Commit Graph

45009 Commits

Author SHA1 Message Date
36ee106e84 tcp: add tcp_ooo_try_coalesce() helper
commit 58152ecbbc upstream.

In case skb in out_or_order_queue is the result of
multiple skbs coalescing, we would like to get a proper gso_segs
counter tracking, so that future tcp_drop() can report an accurate
number.

I chose to not implement this tracking for skbs in receive queue,
since they are not dropped, unless socket is disconnected.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-09 12:18:00 +02:00
c68c772262 netlink: Don't shift on 64 for ngroups
commit 91874ecf32 upstream.

It's legal to have 64 groups for netlink_sock.

As user-supplied nladdr->nl_groups is __u32, it's possible to subscribe
only to first 32 groups.

The check for correctness of .bind() userspace supplied parameter
is done by applying mask made from ngroups shift. Which broke Android
as they have 64 groups and the shift for mask resulted in an overflow.

Fixes: 61f4b23769 ("netlink: Don't shift with UB on nlk->ngroups")
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: netdev@vger.kernel.org
Cc: stable@vger.kernel.org
Reported-and-Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-09 12:17:59 +02:00
4d502572ea netlink: Don't shift with UB on nlk->ngroups
[ Upstream commit 61f4b23769 ]

On i386 nlk->ngroups might be 32 or 0. Which leads to UB, resulting in
hang during boot.
Check for 0 ngroups and use (unsigned long long) as a type to shift.

Fixes: 7acf9d4237 ("netlink: Do not subscribe to non-existent groups").
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-09 12:17:59 +02:00
4f08437d6c netlink: Do not subscribe to non-existent groups
[ Upstream commit 7acf9d4237 ]

Make ABI more strict about subscribing to group > ngroups.
Code doesn't check for that and it looks bogus.
(one can subscribe to non-existing group)
Still, it's possible to bind() to all possible groups with (-1)

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: netdev@vger.kernel.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-09 12:17:58 +02:00
9a492f8c71 net: socket: fix potential spectre v1 gadget in socketcall
commit c8e8cd579b upstream.

'call' is a user-controlled value, so sanitize the array index after the
bounds check to avoid speculating past the bounds of the 'nargs' array.

Found with the help of Smatch:

net/socket.c:2508 __do_sys_socketcall() warn: potential spectre issue
'nargs' [r] (local cap)

Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jeremy Cline <jcline@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06 16:23:04 +02:00
67f0a2887b netlink: Fix spectre v1 gadget in netlink_create()
[ Upstream commit bc5b6c0b62 ]

'protocol' is a user-controlled value, so sanitize it after the bounds
check to avoid using it for speculative out-of-bounds access to arrays
indexed by it.

This addresses the following accesses detected with the help of smatch:

* net/netlink/af_netlink.c:654 __netlink_create() warn: potential
  spectre issue 'nlk_cb_mutex_keys' [w]

* net/netlink/af_netlink.c:654 __netlink_create() warn: potential
  spectre issue 'nlk_cb_mutex_key_strings' [w]

* net/netlink/af_netlink.c:685 netlink_create() warn: potential spectre
  issue 'nl_table' [w] (local cap)

Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jeremy Cline <jcline@redhat.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06 16:23:03 +02:00
ab9a0f80bc net: dsa: Do not suspend/resume closed slave_dev
[ Upstream commit a94c689e6c ]

If a DSA slave network device was previously disabled, there is no need
to suspend or resume it.

Fixes: 2446254915 ("net: dsa: allow switch drivers to implement suspend/resume hooks")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06 16:23:03 +02:00
d59dcdf13e ipv4: frags: handle possible skb truesize change
[ Upstream commit 4672694bd4 ]

ip_frag_queue() might call pskb_pull() on one skb that
is already in the fragment queue.

We need to take care of possible truesize change, or we
might have an imbalance of the netns frags memory usage.

IPv6 is immune to this bug, because RFC5722, Section 4,
amended by Errata ID 3089 states :

  When reassembling an IPv6 datagram, if
  one or more its constituent fragments is determined to be an
  overlapping fragment, the entire datagram (and any constituent
  fragments) MUST be silently discarded.

Fixes: 158f323b98 ("net: adjust skb->truesize in pskb_expand_head()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06 16:23:03 +02:00
c5282a032f inet: frag: enforce memory limits earlier
[ Upstream commit 56e2c94f05 ]

We currently check current frags memory usage only when
a new frag queue is created. This allows attackers to first
consume the memory budget (default : 4 MB) creating thousands
of frag queues, then sending tiny skbs to exceed high_thresh
limit by 2 to 3 order of magnitude.

Note that before commit 648700f76b ("inet: frags: use rhashtables
for reassembly units"), work queue could be starved under DOS,
getting no cpu cycles.
After commit 648700f76b, only the per frag queue timer can eventually
remove an incomplete frag queue and its skbs.

Fixes: b13d3cbfb8 ("inet: frag: move eviction of queues to work queue")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Peter Oskolkov <posk@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06 16:23:03 +02:00
019ea5193f tcp: add one more quick ack after after ECN events
[ Upstream commit 15ecbe94a4 ]

Larry Brakmo proposal ( https://patchwork.ozlabs.org/patch/935233/
tcp: force cwnd at least 2 in tcp_cwnd_reduction) made us rethink
about our recent patch removing ~16 quick acks after ECN events.

tcp_enter_quickack_mode(sk, 1) makes sure one immediate ack is sent,
but in the case the sender cwnd was lowered to 1, we do not want
to have a delayed ack for the next packet we will receive.

Fixes: 522040ea5f ("tcp: do not aggressively quick ack after ECN events")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Neal Cardwell <ncardwell@google.com>
Cc: Lawrence Brakmo <brakmo@fb.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06 16:23:02 +02:00
095ab5f46c tcp: refactor tcp_ecn_check_ce to remove sk type cast
[ Upstream commit f4c9f85f3b ]

Refactor tcp_ecn_check_ce and __tcp_ecn_check_ce to accept struct sock*
instead of tcp_sock* to clean up type casts. This is a pure refactor
patch.

Signed-off-by: Yousuk Seung <ysseung@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06 16:23:02 +02:00
65d986cb5e tcp: do not aggressively quick ack after ECN events
[ Upstream commit 522040ea5f ]

ECN signals currently forces TCP to enter quickack mode for
up to 16 (TCP_MAX_QUICKACKS) following incoming packets.

We believe this is not needed, and only sending one immediate ack
for the current packet should be enough.

This should reduce the extra load noticed in DCTCP environments,
after congestion events.

This is part 2 of our effort to reduce pure ACK packets.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06 16:23:02 +02:00
90cf17d665 tcp: add max_quickacks param to tcp_incr_quickack and tcp_enter_quickack_mode
[ Upstream commit 9a9c9b51e5 ]

We want to add finer control of the number of ACK packets sent after
ECN events.

This patch is not changing current behavior, it only enables following
change.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06 16:23:02 +02:00
8ca41e4efc tcp: do not force quickack when receiving out-of-order packets
[ Upstream commit a3893637e1 ]

As explained in commit 9f9843a751 ("tcp: properly handle stretch
acks in slow start"), TCP stacks have to consider how many packets
are acknowledged in one single ACK, because of GRO, but also
because of ACK compression or losses.

We plan to add SACK compression in the following patch, we
must therefore not call tcp_enter_quickack_mode()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06 16:23:02 +02:00
b3e349fd55 tcp_bbr: fix bw probing to raise in-flight data for very small BDPs
[ Upstream commit 383d470936 ]

For some very small BDPs (with just a few packets) there was a
quantization effect where the target number of packets in flight
during the super-unity-gain (1.25x) phase of gain cycling was
implicitly truncated to a number of packets no larger than the normal
unity-gain (1.0x) phase of gain cycling. This meant that in multi-flow
scenarios some flows could get stuck with a lower bandwidth, because
they did not push enough packets inflight to discover that there was
more bandwidth available. This was really only an issue in multi-flow
LAN scenarios, where RTTs and BDPs are low enough for this to be an
issue.

This fix ensures that gain cycling can raise inflight for small BDPs
by ensuring that in PROBE_BW mode target inflight values with a
super-unity gain are always greater than inflight values with a gain
<= 1. Importantly, this applies whether the inflight value is
calculated for use as a cwnd value, or as a target inflight value for
the end of the super-unity phase in bbr_is_next_cycle_phase() (both
need to be bigger to ensure we can probe with more packets in flight
reliably).

This is a candidate fix for stable releases.

Fixes: 0f8782ea14 ("tcp_bbr: add BBR congestion control")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Priyaranjan Jha <priyarjha@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06 16:23:01 +02:00
e364f1a2cc ipv4: remove BUG_ON() from fib_compute_spec_dst
[ Upstream commit 9fc12023d6 ]

Remove BUG_ON() from fib_compute_spec_dst routine and check
in_dev pointer during flowi4 data structure initialization.
fib_compute_spec_dst routine can be run concurrently with device removal
where ip_ptr net_device pointer is set to NULL. This can happen
if userspace enables pkt info on UDP rx socket and the device
is removed while traffic is flowing

Fixes: 35ebf65e85 ("ipv4: Create and use fib_compute_spec_dst() helper")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06 16:23:01 +02:00
34447a69c9 ipconfig: Correctly initialise ic_nameservers
[ Upstream commit 300eec7c0a ]

ic_nameservers, which stores the list of name servers discovered by
ipconfig, is initialised (i.e. has all of its elements set to NONE, or
0xffffffff) by ic_nameservers_predef() in the following scenarios:

 - before the "ip=" and "nfsaddrs=" kernel command line parameters are
   parsed (in ip_auto_config_setup());
 - before autoconfiguring via DHCP or BOOTP (in ic_bootp_init()), in
   order to clear any values that may have been set after parsing "ip="
   or "nfsaddrs=" and are no longer needed.

This means that ic_nameservers_predef() is not called when neither "ip="
nor "nfsaddrs=" is specified on the kernel command line. In this
scenario, every element in ic_nameservers remains set to 0x00000000,
which is indistinguishable from ANY and causes pnp_seq_show() to write
the following (bogus) information to /proc/net/pnp:

  #MANUAL
  nameserver 0.0.0.0
  nameserver 0.0.0.0
  nameserver 0.0.0.0

This is potentially problematic for systems that blindly link
/etc/resolv.conf to /proc/net/pnp.

Ensure that ic_nameservers is also initialised when neither "ip=" nor
"nfsaddrs=" are specified by calling ic_nameservers_predef() in
ip_auto_config(), but only when ip_auto_config_setup() was not called
earlier. This causes the following to be written to /proc/net/pnp, and
is consistent with what gets written when ipconfig is configured
manually but no name servers are specified on the kernel command line:

  #MANUAL

Signed-off-by: Chris Novakovic <chris@chrisn.me.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-03 07:55:24 +02:00
759fb7f94f netfilter: nf_tables: check msg_type before nft_trans_set(trans)
[ Upstream commit 9c7f96fd77 ]

The patch moves the "trans->msg_type == NFT_MSG_NEWSET" check before
using nft_trans_set(trans). Otherwise we can get out of bounds read.

For example, KASAN reported the one when running 0001_cache_handling_0 nft
test. In this case "trans->msg_type" was NFT_MSG_NEWTABLE:

[75517.177808] BUG: KASAN: slab-out-of-bounds in nft_set_lookup_global+0x22f/0x270 [nf_tables]
[75517.279094] Read of size 8 at addr ffff881bdb643fc8 by task nft/7356
...
[75517.375605] CPU: 26 PID: 7356 Comm: nft Tainted: G  E   4.17.0-rc7.1.x86_64 #1
[75517.489587] Hardware name: Oracle Corporation SUN SERVER X4-2
[75517.618129] Call Trace:
[75517.648821]  dump_stack+0xd1/0x13b
[75517.691040]  ? show_regs_print_info+0x5/0x5
[75517.742519]  ? kmsg_dump_rewind_nolock+0xf5/0xf5
[75517.799300]  ? lock_acquire+0x143/0x310
[75517.846738]  print_address_description+0x85/0x3a0
[75517.904547]  kasan_report+0x18d/0x4b0
[75517.949892]  ? nft_set_lookup_global+0x22f/0x270 [nf_tables]
[75518.019153]  ? nft_set_lookup_global+0x22f/0x270 [nf_tables]
[75518.088420]  ? nft_set_lookup_global+0x22f/0x270 [nf_tables]
[75518.157689]  nft_set_lookup_global+0x22f/0x270 [nf_tables]
[75518.224869]  nf_tables_newsetelem+0x1a5/0x5d0 [nf_tables]
[75518.291024]  ? nft_add_set_elem+0x2280/0x2280 [nf_tables]
[75518.357154]  ? nla_parse+0x1a5/0x300
[75518.401455]  ? kasan_kmalloc+0xa6/0xd0
[75518.447842]  nfnetlink_rcv+0xc43/0x1bdf [nfnetlink]
[75518.507743]  ? nfnetlink_rcv+0x7a5/0x1bdf [nfnetlink]
[75518.569745]  ? nfnl_err_reset+0x3c0/0x3c0 [nfnetlink]
[75518.631711]  ? lock_acquire+0x143/0x310
[75518.679133]  ? netlink_deliver_tap+0x9b/0x1070
[75518.733840]  ? kasan_unpoison_shadow+0x31/0x40
[75518.788542]  netlink_unicast+0x45d/0x680
[75518.837111]  ? __isolate_free_page+0x890/0x890
[75518.891913]  ? netlink_attachskb+0x6b0/0x6b0
[75518.944542]  netlink_sendmsg+0x6fa/0xd30
[75518.993107]  ? netlink_unicast+0x680/0x680
[75519.043758]  ? netlink_unicast+0x680/0x680
[75519.094402]  sock_sendmsg+0xd9/0x160
[75519.138810]  ___sys_sendmsg+0x64d/0x980
[75519.186234]  ? copy_msghdr_from_user+0x350/0x350
[75519.243118]  ? lock_downgrade+0x650/0x650
[75519.292738]  ? do_raw_spin_unlock+0x5d/0x250
[75519.345456]  ? _raw_spin_unlock+0x24/0x30
[75519.395065]  ? __handle_mm_fault+0xbde/0x3410
[75519.448830]  ? sock_setsockopt+0x3d2/0x1940
[75519.500516]  ? __lock_acquire.isra.25+0xdc/0x19d0
[75519.558448]  ? lock_downgrade+0x650/0x650
[75519.608057]  ? __audit_syscall_entry+0x317/0x720
[75519.664960]  ? __fget_light+0x58/0x250
[75519.711325]  ? __sys_sendmsg+0xde/0x170
[75519.758850]  __sys_sendmsg+0xde/0x170
[75519.804193]  ? __ia32_sys_shutdown+0x90/0x90
[75519.856725]  ? syscall_trace_enter+0x897/0x10e0
[75519.912354]  ? trace_event_raw_event_sys_enter+0x920/0x920
[75519.979432]  ? __audit_syscall_entry+0x720/0x720
[75520.036118]  do_syscall_64+0xa3/0x3d0
[75520.081248]  ? prepare_exit_to_usermode+0x47/0x1d0
[75520.139904]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[75520.201680] RIP: 0033:0x7fc153320ba0
[75520.245772] RSP: 002b:00007ffe294c3638 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[75520.337708] RAX: ffffffffffffffda RBX: 00007ffe294c4820 RCX: 00007fc153320ba0
[75520.424547] RDX: 0000000000000000 RSI: 00007ffe294c46b0 RDI: 0000000000000003
[75520.511386] RBP: 00007ffe294c47b0 R08: 0000000000000004 R09: 0000000002114090
[75520.598225] R10: 00007ffe294c30a0 R11: 0000000000000246 R12: 00007ffe294c3660
[75520.684961] R13: 0000000000000001 R14: 00007ffe294c3650 R15: 0000000000000001

[75520.790946] Allocated by task 7356:
[75520.833994]  kasan_kmalloc+0xa6/0xd0
[75520.878088]  __kmalloc+0x189/0x450
[75520.920107]  nft_trans_alloc_gfp+0x20/0x190 [nf_tables]
[75520.983961]  nf_tables_newtable+0xcd0/0x1bd0 [nf_tables]
[75521.048857]  nfnetlink_rcv+0xc43/0x1bdf [nfnetlink]
[75521.108655]  netlink_unicast+0x45d/0x680
[75521.157013]  netlink_sendmsg+0x6fa/0xd30
[75521.205271]  sock_sendmsg+0xd9/0x160
[75521.249365]  ___sys_sendmsg+0x64d/0x980
[75521.296686]  __sys_sendmsg+0xde/0x170
[75521.341822]  do_syscall_64+0xa3/0x3d0
[75521.386957]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[75521.467867] Freed by task 23454:
[75521.507804]  __kasan_slab_free+0x132/0x180
[75521.558137]  kfree+0x14d/0x4d0
[75521.596005]  free_rt_sched_group+0x153/0x280
[75521.648410]  sched_autogroup_create_attach+0x19a/0x520
[75521.711330]  ksys_setsid+0x2ba/0x400
[75521.755529]  __ia32_sys_setsid+0xa/0x10
[75521.802850]  do_syscall_64+0xa3/0x3d0
[75521.848090]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[75521.929000] The buggy address belongs to the object at ffff881bdb643f80
 which belongs to the cache kmalloc-96 of size 96
[75522.079797] The buggy address is located 72 bytes inside of
 96-byte region [ffff881bdb643f80, ffff881bdb643fe0)
[75522.221234] The buggy address belongs to the page:
[75522.280100] page:ffffea006f6d90c0 count:1 mapcount:0 mapping:0000000000000000 index:0x0
[75522.377443] flags: 0x2fffff80000100(slab)
[75522.426956] raw: 002fffff80000100 0000000000000000 0000000000000000 0000000180200020
[75522.521275] raw: ffffea006e6fafc0 0000000c0000000c ffff881bf180f400 0000000000000000
[75522.615601] page dumped because: kasan: bad access detected

Fixes: 37a9cc5255 ("netfilter: nf_tables: add generation mask to sets")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-03 07:55:14 +02:00
94623c7463 tcp: call tcp_drop() from tcp_data_queue_ofo()
[ Upstream commit 8541b21e78 ]

In order to be able to give better diagnostics and detect
malicious traffic, we need to have better sk->sk_drops tracking.

Fixes: 9f5afeae51 ("tcp: use an RB tree for ooo receive queue")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28 07:49:12 +02:00
a878681484 tcp: detect malicious patterns in tcp_collapse_ofo_queue()
[ Upstream commit 3d4bf93ac1 ]

In case an attacker feeds tiny packets completely out of order,
tcp_collapse_ofo_queue() might scan the whole rb-tree, performing
expensive copies, but not changing socket memory usage at all.

1) Do not attempt to collapse tiny skbs.
2) Add logic to exit early when too many tiny skbs are detected.

We prefer not doing aggressive collapsing (which copies packets)
for pathological flows, and revert to tcp_prune_ofo_queue() which
will be less expensive.

In the future, we might add the possibility of terminating flows
that are proven to be malicious.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28 07:49:12 +02:00
fdf258ed5d tcp: avoid collapses in tcp_prune_queue() if possible
[ Upstream commit f4a3313d8e ]

Right after a TCP flow is created, receiving tiny out of order
packets allways hit the condition :

if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
	tcp_clamp_window(sk);

tcp_clamp_window() increases sk_rcvbuf to match sk_rmem_alloc
(guarded by tcp_rmem[2])

Calling tcp_collapse_ofo_queue() in this case is not useful,
and offers a O(N^2) surface attack to malicious peers.

Better not attempt anything before full queue capacity is reached,
forcing attacker to spend lots of resource and allow us to more
easily detect the abuse.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28 07:49:12 +02:00
2d08921c8d tcp: free batches of packets in tcp_prune_ofo_queue()
[ Upstream commit 72cd43ba64 ]

Juha-Matti Tilli reported that malicious peers could inject tiny
packets in out_of_order_queue, forcing very expensive calls
to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() for
every incoming packet. out_of_order_queue rb-tree can contain
thousands of nodes, iterating over all of them is not nice.

Before linux-4.9, we would have pruned all packets in ofo_queue
in one go, every XXXX packets. XXXX depends on sk_rcvbuf and skbs
truesize, but is about 7000 packets with tcp_rmem[2] default of 6 MB.

Since we plan to increase tcp_rmem[2] in the future to cope with
modern BDP, can not revert to the old behavior, without great pain.

Strategy taken in this patch is to purge ~12.5 % of the queue capacity.

Fixes: 36a6503fed ("tcp: refine tcp_prune_ofo_queue() to not drop all packets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Juha-Matti Tilli <juha-matti.tilli@iki.fi>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28 07:49:12 +02:00
8736711f4e tcp: do not delay ACK in DCTCP upon CE status change
[ Upstream commit a0496ef2c2 ]

Per DCTCP RFC8257 (Section 3.2) the ACK reflecting the CE status change
has to be sent immediately so the sender can respond quickly:

""" When receiving packets, the CE codepoint MUST be processed as follows:

   1.  If the CE codepoint is set and DCTCP.CE is false, set DCTCP.CE to
       true and send an immediate ACK.

   2.  If the CE codepoint is not set and DCTCP.CE is true, set DCTCP.CE
       to false and send an immediate ACK.
"""

Previously DCTCP implementation may continue to delay the ACK. This
patch fixes that to implement the RFC by forcing an immediate ACK.

Tested with this packetdrill script provided by Larry Brakmo

0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
0.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
0.000 setsockopt(3, SOL_TCP, TCP_CONGESTION, "dctcp", 5) = 0
0.000 bind(3, ..., ...) = 0
0.000 listen(3, 1) = 0

0.100 < [ect0] SEW 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>
0.100 > SE. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
0.110 < [ect0] . 1:1(0) ack 1 win 257
0.200 accept(3, ..., ...) = 4
   +0 setsockopt(4, SOL_SOCKET, SO_DEBUG, [1], 4) = 0

0.200 < [ect0] . 1:1001(1000) ack 1 win 257
0.200 > [ect01] . 1:1(0) ack 1001

0.200 write(4, ..., 1) = 1
0.200 > [ect01] P. 1:2(1) ack 1001

0.200 < [ect0] . 1001:2001(1000) ack 2 win 257
+0.005 < [ce] . 2001:3001(1000) ack 2 win 257

+0.000 > [ect01] . 2:2(0) ack 2001
// Previously the ACK below would be delayed by 40ms
+0.000 > [ect01] E. 2:2(0) ack 3001

+0.500 < F. 9501:9501(0) ack 4 win 257

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28 07:49:12 +02:00
57ec8824b1 tcp: do not cancel delay-AcK on DCTCP special ACK
[ Upstream commit 27cde44a25 ]

Currently when a DCTCP receiver delays an ACK and receive a
data packet with a different CE mark from the previous one's, it
sends two immediate ACKs acking previous and latest sequences
respectly (for ECN accounting).

Previously sending the first ACK may mark off the delayed ACK timer
(tcp_event_ack_sent). This may subsequently prevent sending the
second ACK to acknowledge the latest sequence (tcp_ack_snd_check).
The culprit is that tcp_send_ack() assumes it always acknowleges
the latest sequence, which is not true for the first special ACK.

The fix is to not make the assumption in tcp_send_ack and check the
actual ack sequence before cancelling the delayed ACK. Further it's
safer to pass the ack sequence number as a local variable into
tcp_send_ack routine, instead of intercepting tp->rcv_nxt to avoid
future bugs like this.

Reported-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28 07:49:12 +02:00
1fcccc5786 tcp: helpers to send special DCTCP ack
[ Upstream commit 2987babb69 ]

Refactor and create helpers to send the special ACK in DCTCP.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28 07:49:12 +02:00
8417780182 tcp: fix dctcp delayed ACK schedule
[ Upstream commit b0c05d0e99 ]

Previously, when a data segment was sent an ACK was piggybacked
on the data segment without generating a CA_EVENT_NON_DELAYED_ACK
event to notify congestion control modules. So the DCTCP
ca->delayed_ack_reserved flag could incorrectly stay set when
in fact there were no delayed ACKs being reserved. This could result
in sending a special ECN notification ACK that carries an older
ACK sequence, when in fact there was no need for such an ACK.
DCTCP keeps track of the delayed ACK status with its own separate
state ca->delayed_ack_reserved. Previously it may accidentally cancel
the delayed ACK without updating this field upon sending a special
ACK that carries a older ACK sequence. This inconsistency would
lead to DCTCP receiver never acknowledging the latest data until the
sender times out and retry in some cases.

Packetdrill script (provided by Larry Brakmo)

0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
0.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
0.000 setsockopt(3, SOL_TCP, TCP_CONGESTION, "dctcp", 5) = 0
0.000 bind(3, ..., ...) = 0
0.000 listen(3, 1) = 0

0.100 < [ect0] SEW 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>
0.100 > SE. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
0.110 < [ect0] . 1:1(0) ack 1 win 257
0.200 accept(3, ..., ...) = 4

0.200 < [ect0] . 1:1001(1000) ack 1 win 257
0.200 > [ect01] . 1:1(0) ack 1001

0.200 write(4, ..., 1) = 1
0.200 > [ect01] P. 1:2(1) ack 1001

0.200 < [ect0] . 1001:2001(1000) ack 2 win 257
0.200 write(4, ..., 1) = 1
0.200 > [ect01] P. 2:3(1) ack 2001

0.200 < [ect0] . 2001:3001(1000) ack 3 win 257
0.200 < [ect0] . 3001:4001(1000) ack 3 win 257
0.200 > [ect01] . 3:3(0) ack 4001

0.210 < [ce] P. 4001:4501(500) ack 3 win 257

+0.001 read(4, ..., 4500) = 4500
+0 write(4, ..., 1) = 1
+0 > [ect01] PE. 3:4(1) ack 4501

+0.010 < [ect0] W. 4501:5501(1000) ack 4 win 257
// Previously the ACK sequence below would be 4501, causing a long RTO
+0.040~+0.045 > [ect01] . 4:4(0) ack 5501   // delayed ack

+0.311 < [ect0] . 5501:6501(1000) ack 4 win 257  // More data
+0 > [ect01] . 4:4(0) ack 6501     // now acks everything

+0.500 < F. 9501:9501(0) ack 4 win 257

Reported-by: Larry Brakmo <brakmo@fb.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Lawrence Brakmo <brakmo@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28 07:49:12 +02:00
19b7479915 rtnetlink: add rtnl_link_state check in rtnl_configure_link
[ Upstream commit 5025f7f7d5 ]

rtnl_configure_link sets dev->rtnl_link_state to
RTNL_LINK_INITIALIZED and unconditionally calls
__dev_notify_flags to notify user-space of dev flags.

current call sequence for rtnl_configure_link
rtnetlink_newlink
    rtnl_link_ops->newlink
    rtnl_configure_link (unconditionally notifies userspace of
                         default and new dev flags)

If a newlink handler wants to call rtnl_configure_link
early, we will end up with duplicate notifications to
user-space.

This patch fixes rtnl_configure_link to check rtnl_link_state
and call __dev_notify_flags with gchanges = 0 if already
RTNL_LINK_INITIALIZED.

Later in the series, this patch will help the following sequence
where a driver implementing newlink can call rtnl_configure_link
to initialize the link early.

makes the following call sequence work:
rtnetlink_newlink
    rtnl_link_ops->newlink (vxlan) -> rtnl_configure_link (initializes
                                                link and notifies
                                                user-space of default
                                                dev flags)
    rtnl_configure_link (updates dev flags if requested by user ifm
                         and notifies user-space of new dev flags)

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28 07:49:12 +02:00
cc403d5dc1 multicast: do not restore deleted record source filter mode to new one
There are two scenarios that we will restore deleted records. The first is
when device down and up(or unmap/remap). In this scenario the new filter
mode is same with previous one. Because we get it from in_dev->mc_list and
we do not touch it during device down and up.

The other scenario is when a new socket join a group which was just delete
and not finish sending status reports. In this scenario, we should use the
current filter mode instead of restore old one. Here are 4 cases in total.

old_socket        new_socket       before_fix       after_fix
  IN(A)             IN(A)           ALLOW(A)         ALLOW(A)
  IN(A)             EX( )           TO_IN( )         TO_EX( )
  EX( )             IN(A)           TO_EX( )         ALLOW(A)
  EX( )             EX( )           TO_EX( )         TO_EX( )

Fixes: 24803f38a5 (igmp: do not remove igmp souce list info when set link down)
Fixes: 1666d49e1d (mld: do not remove mld souce list info when set link down)
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28 07:49:11 +02:00
e2ffdd646c net: skb_segment() should not return NULL
[ Upstream commit ff907a11a0 ]

syzbot caught a NULL deref [1], caused by skb_segment()

skb_segment() has many "goto err;" that assume the @err variable
contains -ENOMEM.

A successful call to __skb_linearize() should not clear @err,
otherwise a subsequent memory allocation error could return NULL.

While we are at it, we might use -EINVAL instead of -ENOMEM when
MAX_SKB_FRAGS limit is reached.

[1]
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
CPU: 0 PID: 13285 Comm: syz-executor3 Not tainted 4.18.0-rc4+ #146
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tcp_gso_segment+0x3dc/0x1780 net/ipv4/tcp_offload.c:106
Code: f0 ff ff 0f 87 1c fd ff ff e8 00 88 0b fb 48 8b 75 d0 48 b9 00 00 00 00 00 fc ff df 48 8d be 90 00 00 00 48 89 f8 48 c1 e8 03 <0f> b6 14 08 48 8d 86 94 00 00 00 48 89 c6 83 e0 07 48 c1 ee 03 0f
RSP: 0018:ffff88019b7fd060 EFLAGS: 00010206
RAX: 0000000000000012 RBX: 0000000000000020 RCX: dffffc0000000000
RDX: 0000000000040000 RSI: 0000000000000000 RDI: 0000000000000090
RBP: ffff88019b7fd0f0 R08: ffff88019510e0c0 R09: ffffed003b5c46d6
R10: ffffed003b5c46d6 R11: ffff8801dae236b3 R12: 0000000000000001
R13: ffff8801d6c581f4 R14: 0000000000000000 R15: ffff8801d6c58128
FS:  00007fcae64d6700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004e8664 CR3: 00000001b669b000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tcp4_gso_segment+0x1c3/0x440 net/ipv4/tcp_offload.c:54
 inet_gso_segment+0x64e/0x12d0 net/ipv4/af_inet.c:1342
 inet_gso_segment+0x64e/0x12d0 net/ipv4/af_inet.c:1342
 skb_mac_gso_segment+0x3b5/0x740 net/core/dev.c:2792
 __skb_gso_segment+0x3c3/0x880 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4099 [inline]
 validate_xmit_skb+0x640/0xf30 net/core/dev.c:3104
 __dev_queue_xmit+0xc14/0x3910 net/core/dev.c:3561
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3602
 neigh_hh_output include/net/neighbour.h:473 [inline]
 neigh_output include/net/neighbour.h:481 [inline]
 ip_finish_output2+0x1063/0x1860 net/ipv4/ip_output.c:229
 ip_finish_output+0x841/0xfa0 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:276 [inline]
 ip_output+0x223/0x880 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 ip_local_out+0xc5/0x1b0 net/ipv4/ip_output.c:124
 iptunnel_xmit+0x567/0x850 net/ipv4/ip_tunnel_core.c:91
 ip_tunnel_xmit+0x1598/0x3af1 net/ipv4/ip_tunnel.c:778
 ipip_tunnel_xmit+0x264/0x2c0 net/ipv4/ipip.c:308
 __netdev_start_xmit include/linux/netdevice.h:4148 [inline]
 netdev_start_xmit include/linux/netdevice.h:4157 [inline]
 xmit_one net/core/dev.c:3034 [inline]
 dev_hard_start_xmit+0x26c/0xc30 net/core/dev.c:3050
 __dev_queue_xmit+0x29ef/0x3910 net/core/dev.c:3569
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3602
 neigh_direct_output+0x15/0x20 net/core/neighbour.c:1403
 neigh_output include/net/neighbour.h:483 [inline]
 ip_finish_output2+0xa67/0x1860 net/ipv4/ip_output.c:229
 ip_finish_output+0x841/0xfa0 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:276 [inline]
 ip_output+0x223/0x880 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 ip_local_out+0xc5/0x1b0 net/ipv4/ip_output.c:124
 ip_queue_xmit+0x9df/0x1f80 net/ipv4/ip_output.c:504
 tcp_transmit_skb+0x1bf9/0x3f10 net/ipv4/tcp_output.c:1168
 tcp_write_xmit+0x1641/0x5c20 net/ipv4/tcp_output.c:2363
 __tcp_push_pending_frames+0xb2/0x290 net/ipv4/tcp_output.c:2536
 tcp_push+0x638/0x8c0 net/ipv4/tcp.c:735
 tcp_sendmsg_locked+0x2ec5/0x3f00 net/ipv4/tcp.c:1410
 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1447
 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:641 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:651
 __sys_sendto+0x3d7/0x670 net/socket.c:1797
 __do_sys_sendto net/socket.c:1809 [inline]
 __se_sys_sendto net/socket.c:1805 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1805
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455ab9
Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fcae64d5c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fcae64d66d4 RCX: 0000000000455ab9
RDX: 0000000000000001 RSI: 0000000020000200 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014
R13: 00000000004c1145 R14: 00000000004d1818 R15: 0000000000000006
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)

Fixes: ddff00d420 ("net: Move skb_has_shared_frag check out of GRE code and into segmentation")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28 07:49:11 +02:00
03fbf2b823 ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull
[ Upstream commit 2efd4fca70 ]

Syzbot reported a read beyond the end of the skb head when returning
IPV6_ORIGDSTADDR:

  BUG: KMSAN: kernel-infoleak in put_cmsg+0x5ef/0x860 net/core/scm.c:242
  CPU: 0 PID: 4501 Comm: syz-executor128 Not tainted 4.17.0+ #9
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
  Google 01/01/2011
  Call Trace:
    __dump_stack lib/dump_stack.c:77 [inline]
    dump_stack+0x185/0x1d0 lib/dump_stack.c:113
    kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1125
    kmsan_internal_check_memory+0x138/0x1f0 mm/kmsan/kmsan.c:1219
    kmsan_copy_to_user+0x7a/0x160 mm/kmsan/kmsan.c:1261
    copy_to_user include/linux/uaccess.h:184 [inline]
    put_cmsg+0x5ef/0x860 net/core/scm.c:242
    ip6_datagram_recv_specific_ctl+0x1cf3/0x1eb0 net/ipv6/datagram.c:719
    ip6_datagram_recv_ctl+0x41c/0x450 net/ipv6/datagram.c:733
    rawv6_recvmsg+0x10fb/0x1460 net/ipv6/raw.c:521
    [..]

This logic and its ipv4 counterpart read the destination port from
the packet at skb_transport_offset(skb) + 4.

With MSG_MORE and a local SOCK_RAW sender, syzbot was able to cook a
packet that stores headers exactly up to skb_transport_offset(skb) in
the head and the remainder in a frag.

Call pskb_may_pull before accessing the pointer to ensure that it lies
in skb head.

Link: http://lkml.kernel.org/r/CAF=yD-LEJwZj5a1-bAAj2Oy_hKmGygV6rsJ_WOrAYnv-fnayiQ@mail.gmail.com
Reported-by: syzbot+9adb4b567003cac781f0@syzkaller.appspotmail.com
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28 07:49:11 +02:00
93d94fec94 ip: hash fragments consistently
[ Upstream commit 3dd1c9a127 ]

The skb hash for locally generated ip[v6] fragments belonging
to the same datagram can vary in several circumstances:
* for connected UDP[v6] sockets, the first fragment get its hash
  via set_owner_w()/skb_set_hash_from_sk()
* for unconnected IPv6 UDPv6 sockets, the first fragment can get
  its hash via ip6_make_flowlabel()/skb_get_hash_flowi6(), if
  auto_flowlabel is enabled

For the following frags the hash is usually computed via
skb_get_hash().
The above can cause OoO for unconnected IPv6 UDPv6 socket: in that
scenario the egress tx queue can be selected on a per packet basis
via the skb hash.
It may also fool flow-oriented schedulers to place fragments belonging
to the same datagram in different flows.

Fix the issue by copying the skb hash from the head frag into
the others at fragmentation time.

Before this commit:
perf probe -a "dev_queue_xmit skb skb->hash skb->l4_hash:b1@0/8 skb->sw_hash:b1@1/8"
netperf -H $IPV4 -t UDP_STREAM -l 5 -- -m 2000 -n &
perf record -e probe:dev_queue_xmit -e probe:skb_set_owner_w -a sleep 0.1
perf script
probe:dev_queue_xmit: (ffffffff8c6b1b20) hash=3713014309 l4_hash=1 sw_hash=0
probe:dev_queue_xmit: (ffffffff8c6b1b20) hash=0 l4_hash=0 sw_hash=0

After this commit:
probe:dev_queue_xmit: (ffffffff8c6b1b20) hash=2171763177 l4_hash=1 sw_hash=0
probe:dev_queue_xmit: (ffffffff8c6b1b20) hash=2171763177 l4_hash=1 sw_hash=0

Fixes: b73c3d0e4f ("net: Save TX flow hash in sock and set in skbuf on xmit")
Fixes: 67800f9b1f ("ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28 07:49:11 +02:00
2ea8b93c03 xprtrdma: Return -ENOBUFS when no pages are available
commit a8f688ec43 upstream.

The use of -EAGAIN in rpcrdma_convert_iovs() is a latent bug: the
transport never calls xprt_write_space() when more pages become
available. -ENOBUFS will trigger the correct "delay briefly and call
again" logic.

Fixes: 7a89f9c626 ("xprtrdma: Honor ->send_request API contract")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25 11:24:02 +02:00
ad375eae79 skbuff: Unconditionally copy pfmemalloc in __skb_clone()
[ Upstream commit e78bfb0751 ]

Commit 8b7008620b ("net: Don't copy pfmemalloc flag in
__copy_skb_header()") introduced a different handling for the
pfmemalloc flag in copy and clone paths.

In __skb_clone(), now, the flag is set only if it was set in the
original skb, but not cleared if it wasn't. This is wrong and
might lead to socket buffers being flagged with pfmemalloc even
if the skb data wasn't allocated from pfmemalloc reserves. Copy
the flag instead of ORing it.

Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Fixes: 8b7008620b ("net: Don't copy pfmemalloc flag in __copy_skb_header()")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Tested-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25 11:24:02 +02:00
cad99229aa net: Don't copy pfmemalloc flag in __copy_skb_header()
[ Upstream commit 8b7008620b ]

The pfmemalloc flag indicates that the skb was allocated from
the PFMEMALLOC reserves, and the flag is currently copied on skb
copy and clone.

However, an skb copied from an skb flagged with pfmemalloc
wasn't necessarily allocated from PFMEMALLOC reserves, and on
the other hand an skb allocated that way might be copied from an
skb that wasn't.

So we should not copy the flag on skb copy, and rather decide
whether to allow an skb to be associated with sockets unrelated
to page reclaim depending only on how it was allocated.

Move the pfmemalloc flag before headers_start[0] using an
existing 1-bit hole, so that __copy_skb_header() doesn't copy
it.

When cloning, we'll now take care of this flag explicitly,
contravening to the warning comment of __skb_clone().

While at it, restore the newline usage introduced by commit
b193722731 ("net: reorganize sk_buff for faster
__copy_skb_header()") to visually separate bytes used in
bitfields after headers_start[0], that was gone after commit
a9e419dc7b ("netfilter: merge ctinfo into nfct pointer storage
area"), and describe the pfmemalloc flag in the kernel-doc
structure comment.

This doesn't change the size of sk_buff or cacheline boundaries,
but consolidates the 15 bits hole before tc_index into a 2 bytes
hole before csum, that could now be filled more easily.

Reported-by: Patrick Talbert <ptalbert@redhat.com>
Fixes: c93bdd0e03 ("netvm: allow skb allocation to use PFMEMALLOC reserves")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25 11:24:02 +02:00
f08ca4c8b4 net/ipv4: Set oif in fib_compute_spec_dst
[ Upstream commit e7372197e1 ]

Xin reported that icmp replies may not use the address on the device the
echo request is received if the destination address is broadcast. Instead
a route lookup is done without considering VRF context. Fix by setting
oif in flow struct to the master device if it is enslaved. That directs
the lookup to the VRF table. If the device is not enslaved, oif is still
0 so no affect.

Fixes: cd2fbe1b6b ("net: Use VRF device index for lookups on RX")
Reported-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25 11:24:01 +02:00
66a7cfa057 net: diag: Don't double-free TCP_NEW_SYN_RECV sockets in tcp_abort
[ Upstream commit acc2cf4e37 ]

When tcp_diag_destroy closes a TCP_NEW_SYN_RECV socket, it first
frees it by calling inet_csk_reqsk_queue_drop_and_and_put in
tcp_abort, and then frees it again by calling sock_gen_put.

Since tcp_abort only has one caller, and all the other codepaths
in tcp_abort don't free the socket, just remove the free in that
function.

Cc: David Ahern <dsa@cumulusnetworks.com>
Tested: passes Android sock_diag_test.py, which exercises this codepath
Fixes: d7226c7a4d ("net: diag: Fix refcnt leak in error path destroying socket")
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsa@cumulusnetworks.com>
Tested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25 11:24:01 +02:00
79870c6c65 ipv4: Return EINVAL when ping_group_range sysctl doesn't map to user ns
[ Upstream commit 70ba5b6db9 ]

The low and high values of the net.ipv4.ping_group_range sysctl were
being silently forced to the default disabled state when a write to the
sysctl contained GIDs that didn't map to the associated user namespace.
Confusingly, the sysctl's write operation would return success and then
a subsequent read of the sysctl would indicate that the low and high
values are the overflowgid.

This patch changes the behavior by clearly returning an error when the
sysctl write operation receives a GID range that doesn't map to the
associated user namespace. In such a situation, the previous value of
the sysctl is preserved and that range will be returned in a subsequent
read of the sysctl.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25 11:24:00 +02:00
ec6a6039d7 gen_stats: Fix netlink stats dumping in the presence of padding
[ Upstream commit d5a672ac9f ]

The gen_stats facility will add a header for the toplevel nlattr of type
TCA_STATS2 that contains all stats added by qdisc callbacks. A reference
to this header is stored in the gnet_dump struct, and when all the
per-qdisc callbacks have finished adding their stats, the length of the
containing header will be adjusted to the right value.

However, on architectures that need padding (i.e., that don't set
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS), the padding nlattr is added
before the stats, which means that the stored pointer will point to the
padding, and so when the header is fixed up, the result is just a very
big padding nlattr. Because most qdiscs also supply the legacy TCA_STATS
struct, this problem has been mostly invisible, but we exposed it with
the netlink attribute-based statistics in CAKE.

Fix the issue by fixing up the stored pointer if it points to a padding
nlattr.

Tested-by: Pete Heist <pete@heistp.net>
Tested-by: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25 11:24:00 +02:00
d31a56d23e net/nfc: Avoid stalls when nfc_alloc_send_skb() returned NULL.
commit 3bc53be9db upstream.

syzbot is reporting stalls at nfc_llcp_send_ui_frame() [1]. This is
because nfc_llcp_send_ui_frame() is retrying the loop without any delay
when nonblocking nfc_alloc_send_skb() returned NULL.

Since there is no need to use MSG_DONTWAIT if we retry until
sock_alloc_send_pskb() succeeds, let's use blocking call.
Also, in case an unexpected error occurred, let's break the loop
if blocking nfc_alloc_send_skb() failed.

[1] https://syzkaller.appspot.com/bug?id=4a131cc571c3733e0eff6bc673f4e36ae48f19c6

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+d29d18215e477cfbfbdd@syzkaller.appspotmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-22 14:27:40 +02:00
863d5568b7 rds: avoid unenecessary cong_update in loop transport
commit f1693c63ab upstream.

Loop transport which is self loopback, remote port congestion
update isn't relevant. Infact the xmit path already ignores it.
Receive path needs to do the same.

Reported-by: syzbot+4c20b3866171ce8441d2@syzkaller.appspotmail.com
Reviewed-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-22 14:27:39 +02:00
ad8b1ffc3e netfilter: ipv6: nf_defrag: drop skb dst before queueing
commit 84379c9afe upstream.

Eric Dumazet reports:
 Here is a reproducer of an annoying bug detected by syzkaller on our production kernel
 [..]
 ./b78305423 enable_conntrack
 Then :
 sleep 60
 dmesg | tail -10
 [  171.599093] unregister_netdevice: waiting for lo to become free. Usage count = 2
 [  181.631024] unregister_netdevice: waiting for lo to become free. Usage count = 2
 [  191.687076] unregister_netdevice: waiting for lo to become free. Usage count = 2
 [  201.703037] unregister_netdevice: waiting for lo to become free. Usage count = 2
 [  211.711072] unregister_netdevice: waiting for lo to become free. Usage count = 2
 [  221.959070] unregister_netdevice: waiting for lo to become free. Usage count = 2

Reproducer sends ipv6 fragment that hits nfct defrag via LOCAL_OUT hook.
skb gets queued until frag timer expiry -- 1 minute.

Normally nf_conntrack_reasm gets called during prerouting, so skb has
no dst yet which might explain why this wasn't spotted earlier.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Reported-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Tested-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-22 14:27:39 +02:00
3d0ce44daf KEYS: DNS: fix parsing multiple options
commit c604cb7670 upstream.

My recent fix for dns_resolver_preparse() printing very long strings was
incomplete, as shown by syzbot which still managed to hit the
WARN_ONCE() in set_precision() by adding a crafted "dns_resolver" key:

    precision 50001 too large
    WARNING: CPU: 7 PID: 864 at lib/vsprintf.c:2164 vsnprintf+0x48a/0x5a0

The bug this time isn't just a printing bug, but also a logical error
when multiple options ("#"-separated strings) are given in the key
payload.  Specifically, when separating an option string into name and
value, if there is no value then the name is incorrectly considered to
end at the end of the key payload, rather than the end of the current
option.  This bypasses validation of the option length, and also means
that specifying multiple options is broken -- which presumably has gone
unnoticed as there is currently only one valid option anyway.

A similar problem also applied to option values, as the kstrtoul() when
parsing the "dnserror" option will read past the end of the current
option and into the next option.

Fix these bugs by correctly computing the length of the option name and
by copying the option value, null-terminated, into a temporary buffer.

Reproducer for the WARN_ONCE() that syzbot hit:

    perl -e 'print "#A#", "\0" x 50000' | keyctl padd dns_resolver desc @s

Reproducer for "dnserror" option being parsed incorrectly (expected
behavior is to fail when seeing the unknown option "foo", actual
behavior was to read the dnserror value as "1#foo" and fail there):

    perl -e 'print "#dnserror=1#foo\0"' | keyctl padd dns_resolver desc @s

Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 4a2d789267 ("DNS: If the DNS server returns an error, allow that to be cached [ver #2]")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-22 14:27:39 +02:00
064d9e9744 netfilter: ebtables: reject non-bridge targets
commit 11ff7288be upstream.

the ebtables evaluation loop expects targets to return
positive values (jumps), or negative values (absolute verdicts).

This is completely different from what xtables does.
In xtables, targets are expected to return the standard netfilter
verdicts, i.e. NF_DROP, NF_ACCEPT, etc.

ebtables will consider these as jumps.

Therefore reject any target found due to unspec fallback.
v2: also reject watchers.  ebtables ignores their return value, so
a target that assumes skb ownership (and returns NF_STOLEN) causes
use-after-free.

The only watchers in the 'ebtables' front-end are log and nflog;
both have AF_BRIDGE specific wrappers on kernel side.

Reported-by: syzbot+2b43f681169a2a0d306a@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-22 14:27:39 +02:00
9dc96f7205 net/packet: fix use-after-free
[ Upstream commit 945d015ee0 ]

We should put copy_skb in receive_queue only after
a successful call to virtio_net_hdr_from_skb().

syzbot report :

BUG: KASAN: use-after-free in __skb_unlink include/linux/skbuff.h:1843 [inline]
BUG: KASAN: use-after-free in __skb_dequeue include/linux/skbuff.h:1863 [inline]
BUG: KASAN: use-after-free in skb_dequeue+0x16a/0x180 net/core/skbuff.c:2815
Read of size 8 at addr ffff8801b044ecc0 by task syz-executor217/4553

CPU: 0 PID: 4553 Comm: syz-executor217 Not tainted 4.18.0-rc1+ #111
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 __skb_unlink include/linux/skbuff.h:1843 [inline]
 __skb_dequeue include/linux/skbuff.h:1863 [inline]
 skb_dequeue+0x16a/0x180 net/core/skbuff.c:2815
 skb_queue_purge+0x26/0x40 net/core/skbuff.c:2852
 packet_set_ring+0x675/0x1da0 net/packet/af_packet.c:4331
 packet_release+0x630/0xd90 net/packet/af_packet.c:2991
 __sock_release+0xd7/0x260 net/socket.c:603
 sock_close+0x19/0x20 net/socket.c:1186
 __fput+0x35b/0x8b0 fs/file_table.c:209
 ____fput+0x15/0x20 fs/file_table.c:243
 task_work_run+0x1ec/0x2a0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x1b08/0x2750 kernel/exit.c:865
 do_group_exit+0x177/0x440 kernel/exit.c:968
 __do_sys_exit_group kernel/exit.c:979 [inline]
 __se_sys_exit_group kernel/exit.c:977 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:977
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4448e9
Code: Bad RIP value.
RSP: 002b:00007ffd5f777ca8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004448e9
RDX: 00000000004448e9 RSI: 000000000000fcfb RDI: 0000000000000001
RBP: 00000000006cf018 R08: 00007ffd0000a45b R09: 0000000000000000
R10: 00007ffd5f777e48 R11: 0000000000000202 R12: 00000000004021f0
R13: 0000000000402280 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4553:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554
 skb_clone+0x1f5/0x500 net/core/skbuff.c:1282
 tpacket_rcv+0x28f7/0x3200 net/packet/af_packet.c:2221
 deliver_skb net/core/dev.c:1925 [inline]
 deliver_ptype_list_skb net/core/dev.c:1940 [inline]
 __netif_receive_skb_core+0x1bfb/0x3680 net/core/dev.c:4611
 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4693
 netif_receive_skb_internal+0x12e/0x7d0 net/core/dev.c:4767
 netif_receive_skb+0xbf/0x420 net/core/dev.c:4791
 tun_rx_batched.isra.55+0x4ba/0x8c0 drivers/net/tun.c:1571
 tun_get_user+0x2af1/0x42f0 drivers/net/tun.c:1981
 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:2009
 call_write_iter include/linux/fs.h:1795 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x6c6/0x9f0 fs/read_write.c:487
 vfs_write+0x1f8/0x560 fs/read_write.c:549
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 4553:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x86/0x2d0 mm/slab.c:3756
 kfree_skbmem+0x154/0x230 net/core/skbuff.c:582
 __kfree_skb net/core/skbuff.c:642 [inline]
 kfree_skb+0x1a5/0x580 net/core/skbuff.c:659
 tpacket_rcv+0x189e/0x3200 net/packet/af_packet.c:2385
 deliver_skb net/core/dev.c:1925 [inline]
 deliver_ptype_list_skb net/core/dev.c:1940 [inline]
 __netif_receive_skb_core+0x1bfb/0x3680 net/core/dev.c:4611
 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4693
 netif_receive_skb_internal+0x12e/0x7d0 net/core/dev.c:4767
 netif_receive_skb+0xbf/0x420 net/core/dev.c:4791
 tun_rx_batched.isra.55+0x4ba/0x8c0 drivers/net/tun.c:1571
 tun_get_user+0x2af1/0x42f0 drivers/net/tun.c:1981
 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:2009
 call_write_iter include/linux/fs.h:1795 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x6c6/0x9f0 fs/read_write.c:487
 vfs_write+0x1f8/0x560 fs/read_write.c:549
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801b044ecc0
 which belongs to the cache skbuff_head_cache of size 232
The buggy address is located 0 bytes inside of
 232-byte region [ffff8801b044ecc0, ffff8801b044eda8)
The buggy address belongs to the page:
page:ffffea0006c11380 count:1 mapcount:0 mapping:ffff8801d9be96c0 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0006c17988 ffff8801d9bec248 ffff8801d9be96c0
raw: 0000000000000000 ffff8801b044e040 000000010000000c 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801b044eb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b044ec00: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc
>ffff8801b044ec80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                           ^
 ffff8801b044ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801b044ed80: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc

Fixes: 58d19b19cd ("packet: vnet_hdr support for tpacket_rcv")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-22 14:27:38 +02:00
65fb77c3ba tcp: prevent bogus FRTO undos with non-SACK flows
[ Upstream commit 1236f22fba ]

If SACK is not enabled and the first cumulative ACK after the RTO
retransmission covers more than the retransmitted skb, a spurious
FRTO undo will trigger (assuming FRTO is enabled for that RTO).
The reason is that any non-retransmitted segment acknowledged will
set FLAG_ORIG_SACK_ACKED in tcp_clean_rtx_queue even if there is
no indication that it would have been delivered for real (the
scoreboard is not kept with TCPCB_SACKED_ACKED bits in the non-SACK
case so the check for that bit won't help like it does with SACK).
Having FLAG_ORIG_SACK_ACKED set results in the spurious FRTO undo
in tcp_process_loss.

We need to use more strict condition for non-SACK case and check
that none of the cumulatively ACKed segments were retransmitted
to prove that progress is due to original transmissions. Only then
keep FLAG_ORIG_SACK_ACKED set, allowing FRTO undo to proceed in
non-SACK case.

(FLAG_ORIG_SACK_ACKED is planned to be renamed to FLAG_ORIG_PROGRESS
to better indicate its purpose but to keep this change minimal, it
will be done in another patch).

Besides burstiness and congestion control violations, this problem
can result in RTO loop: When the loss recovery is prematurely
undoed, only new data will be transmitted (if available) and
the next retransmission can occur only after a new RTO which in case
of multiple losses (that are not for consecutive packets) requires
one RTO per loss to recover.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Tested-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-22 14:27:37 +02:00
63253726a5 tcp: fix Fast Open key endianness
[ Upstream commit c860e997e9 ]

Fast Open key could be stored in different endian based on the CPU.
Previously hosts in different endianness in a server farm using
the same key config (sysctl value) would produce different cookies.
This patch fixes it by always storing it as little endian to keep
same API for LE hosts.

Reported-by: Daniele Iamartino <danielei@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-22 14:27:37 +02:00
1f1fbe1692 net_sched: blackhole: tell upper qdisc about dropped packets
[ Upstream commit 7e85dc8cb3 ]

When blackhole is used on top of classful qdisc like hfsc it breaks
qlen and backlog counters because packets are disappear without notice.

In HFSC non-zero qlen while all classes are inactive triggers warning:
WARNING: ... at net/sched/sch_hfsc.c:1393 hfsc_dequeue+0xba4/0xe90 [sch_hfsc]
and schedules watchdog work endlessly.

This patch return __NET_XMIT_BYPASS in addition to NET_XMIT_SUCCESS,
this flag tells upper layer: this packet is gone and isn't queued.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-22 14:27:36 +02:00
e555ae018b net: dccp: switch rx_tstamp_last_feedback to monotonic clock
[ Upstream commit 0ce4e70ff0 ]

To compute delays, better not use time of the day which can
be changed by admins or malicious programs.

Also change ccid3_first_li() to use s64 type for delta variable
to avoid potential overflows.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Cc: dccp@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-22 14:27:36 +02:00
87cd5e4acd net: dccp: avoid crash in ccid3_hc_rx_send_feedback()
[ Upstream commit 74174fe563 ]

On fast hosts or malicious bots, we trigger a DCCP_BUG() which
seems excessive.

syzbot reported :

BUG: delta (-6195) <= 0 at net/dccp/ccids/ccid3.c:628/ccid3_hc_rx_send_feedback()
CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 4.18.0-rc1+ #112
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 ccid3_hc_rx_send_feedback net/dccp/ccids/ccid3.c:628 [inline]
 ccid3_hc_rx_packet_recv.cold.16+0x38/0x71 net/dccp/ccids/ccid3.c:793
 ccid_hc_rx_packet_recv net/dccp/ccid.h:185 [inline]
 dccp_deliver_input_to_ccids+0xf0/0x280 net/dccp/input.c:180
 dccp_rcv_established+0x87/0xb0 net/dccp/input.c:378
 dccp_v4_do_rcv+0x153/0x180 net/dccp/ipv4.c:654
 sk_backlog_rcv include/net/sock.h:914 [inline]
 __sk_receive_skb+0x3ba/0xd80 net/core/sock.c:517
 dccp_v4_rcv+0x10f9/0x1f58 net/dccp/ipv4.c:875
 ip_local_deliver_finish+0x2eb/0xda0 net/ipv4/ip_input.c:215
 NF_HOOK include/linux/netfilter.h:287 [inline]
 ip_local_deliver+0x1e9/0x750 net/ipv4/ip_input.c:256
 dst_input include/net/dst.h:450 [inline]
 ip_rcv_finish+0x823/0x2220 net/ipv4/ip_input.c:396
 NF_HOOK include/linux/netfilter.h:287 [inline]
 ip_rcv+0xa18/0x1284 net/ipv4/ip_input.c:492
 __netif_receive_skb_core+0x2488/0x3680 net/core/dev.c:4628
 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4693
 process_backlog+0x219/0x760 net/core/dev.c:5373
 napi_poll net/core/dev.c:5771 [inline]
 net_rx_action+0x7da/0x1980 net/core/dev.c:5837
 __do_softirq+0x2e8/0xb17 kernel/softirq.c:284
 run_ksoftirqd+0x86/0x100 kernel/softirq.c:645
 smpboot_thread_fn+0x417/0x870 kernel/smpboot.c:164
 kthread+0x345/0x410 kernel/kthread.c:240
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Cc: dccp@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-22 14:27:36 +02:00
40352e791c netfilter: x_tables: initialise match/target check parameter struct
commit c568503ef0 upstream.

syzbot reports following splat:

BUG: KMSAN: uninit-value in ebt_stp_mt_check+0x24b/0x450
 net/bridge/netfilter/ebt_stp.c:162
 ebt_stp_mt_check+0x24b/0x450 net/bridge/netfilter/ebt_stp.c:162
 xt_check_match+0x1438/0x1650 net/netfilter/x_tables.c:506
 ebt_check_match net/bridge/netfilter/ebtables.c:372 [inline]
 ebt_check_entry net/bridge/netfilter/ebtables.c:702 [inline]

The uninitialised access is
   xt_mtchk_param->nft_compat

... which should be set to 0.
Fix it by zeroing the struct beforehand, same for tgchk.

ip(6)tables targetinfo uses c99-style initialiser, so no change
needed there.

Reported-by: syzbot+da4494182233c23a5fcf@syzkaller.appspotmail.com
Fixes: 55917a21d0 ("netfilter: x_tables: add context to know if extension runs from nft_compat")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-17 11:37:54 +02:00