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Author SHA1 Message Date
Greg Kroah-Hartman
62872f952d This is the 4.4.174 stable release
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Merge 4.4.174 into android-4.4

Changes in 4.4.174
	inet: frags: change inet_frags_init_net() return value
	inet: frags: add a pointer to struct netns_frags
	inet: frags: refactor ipfrag_init()
	inet: frags: refactor ipv6_frag_init()
	inet: frags: refactor lowpan_net_frag_init()
	rhashtable: add rhashtable_lookup_get_insert_key()
	rhashtable: Add rhashtable_lookup()
	rhashtable: add schedule points
	inet: frags: use rhashtables for reassembly units
	net: ieee802154: 6lowpan: fix frag reassembly
	ipfrag: really prevent allocation on netns exit
	inet: frags: remove some helpers
	inet: frags: get rif of inet_frag_evicting()
	inet: frags: remove inet_frag_maybe_warn_overflow()
	inet: frags: break the 2GB limit for frags storage
	inet: frags: do not clone skb in ip_expire()
	ipv6: frags: rewrite ip6_expire_frag_queue()
	rhashtable: reorganize struct rhashtable layout
	inet: frags: reorganize struct netns_frags
	inet: frags: get rid of ipfrag_skb_cb/FRAG_CB
	inet: frags: fix ip6frag_low_thresh boundary
	ip: discard IPv4 datagrams with overlapping segments.
	net: modify skb_rbtree_purge to return the truesize of all purged skbs.
	ipv6: defrag: drop non-last frags smaller than min mtu
	net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends
	ip: use rb trees for IP frag queue.
	ip: add helpers to process in-order fragments faster.
	ip: process in-order fragments efficiently
	ip: frags: fix crash in ip_do_fragment()
	ipv4: frags: precedence bug in ip_expire()
	inet: frags: better deal with smp races
	net: fix pskb_trim_rcsum_slow() with odd trim offset
	net: ipv4: do not handle duplicate fragments as overlapping
	rcu: Force boolean subscript for expedited stall warnings
	Linux 4.4.174

Change-Id: I47eace4f47ffe0bf16b29615d09ed903c40a272b
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-02-08 11:47:29 +01:00
Greg Kroah-Hartman
dc5e8c9997 Linux 4.4.174 2019-02-08 11:25:33 +01:00
Paul E. McKenney
60c7f8fca1 rcu: Force boolean subscript for expedited stall warnings
commit ec3833ed02ae6ef2a933ece9de7cbab0c64c699e upstream.

The cpu_online() function can return values other than 0 and 1, which
can result in subscript overflow when applied to a two-element array.
This commit allows for this behavior by using "!!" on the return value
from cpu_online() when used as a subscript.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: "Rantala, Tommi" <tommi.t.rantala@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:33 +01:00
Michal Kubecek
873beab374 net: ipv4: do not handle duplicate fragments as overlapping
commit ade446403bfb79d3528d56071a84b15351a139ad upstream.

Since commit 7969e5c40dfd ("ip: discard IPv4 datagrams with overlapping
segments.") IPv4 reassembly code drops the whole queue whenever an
overlapping fragment is received. However, the test is written in a way
which detects duplicate fragments as overlapping so that in environments
with many duplicate packets, fragmented packets may be undeliverable.

Add an extra test and for (potentially) duplicate fragment, only drop the
new fragment rather than the whole queue. Only starting offset and length
are checked, not the contents of the fragments as that would be too
expensive. For similar reason, linear list ("run") of a rbtree node is not
iterated, we only check if the new fragment is a subset of the interval
covered by existing consecutive fragments.

v2: instead of an exact check iterating through linear list of an rbtree
node, only check if the new fragment is subset of the "run" (suggested
by Eric Dumazet)

Fixes: 7969e5c40dfd ("ip: discard IPv4 datagrams with overlapping segments.")
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
[bwh: Backported to 4.4:
 - goto discard_qp, not err, in case of overlap
 - Set err earlier variable, as done upstream in commit 0ff89efb5246
   "ip: fail fast on IP defrag errors"]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:33 +01:00
Dimitris Michailidis
0836bdfee5 net: fix pskb_trim_rcsum_slow() with odd trim offset
commit d55bef5059dd057bd077155375c581b49d25be7e upstream.

We've been getting checksum errors involving small UDP packets, usually
59B packets with 1 extra non-zero padding byte. netdev_rx_csum_fault()
has been complaining that HW is providing bad checksums. Turns out the
problem is in pskb_trim_rcsum_slow(), introduced in commit 88078d98d1bb
("net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends").

The source of the problem is that when the bytes we are trimming start
at an odd address, as in the case of the 1 padding byte above,
skb_checksum() returns a byte-swapped value. We cannot just combine this
with skb->csum using csum_sub(). We need to use csum_block_sub() here
that takes into account the parity of the start address and handles the
swapping.

Matches existing code in __skb_postpull_rcsum() and esp_remove_trailer().

Fixes: 88078d98d1bb ("net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends")
Signed-off-by: Dimitris Michailidis <dmichail@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:33 +01:00
Eric Dumazet
e92b8475d6 inet: frags: better deal with smp races
commit 0d5b9311baf27bb545f187f12ecfd558220c607d upstream.

Multiple cpus might attempt to insert a new fragment in rhashtable,
if for example RPS is buggy, as reported by 배석진 in
https://patchwork.ozlabs.org/patch/994601/

We use rhashtable_lookup_get_insert_key() instead of
rhashtable_insert_fast() to let cpus losing the race
free their own inet_frag_queue and use the one that
was inserted by another cpu.

Fixes: 648700f76b03 ("inet: frags: use rhashtables for reassembly units")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: 배석진 <soukjin.bae@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:33 +01:00
Dan Carpenter
acd00a0692 ipv4: frags: precedence bug in ip_expire()
commit 70837ffe3085c9a91488b52ca13ac84424da1042 upstream.

We accidentally removed the parentheses here, but they are required
because '!' has higher precedence than '&'.

Fixes: fa0f527358bd ("ip: use rb trees for IP frag queue.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:33 +01:00
Taehee Yoo
cb5fd4aa24 ip: frags: fix crash in ip_do_fragment()
commit 5d407b071dc369c26a38398326ee2be53651cfe4 upstream.

A kernel crash occurrs when defragmented packet is fragmented
in ip_do_fragment().
In defragment routine, skb_orphan() is called and
skb->ip_defrag_offset is set. but skb->sk and
skb->ip_defrag_offset are same union member. so that
frag->sk is not NULL.
Hence crash occurrs in skb->sk check routine in ip_do_fragment() when
defragmented packet is fragmented.

test commands:
   %iptables -t nat -I POSTROUTING -j MASQUERADE
   %hping3 192.168.4.2 -s 1000 -p 2000 -d 60000

splat looks like:
[  261.069429] kernel BUG at net/ipv4/ip_output.c:636!
[  261.075753] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[  261.083854] CPU: 1 PID: 1349 Comm: hping3 Not tainted 4.19.0-rc2+ #3
[  261.100977] RIP: 0010:ip_do_fragment+0x1613/0x2600
[  261.106945] Code: e8 e2 38 e3 fe 4c 8b 44 24 18 48 8b 74 24 08 e9 92 f6 ff ff 80 3c 02 00 0f 85 da 07 00 00 48 8b b5 d0 00 00 00 e9 25 f6 ff ff <0f> 0b 0f 0b 44 8b 54 24 58 4c 8b 4c 24 18 4c 8b 5c 24 60 4c 8b 6c
[  261.127015] RSP: 0018:ffff8801031cf2c0 EFLAGS: 00010202
[  261.134156] RAX: 1ffff1002297537b RBX: ffffed0020639e6e RCX: 0000000000000004
[  261.142156] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880114ba9bd8
[  261.150157] RBP: ffff880114ba8a40 R08: ffffed0022975395 R09: ffffed0022975395
[  261.158157] R10: 0000000000000001 R11: ffffed0022975394 R12: ffff880114ba9ca4
[  261.166159] R13: 0000000000000010 R14: ffff880114ba9bc0 R15: dffffc0000000000
[  261.174169] FS:  00007fbae2199700(0000) GS:ffff88011b400000(0000) knlGS:0000000000000000
[  261.183012] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  261.189013] CR2: 00005579244fe000 CR3: 0000000119bf4000 CR4: 00000000001006e0
[  261.198158] Call Trace:
[  261.199018]  ? dst_output+0x180/0x180
[  261.205011]  ? save_trace+0x300/0x300
[  261.209018]  ? ip_copy_metadata+0xb00/0xb00
[  261.213034]  ? sched_clock_local+0xd4/0x140
[  261.218158]  ? kill_l4proto+0x120/0x120 [nf_conntrack]
[  261.223014]  ? rt_cpu_seq_stop+0x10/0x10
[  261.227014]  ? find_held_lock+0x39/0x1c0
[  261.233008]  ip_finish_output+0x51d/0xb50
[  261.237006]  ? ip_fragment.constprop.56+0x220/0x220
[  261.243011]  ? nf_ct_l4proto_register_one+0x5b0/0x5b0 [nf_conntrack]
[  261.250152]  ? rcu_is_watching+0x77/0x120
[  261.255010]  ? nf_nat_ipv4_out+0x1e/0x2b0 [nf_nat_ipv4]
[  261.261033]  ? nf_hook_slow+0xb1/0x160
[  261.265007]  ip_output+0x1c7/0x710
[  261.269005]  ? ip_mc_output+0x13f0/0x13f0
[  261.273002]  ? __local_bh_enable_ip+0xe9/0x1b0
[  261.278152]  ? ip_fragment.constprop.56+0x220/0x220
[  261.282996]  ? nf_hook_slow+0xb1/0x160
[  261.287007]  raw_sendmsg+0x21f9/0x4420
[  261.291008]  ? dst_output+0x180/0x180
[  261.297003]  ? sched_clock_cpu+0x126/0x170
[  261.301003]  ? find_held_lock+0x39/0x1c0
[  261.306155]  ? stop_critical_timings+0x420/0x420
[  261.311004]  ? check_flags.part.36+0x450/0x450
[  261.315005]  ? _raw_spin_unlock_irq+0x29/0x40
[  261.320995]  ? _raw_spin_unlock_irq+0x29/0x40
[  261.326142]  ? cyc2ns_read_end+0x10/0x10
[  261.330139]  ? raw_bind+0x280/0x280
[  261.334138]  ? sched_clock_cpu+0x126/0x170
[  261.338995]  ? check_flags.part.36+0x450/0x450
[  261.342991]  ? __lock_acquire+0x4500/0x4500
[  261.348994]  ? inet_sendmsg+0x11c/0x500
[  261.352989]  ? dst_output+0x180/0x180
[  261.357012]  inet_sendmsg+0x11c/0x500
[ ... ]

v2:
 - clear skb->sk at reassembly routine.(Eric Dumarzet)

Fixes: fa0f527358bd ("ip: use rb trees for IP frag queue.")
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:33 +01:00
Peter Oskolkov
2822475e70 ip: process in-order fragments efficiently
commit a4fd284a1f8fd4b6c59aa59db2185b1e17c5c11c upstream.

This patch changes the runtime behavior of IP defrag queue:
incoming in-order fragments are added to the end of the current
list/"run" of in-order fragments at the tail.

On some workloads, UDP stream performance is substantially improved:

RX: ./udp_stream -F 10 -T 2 -l 60
TX: ./udp_stream -c -H <host> -F 10 -T 5 -l 60

with this patchset applied on a 10Gbps receiver:

  throughput=9524.18
  throughput_units=Mbit/s

upstream (net-next):

  throughput=4608.93
  throughput_units=Mbit/s

Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:33 +01:00
Peter Oskolkov
2039bd8669 ip: add helpers to process in-order fragments faster.
commit 353c9cb360874e737fb000545f783df756c06f9a upstream.

This patch introduces several helper functions/macros that will be
used in the follow-up patch. No runtime changes yet.

The new logic (fully implemented in the second patch) is as follows:

* Nodes in the rb-tree will now contain not single fragments, but lists
  of consecutive fragments ("runs").

* At each point in time, the current "active" run at the tail is
  maintained/tracked. Fragments that arrive in-order, adjacent
  to the previous tail fragment, are added to this tail run without
  triggering the re-balancing of the rb-tree.

* If a fragment arrives out of order with the offset _before_ the tail run,
  it is inserted into the rb-tree as a single fragment.

* If a fragment arrives after the current tail fragment (with a gap),
  it starts a new "tail" run, as is inserted into the rb-tree
  at the end as the head of the new run.

skb->cb is used to store additional information
needed here (suggested by Eric Dumazet).

Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:32 +01:00
Peter Oskolkov
3f78a3f45e ip: use rb trees for IP frag queue.
commit fa0f527358bd900ef92f925878ed6bfbd51305cc upstream.

Similar to TCP OOO RX queue, it makes sense to use rb trees to store
IP fragments, so that OOO fragments are inserted faster.

Tested:

- a follow-up patch contains a rather comprehensive ip defrag
  self-test (functional)
- ran neper `udp_stream -c -H <host> -F 100 -l 300 -T 20`:
    netstat --statistics
    Ip:
        282078937 total packets received
        0 forwarded
        0 incoming packets discarded
        946760 incoming packets delivered
        18743456 requests sent out
        101 fragments dropped after timeout
        282077129 reassemblies required
        944952 packets reassembled ok
        262734239 packet reassembles failed
   (The numbers/stats above are somewhat better re:
    reassemblies vs a kernel without this patchset. More
    comprehensive performance testing TBD).

Reported-by: Jann Horn <jannh@google.com>
Reported-by: Juha-Matti Tilli <juha-matti.tilli@iki.fi>
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
[bwh: Backported to 4.4:
 - Keep using frag_kfree_skb() in inet_frag_destroy()
 - Adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:32 +01:00
Eric Dumazet
7fab8b2f0c net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends
commit 88078d98d1bb085d72af8437707279e203524fa5 upstream.

After working on IP defragmentation lately, I found that some large
packets defeat CHECKSUM_COMPLETE optimization because of NIC adding
zero paddings on the last (small) fragment.

While removing the padding with pskb_trim_rcsum(), we set skb->ip_summed
to CHECKSUM_NONE, forcing a full csum validation, even if all prior
fragments had CHECKSUM_COMPLETE set.

We can instead compute the checksum of the part we are trimming,
usually smaller than the part we keep.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:32 +01:00
Florian Westphal
5f2d68b6b5 ipv6: defrag: drop non-last frags smaller than min mtu
commit 0ed4229b08c13c84a3c301a08defdc9e7f4467e6 upstream.

don't bother with pathological cases, they only waste cycles.
IPv6 requires a minimum MTU of 1280 so we should never see fragments
smaller than this (except last frag).

v3: don't use awkward "-offset + len"
v2: drop IPv4 part, which added same check w. IPV4_MIN_MTU (68).
    There were concerns that there could be even smaller frags
    generated by intermediate nodes, e.g. on radio networks.

Cc: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
[bwh: Backported to 4.4: In nf_ct_frag6_gather() use clone instead of skb,
 and goto ret_orig in case of error]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:32 +01:00
Peter Oskolkov
26cfea3c1d net: modify skb_rbtree_purge to return the truesize of all purged skbs.
commit 385114dec8a49b5e5945e77ba7de6356106713f4 upstream.

Tested: see the next patch is the series.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:32 +01:00
Peter Oskolkov
ef0f963de1 ip: discard IPv4 datagrams with overlapping segments.
commit 7969e5c40dfd04799d4341f1b7cd266b6e47f227 upstream.

This behavior is required in IPv6, and there is little need
to tolerate overlapping fragments in IPv4. This change
simplifies the code and eliminates potential DDoS attack vectors.

Tested: ran ip_defrag selftest (not yet available uptream).

Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
[bwh: Backported to 4.4:
 - s/__IP_INC_STATS/IP_INC_STATS_BH/
 - Deleted code is slightly different]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:32 +01:00
Eric Dumazet
bf40801a01 inet: frags: fix ip6frag_low_thresh boundary
commit 3d23401283e80ceb03f765842787e0e79ff598b7 upstream.

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: 6e00f7dd5e4e ("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>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:32 +01:00
Eric Dumazet
826ff79914 inet: frags: get rid of ipfrag_skb_cb/FRAG_CB
commit bf66337140c64c27fa37222b7abca7e49d63fb57 upstream.

ip_defrag uses skb->cb[] to store the fragment offset, and unfortunately
this integer is currently in a different cache line than skb->next,
meaning that we use two cache lines per skb when finding the insertion point.

By aliasing skb->ip_defrag_offset and skb->dev, we pack all the fields
in a single cache line and save precious memory bandwidth.

Note that after the fast path added by Changli Gao in commit
d6bebca92c ("fragment: add fast path for in-order fragments")
this change wont help the fast path, since we still need
to access prev->len (2nd cache line), but will show great
benefits when slow path is entered, since we perform
a linear scan of a potentially long list.

Also, note that this potential long list is an attack vector,
we might consider also using an rb-tree there eventually.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:32 +01:00
Eric Dumazet
29ff723c54 inet: frags: reorganize struct netns_frags
commit c2615cf5a761b32bf74e85bddc223dfff3d9b9f0 upstream.

Put the read-mostly fields in a separate cache line
at the beginning of struct netns_frags, to reduce
false sharing noticed in inet_frag_kill()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:32 +01:00
Eric Dumazet
33990010ea rhashtable: reorganize struct rhashtable layout
commit e5d672a0780d9e7118caad4c171ec88b8299398d upstream.

While under frags DDOS I noticed unfortunate false sharing between
@nelems and @params.automatic_shrinking

Move @nelems at the end of struct rhashtable so that first cache line
is shared between all cpus, because almost never dirtied.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:32 +01:00
Eric Dumazet
bf8187348f ipv6: frags: rewrite ip6_expire_frag_queue()
commit 05c0b86b9696802fd0ce5676a92a63f1b455bdf3 upstream.

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>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:31 +01:00
Eric Dumazet
f925a29652 inet: frags: do not clone skb in ip_expire()
commit 1eec5d5670084ee644597bd26c25e22c69b9f748 upstream.

An skb_clone() was added in commit ec4fbd64751d ("inet: frag: release
spinlock before calling icmp_send()")

While fixing the bug at that time, it also added a very high cost
for DDOS frags, as the ICMP rate limit is applied after this
expensive operation (skb_clone() + consume_skb(), implying memory
allocations, copy, and freeing)

We can use skb_get(head) here, all we want is to make sure skb wont
be freed by another cpu.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:31 +01:00
Eric Dumazet
567ef0554b inet: frags: break the 2GB limit for frags storage
commit 3e67f106f619dcfaf6f4e2039599bdb69848c714 upstream.

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>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:31 +01:00
Eric Dumazet
50fc08963b inet: frags: remove inet_frag_maybe_warn_overflow()
commit 2d44ed22e607f9a285b049de2263e3840673a260 upstream.

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>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:31 +01:00
Eric Dumazet
b047c796de inet: frags: get rif of inet_frag_evicting()
commit 399d1404be660d355192ff4df5ccc3f4159ec1e4 upstream.

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 ec4fbd64751d
("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>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:31 +01:00
Eric Dumazet
cf2b9e68a6 inet: frags: remove some helpers
commit 6befe4a78b1553edb6eed3a78b4bcd9748526672 upstream.

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>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:31 +01:00
Paolo Abeni
f67b17c023 ipfrag: really prevent allocation on netns exit
commit f6f2a4a2eb92bc73671204198bb2f8ab53ff59fb upstream.

Setting the low threshold to 0 has no effect on frags allocation,
we need to clear high_thresh instead.

The code was pre-existent to commit 648700f76b03 ("inet: frags:
use rhashtables for reassembly units"), but before the above,
such assignment had a different role: prevent concurrent eviction
from the worker and the netns cleanup helper.

Fixes: 648700f76b03 ("inet: frags: use rhashtables for reassembly units")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:31 +01:00
Alexander Aring
24641fb645 net: ieee802154: 6lowpan: fix frag reassembly
commit f18fa5de5ba7f1d6650951502bb96a6e4715a948 upstream.

This patch initialize stack variables which are used in
frag_lowpan_compare_key to zero. In my case there are padding bytes in the
structures ieee802154_addr as well in frag_lowpan_compare_key. Otherwise
the key variable contains random bytes. The result is that a compare of
two keys by memcmp works incorrect.

Fixes: 648700f76b03 ("inet: frags: use rhashtables for reassembly units")
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Reported-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:31 +01:00
Eric Dumazet
4931071058 inet: frags: use rhashtables for reassembly units
commit 648700f76b03b7e8149d13cc2bdb3355035258a9 upstream.

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>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:31 +01:00
Eric Dumazet
bf5ea30ff5 rhashtable: add schedule points
commit ae6da1f503abb5a5081f9f6c4a6881de97830f3e upstream.

Rehashing and destroying large hash table takes a lot of time,
and happens in process context. It is safe to add cond_resched()
in rhashtable_rehash_table() and rhashtable_free_and_destroy()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:31 +01:00
Ben Hutchings
9e5f4d0b79 rhashtable: Add rhashtable_lookup()
Extracted from commit ca26893f05e8 "rhashtable: Add rhlist interface".

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:30 +01:00
Pablo Neira Ayuso
8295999786 rhashtable: add rhashtable_lookup_get_insert_key()
commit 5ca8cc5bf11faed257c762018aea9106d529232f upstream.

This patch modifies __rhashtable_insert_fast() so it returns the
existing object that clashes with the one that you want to insert.
In case the object is successfully inserted, NULL is returned.
Otherwise, you get an error via ERR_PTR().

This patch adapts the existing callers of __rhashtable_insert_fast()
so they handle this new logic, and it adds a new
rhashtable_lookup_get_insert_key() interface to fetch this existing
object.

nf_tables needs this change to improve handling of EEXIST cases via
honoring the NLM_F_EXCL flag and by checking if the data part of the
mapping matches what we have.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:30 +01:00
Eric Dumazet
a7fb573c16 inet: frags: refactor lowpan_net_frag_init()
commit 807f1844df4ac23594268fa9f41902d0549e92aa upstream.

We want to call lowpan_net_frag_init() earlier.
Similar to commit "inet: frags: refactor ipv6_frag_init()"

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>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:30 +01:00
Eric Dumazet
705e71ed99 inet: frags: refactor ipv6_frag_init()
commit 5b975bab23615cd0fdf67af6c9298eb01c4b9f61 upstream.

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>
[bwh: Backported to 4.4: Also delete a redundant assignment to
 ip6_frags.skb_free]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:30 +01:00
Eric Dumazet
8c639cad89 inet: frags: refactor ipfrag_init()
commit 483a6e4fa055123142d8956866fe2aa9c98d546d upstream.

We need to call inet_frags_init() before register_pernet_subsys(),
as a prereq for following patch ("inet: frags: use rhashtables for reassembly units")

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:30 +01:00
Eric Dumazet
9c6727de82 inet: frags: add a pointer to struct netns_frags
commit 093ba72914b696521e4885756a68a3332782c8de upstream.

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>
[bwh: Backported to 4.4: inet_frag_{kill,put}() are called in some
 different places; update all calls]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:30 +01:00
Eric Dumazet
5eb2471ef4 inet: frags: change inet_frags_init_net() return value
commit 787bea7748a76130566f881c2342a0be4127d182 upstream.

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>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08 11:25:30 +01:00
Greg Kroah-Hartman
64b564428f This is the 4.4.173 stable release
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Merge 4.4.173 into android-4.4

Changes in 4.4.173
	net: Fix usage of pskb_trim_rcsum
	openvswitch: Avoid OOB read when parsing flow nlattrs
	net: ipv4: Fix memory leak in network namespace dismantle
	net_sched: refetch skb protocol for each filter
	net: bridge: Fix ethernet header pointer before check skb forwardable
	USB: serial: simple: add Motorola Tetra TPG2200 device id
	USB: serial: pl2303: add new PID to support PL2303TB
	ASoC: atom: fix a missing check of snd_pcm_lib_malloc_pages
	ARC: perf: map generic branches to correct hardware condition
	s390/early: improve machine detection
	s390/smp: fix CPU hotplug deadlock with CPU rescan
	char/mwave: fix potential Spectre v1 vulnerability
	staging: rtl8188eu: Add device code for D-Link DWA-121 rev B1
	tty: Handle problem if line discipline does not have receive_buf
	tty/n_hdlc: fix __might_sleep warning
	CIFS: Fix possible hang during async MTU reads and writes
	Input: xpad - add support for SteelSeries Stratus Duo
	KVM: x86: Fix single-step debugging
	x86/kaslr: Fix incorrect i8254 outb() parameters
	can: dev: __can_get_echo_skb(): fix bogous check for non-existing skb by removing it
	can: bcm: check timer values before ktime conversion
	vt: invoke notifier on screen size change
	perf unwind: Unwind with libdw doesn't take symfs into account
	perf unwind: Take pgoff into account when reporting elf to libdwfl
	irqchip/gic-v3-its: Align PCI Multi-MSI allocation on their size
	arm64: mm: remove page_mapping check in __sync_icache_dcache
	f2fs: read page index before freeing
	Revert "loop: Fix double mutex_unlock(&loop_ctl_mutex) in loop_control_ioctl()"
	Revert "loop: Get rid of loop_index_mutex"
	Revert "loop: Fold __loop_release into loop_release"
	s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU
	fs: add the fsnotify call to vfs_iter_write
	ipv6: Consider sk_bound_dev_if when binding a socket to an address
	l2tp: copy 4 more bytes to linear part if necessary
	net/mlx4_core: Add masking for a few queries on HCA caps
	netrom: switch to sock timer API
	net/rose: fix NULL ax25_cb kernel panic
	ucc_geth: Reset BQL queue when stopping device
	l2tp: remove l2specific_len dependency in l2tp_core
	l2tp: fix reading optional fields of L2TPv3
	CIFS: Do not count -ENODATA as failure for query directory
	fs/dcache: Fix incorrect nr_dentry_unused accounting in shrink_dcache_sb()
	ARM: cns3xxx: Fix writing to wrong PCI config registers after alignment
	arm64: hyp-stub: Forbid kprobing of the hyp-stub
	gfs2: Revert "Fix loop in gfs2_rbm_find"
	platform/x86: asus-nb-wmi: Map 0x35 to KEY_SCREENLOCK
	platform/x86: asus-nb-wmi: Drop mapping of 0x33 and 0x34 scan codes
	mmc: sdhci-iproc: handle mmc_of_parse() errors during probe
	kernel/exit.c: release ptraced tasks before zap_pid_ns_processes
	mm, oom: fix use-after-free in oom_kill_process
	cifs: Always resolve hostname before reconnecting
	drivers: core: Remove glue dirs from sysfs earlier
	mm: migrate: don't rely on __PageMovable() of newpage after unlocking it
	fs: don't scan the inode cache before SB_BORN is set
	Linux 4.4.173

Change-Id: Ifc01c8b56016e9145bb67258f91dfc6b6983354c
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-02-07 09:24:50 +01:00
Greg Kroah-Hartman
343f981c76 Linux 4.4.173 2019-02-06 19:43:08 +01:00
Dave Chinner
16925957b8 fs: don't scan the inode cache before SB_BORN is set
commit 79f546a696bff2590169fb5684e23d65f4d9f591 upstream.

We recently had an oops reported on a 4.14 kernel in
xfs_reclaim_inodes_count() where sb->s_fs_info pointed to garbage
and so the m_perag_tree lookup walked into lala land.  It produces
an oops down this path during the failed mount:

  radix_tree_gang_lookup_tag+0xc4/0x130
  xfs_perag_get_tag+0x37/0xf0
  xfs_reclaim_inodes_count+0x32/0x40
  xfs_fs_nr_cached_objects+0x11/0x20
  super_cache_count+0x35/0xc0
  shrink_slab.part.66+0xb1/0x370
  shrink_node+0x7e/0x1a0
  try_to_free_pages+0x199/0x470
  __alloc_pages_slowpath+0x3a1/0xd20
  __alloc_pages_nodemask+0x1c3/0x200
  cache_grow_begin+0x20b/0x2e0
  fallback_alloc+0x160/0x200
  kmem_cache_alloc+0x111/0x4e0

The problem is that the superblock shrinker is running before the
filesystem structures it depends on have been fully set up. i.e.
the shrinker is registered in sget(), before ->fill_super() has been
called, and the shrinker can call into the filesystem before
fill_super() does it's setup work. Essentially we are exposed to
both use-after-free and use-before-initialisation bugs here.

To fix this, add a check for the SB_BORN flag in super_cache_count.
In general, this flag is not set until ->fs_mount() completes
successfully, so we know that it is set after the filesystem
setup has completed. This matches the trylock_super() behaviour
which will not let super_cache_scan() run if SB_BORN is not set, and
hence will not allow the superblock shrinker from entering the
filesystem while it is being set up or after it has failed setup
and is being torn down.

Cc: stable@kernel.org
Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Aaron Lu <aaron.lu@linux.alibaba.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 19:43:08 +01:00
David Hildenbrand
57d8138631 mm: migrate: don't rely on __PageMovable() of newpage after unlocking it
commit e0a352fabce61f730341d119fbedf71ffdb8663f upstream.

We had a race in the old balloon compaction code before b1123ea6d3b3
("mm: balloon: use general non-lru movable page feature") refactored it
that became visible after backporting 195a8c43e93d ("virtio-balloon:
deflate via a page list") without the refactoring.

The bug existed from commit d6d86c0a7f ("mm/balloon_compaction:
redesign ballooned pages management") till b1123ea6d3b3 ("mm: balloon:
use general non-lru movable page feature").  d6d86c0a7f
("mm/balloon_compaction: redesign ballooned pages management") was
backported to 3.12, so the broken kernels are stable kernels [3.12 -
4.7].

There was a subtle race between dropping the page lock of the newpage in
__unmap_and_move() and checking for __is_movable_balloon_page(newpage).

Just after dropping this page lock, virtio-balloon could go ahead and
deflate the newpage, effectively dequeueing it and clearing PageBalloon,
in turn making __is_movable_balloon_page(newpage) fail.

This resulted in dropping the reference of the newpage via
putback_lru_page(newpage) instead of put_page(newpage), leading to
page->lru getting modified and a !LRU page ending up in the LRU lists.
With 195a8c43e93d ("virtio-balloon: deflate via a page list")
backported, one would suddenly get corrupted lists in
release_pages_balloon():

- WARNING: CPU: 13 PID: 6586 at lib/list_debug.c:59 __list_del_entry+0xa1/0xd0
- list_del corruption. prev->next should be ffffe253961090a0, but was dead000000000100

Nowadays this race is no longer possible, but it is hidden behind very
ugly handling of __ClearPageMovable() and __PageMovable().

__ClearPageMovable() will not make __PageMovable() fail, only
PageMovable().  So the new check (__PageMovable(newpage)) will still
hold even after newpage was dequeued by virtio-balloon.

If anybody would ever change that special handling, the BUG would be
introduced again.  So instead, make it explicit and use the information
of the original isolated page before migration.

This patch can be backported fairly easy to stable kernels (in contrast
to the refactoring).

Link: http://lkml.kernel.org/r/20190129233217.10747-1-david@redhat.com
Fixes: d6d86c0a7f ("mm/balloon_compaction: redesign ballooned pages management")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Vratislav Bendel <vbendel@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vratislav Bendel <vbendel@redhat.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>	[3.12 - 4.7]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 19:43:08 +01:00
Benjamin Herrenschmidt
a51bbfef6d drivers: core: Remove glue dirs from sysfs earlier
commit 726e41097920a73e4c7c33385dcc0debb1281e18 upstream.

For devices with a class, we create a "glue" directory between
the parent device and the new device with the class name.

This directory is never "explicitely" removed when empty however,
this is left to the implicit sysfs removal done by kobject_release()
when the object loses its last reference via kobject_put().

This is problematic because as long as it's not been removed from
sysfs, it is still present in the class kset and in sysfs directory
structure.

The presence in the class kset exposes a use after free bug fixed
by the previous patch, but the presence in sysfs means that until
the kobject is released, which can take a while (especially with
kobject debugging), any attempt at re-creating such as binding a
new device for that class/parent pair, will result in a sysfs
duplicate file name error.

This fixes it by instead doing an explicit kobject_del() when
the glue dir is empty, by keeping track of the number of
child devices of the gluedir.

This is made easy by the fact that all glue dir operations are
done with a global mutex, and there's already a function
(cleanup_glue_dir) called in all the right places taking that
mutex that can be enhanced for this. It appears that this was
in fact the intent of the function, but the implementation was
wrong.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Zubin Mithra <zsm@chromium.org>
Cc: Guenter Roeck <groeck@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 19:43:08 +01:00
Paulo Alcantara
8f51e79cee cifs: Always resolve hostname before reconnecting
commit 28eb24ff75c5ac130eb326b3b4d0dcecfc0f427d upstream.

In case a hostname resolves to a different IP address (e.g. long
running mounts), make sure to resolve it every time prior to calling
generic_ip_connect() in reconnect.

Suggested-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 19:43:07 +01:00
Shakeel Butt
c3ef8a44e7 mm, oom: fix use-after-free in oom_kill_process
commit cefc7ef3c87d02fc9307835868ff721ea12cc597 upstream.

Syzbot instance running on upstream kernel found a use-after-free bug in
oom_kill_process.  On further inspection it seems like the process
selected to be oom-killed has exited even before reaching
read_lock(&tasklist_lock) in oom_kill_process().  More specifically the
tsk->usage is 1 which is due to get_task_struct() in oom_evaluate_task()
and the put_task_struct within for_each_thread() frees the tsk and
for_each_thread() tries to access the tsk.  The easiest fix is to do
get/put across the for_each_thread() on the selected task.

Now the next question is should we continue with the oom-kill as the
previously selected task has exited? However before adding more
complexity and heuristics, let's answer why we even look at the children
of oom-kill selected task? The select_bad_process() has already selected
the worst process in the system/memcg.  Due to race, the selected
process might not be the worst at the kill time but does that matter?
The userspace can use the oom_score_adj interface to prefer children to
be killed before the parent.  I looked at the history but it seems like
this is there before git history.

Link: http://lkml.kernel.org/r/20190121215850.221745-1-shakeelb@google.com
Reported-by: syzbot+7fbbfa368521945f0e3d@syzkaller.appspotmail.com
Fixes: 6b0c81b3be ("mm, oom: reduce dependency on tasklist_lock")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 19:43:07 +01:00
Andrei Vagin
e790eeabc4 kernel/exit.c: release ptraced tasks before zap_pid_ns_processes
commit 8fb335e078378c8426fabeed1ebee1fbf915690c upstream.

Currently, exit_ptrace() adds all ptraced tasks in a dead list, then
zap_pid_ns_processes() waits on all tasks in a current pidns, and only
then are tasks from the dead list released.

zap_pid_ns_processes() can get stuck on waiting tasks from the dead
list.  In this case, we will have one unkillable process with one or
more dead children.

Thanks to Oleg for the advice to release tasks in find_child_reaper().

Link: http://lkml.kernel.org/r/20190110175200.12442-1-avagin@gmail.com
Fixes: 7c8bd2322c ("exit: ptrace: shift "reap dead" code from exit_ptrace() to forget_original_parent()")
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 19:43:07 +01:00
Stefan Wahren
3027ecc100 mmc: sdhci-iproc: handle mmc_of_parse() errors during probe
commit 2bd44dadd5bfb4135162322fd0b45a174d4ad5bf upstream.

We need to handle mmc_of_parse() errors during probe.

This finally fixes the wifi regression on Raspberry Pi 3 series.
In error case the wifi chip was permanently in reset because of
the power sequence depending on the deferred probe of the GPIO expander.

Fixes: b580c52d58 ("mmc: sdhci-iproc: add IPROC SDHCI driver")
Cc: stable@vger.kernel.org
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 19:43:07 +01:00
João Paulo Rechi Vita
86a395c27a platform/x86: asus-nb-wmi: Drop mapping of 0x33 and 0x34 scan codes
[ Upstream commit 71b12beaf12f21a53bfe100795d0797f1035b570 ]

According to Asus firmware engineers, the meaning of these codes is only
to notify the OS that the screen brightness has been turned on/off by
the EC. This does not match the meaning of KEY_DISPLAYTOGGLE /
KEY_DISPLAY_OFF, where userspace is expected to change the display
brightness.

Signed-off-by: João Paulo Rechi Vita <jprvita@endlessm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-06 19:43:07 +01:00
João Paulo Rechi Vita
5d0868d872 platform/x86: asus-nb-wmi: Map 0x35 to KEY_SCREENLOCK
[ Upstream commit b3f2f3799a972d3863d0fdc2ab6287aef6ca631f ]

When the OS registers to handle events from the display off hotkey the
EC will send a notification with 0x35 for every key press, independent
of the backlight state.

The behavior of this key on Windows, with the ATKACPI driver from Asus
installed, is turning off the backlight of all connected displays with a
fading effect, and any cursor input or key press turning the backlight
back on. The key press or cursor input that wakes up the display is also
passed through to the application under the cursor or under focus.

The key that matches this behavior the closest is KEY_SCREENLOCK.

Signed-off-by: João Paulo Rechi Vita <jprvita@endlessm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-06 19:43:07 +01:00
Andreas Gruenbacher
970e5c267c gfs2: Revert "Fix loop in gfs2_rbm_find"
commit e74c98ca2d6ae4376cc15fa2a22483430909d96b upstream.

This reverts commit 2d29f6b96d8f80322ed2dd895bca590491c38d34.

It turns out that the fix can lead to a ~20 percent performance regression
in initial writes to the page cache according to iozone.  Let's revert this
for now to have more time for a proper fix.

Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 19:43:07 +01:00
James Morse
7685bb0efb arm64: hyp-stub: Forbid kprobing of the hyp-stub
commit 8fac5cbdfe0f01254d9d265c6aa1a95f94f58595 upstream.

The hyp-stub is loaded by the kernel's early startup code at EL2
during boot, before KVM takes ownership later. The hyp-stub's
text is part of the regular kernel text, meaning it can be kprobed.

A breakpoint in the hyp-stub causes the CPU to spin in el2_sync_invalid.

Add it to the __hyp_text.

Signed-off-by: James Morse <james.morse@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 19:43:07 +01:00
Koen Vandeputte
1472585f51 ARM: cns3xxx: Fix writing to wrong PCI config registers after alignment
commit 65dbb423cf28232fed1732b779249d6164c5999b upstream.

Originally, cns3xxx used its own functions for mapping, reading and
writing config registers.

Commit 802b7c06ad ("ARM: cns3xxx: Convert PCI to use generic config
accessors") removed the internal PCI config write function in favor of
the generic one:

  cns3xxx_pci_write_config() --> pci_generic_config_write()

cns3xxx_pci_write_config() expected aligned addresses, being produced by
cns3xxx_pci_map_bus() while the generic one pci_generic_config_write()
actually expects the real address as both the function and hardware are
capable of byte-aligned writes.

This currently leads to pci_generic_config_write() writing to the wrong
registers.

For instance, upon ath9k module loading:

- driver ath9k gets loaded
- The driver wants to write value 0xA8 to register PCI_LATENCY_TIMER,
  located at 0x0D
- cns3xxx_pci_map_bus() aligns the address to 0x0C
- pci_generic_config_write() effectively writes 0xA8 into register 0x0C
  (CACHE_LINE_SIZE)

Fix the bug by removing the alignment in the cns3xxx mapping function.

Fixes: 802b7c06ad ("ARM: cns3xxx: Convert PCI to use generic config accessors")
Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Krzysztof Halasa <khalasa@piap.pl>
Acked-by: Tim Harvey <tharvey@gateworks.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
CC: stable@vger.kernel.org	# v4.0+
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: Olof Johansson <olof@lixom.net>
CC: Robin Leblon <robin.leblon@ncentric.com>
CC: Rob Herring <robh@kernel.org>
CC: Russell King <linux@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 19:43:07 +01:00