0x184/0x310 net/ipv4/af_inet.c:919
       packet_ioctl+0x1ff/0x310 net/packet/af_packet.c:4066
       sock_do_ioctl+0xef/0x390 net/socket.c:957
       sock_ioctl+0x36b/0x610 net/socket.c:1081
       vfs_ioctl fs/ioctl.c:46 [inline]
       do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
       SYSC_ioctl fs/ioctl.c:701 [inline]
       SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
       do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

other info that might help us debug this:

Chain exists of:
  &ndev->lock --> rt6_exception_lock --> &tbl->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&tbl->lock);
                               lock(rt6_exception_lock);
                               lock(&tbl->lock);
  lock(&ndev->lock);

 *** DEADLOCK ***

2 locks held by syz-executor7/4015:
 #0:  (rtnl_mutex){+.+.}, at: [<00000000a2f16daa>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
 #1:  (&tbl->lock){++-.}, at: [<00000000b5cb1d65>] neigh_ifdown+0x3d/0x250 net/core/neighbour.c:292

stack backtrace:
CPU: 0 PID: 4015 Comm: syz-executor7 Not tainted 4.16.0-rc4+ #277
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x24d lib/dump_stack.c:53
 print_circular_bug.isra.38+0x2cd/0x2dc kernel/locking/lockdep.c:1223
 check_prev_add kernel/locking/lockdep.c:1863 [inline]
 check_prevs_add kernel/locking/lockdep.c:1976 [inline]
 validate_chain kernel/locking/lockdep.c:2417 [inline]
 __lock_acquire+0x30a8/0x3e00 kernel/locking/lockdep.c:3431
 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
 __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
 _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:312
 __ipv6_dev_mc_dec+0x45/0x350 net/ipv6/mcast.c:928
 ipv6_dev_mc_dec+0x110/0x1f0 net/ipv6/mcast.c:961
 pndisc_destructor+0x21a/0x340 net/ipv6/ndisc.c:392
 pneigh_ifdown net/core/neighbour.c:695 [inline]
 neigh_ifdown+0x149/0x250 net/core/neighbour.c:294
 rt6_disable_ip+0x537/0x700 net/ipv6/route.c:3874
 addrconf_ifdown+0x14b/0x14f0 net/ipv6/addrconf.c:3633
 addrconf_notify+0x5f8/0x2310 net/ipv6/addrconf.c:3557
 notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
 __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
 call_netdevice_notifiers_info+0x32/0x70 net/core/dev.c:1707
 call_netdevice_notifiers net/core/dev.c:1725 [inline]
 __dev_notify_flags+0x262/0x430 net/core/dev.c:6960
 dev_change_flags+0xf5/0x140 net/core/dev.c:6994
 devinet_ioctl+0x126a/0x1ac0 net/ipv4/devinet.c:1080
 inet_ioctl+0x184/0x310 net/ipv4/af_inet.c:919
 packet_ioctl+0x1ff/0x310 net/packet/af_packet.c:4066
 sock_do_ioctl+0xef/0x390 net/socket.c:957
 sock_ioctl+0x36b/0x610 net/socket.c:1081
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Fixes: c757faa8bf ("ipv6: prepare fib6_age() for exception table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Acked-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23 13:40:34 -04:00