linux-stable.git, branch v3.18.99

Linux 3.18.99

2018-03-11T15:12:20+00:00

dm io: fix duplicate bio completion due to missing ref count

2018-03-11T15:12:19+00:00

commit feb7695fe9fb83084aa29de0094774f4c9d4c9fc upstream.

If only a subset of the devices associated with multiple regions support
a given special operation (eg. DISCARD) then the dec_count() that is
used to set error for the region must increment the io->count.

Otherwise, when the dec_count() is called it can cause the dm-io
caller's bio to be completed multiple times.  As was reported against
the dm-mirror target that had mirror legs with a mix of discard
capabilities.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=196077
Reported-by: Zhang Yi 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

fib_semantics: Don't match route with mismatching tclassid

2018-03-11T15:12:19+00:00

[ Upstream commit a8c6db1dfd1b1d18359241372bb204054f2c3174 ]

In fib_nh_match(), if output interface or gateway are passed in
the FIB configuration, we don't have to check next hops of
multipath routes to conclude whether we have a match or not.

However, we might still have routes with different realms
matching the same output interface and gateway configuration,
and this needs to cause the match to fail. Otherwise the first
route inserted in the FIB will match, regardless of the realms:

 # ip route add 1.1.1.1 dev eth0 table 1234 realms 1/2
 # ip route append 1.1.1.1 dev eth0 table 1234 realms 3/4
 # ip route list table 1234
 1.1.1.1 dev eth0 scope link realms 1/2
 1.1.1.1 dev eth0 scope link realms 3/4
 # ip route del 1.1.1.1 dev ens3 table 1234 realms 3/4
 # ip route list table 1234
 1.1.1.1 dev ens3 scope link realms 3/4

whereas route with realms 3/4 should have been deleted instead.

Explicitly check for fc_flow passed in the FIB configuration
(this comes from RTA_FLOW extracted by rtm_to_fib_config()) and
fail matching if it differs from nh_tclassid.

The handling of RTA_FLOW for multipath routes later in
fib_nh_match() is still needed, as we can have multiple RTA_FLOW
attributes that need to be matched against the tclassid of each
next hop.

v2: Check that fc_flow is set before discarding the match, so
    that the user can still select the first matching rule by
    not specifying any realm, as suggested by David Ahern.

Reported-by: Jianlin Shi 
Signed-off-by: Stefano Brivio 
Acked-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipv4: don't allow setting net.ipv4.route.min_pmtu below 68

2018-03-11T15:12:19+00:00

[ Upstream commit c7272c2f1229125f74f22dcdd59de9bbd804f1c8 ]

According to RFC 1191 sections 3 and 4, ICMP frag-needed messages
indicating an MTU below 68 should be rejected:

    A host MUST never reduce its estimate of the Path MTU below 68
    octets.

and (talking about ICMP frag-needed's Next-Hop MTU field):

    This field will never contain a value less than 68, since every
    router "must be able to forward a datagram of 68 octets without
    fragmentation".

Furthermore, by letting net.ipv4.route.min_pmtu be set to negative
values, we can end up with a very large PMTU when (-1) is cast into u32.

Let's also make ip_rt_min_pmtu a u32, since it's only ever compared to
unsigned ints.

Reported-by: Jianlin Shi 
Signed-off-by: Sabrina Dubroca 
Reviewed-by: Stefano Brivio 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sctp: verify size of a new chunk in _sctp_make_chunk()

2018-03-11T15:12:19+00:00

[ Upstream commit 07f2c7ab6f8d0a7e7c5764c4e6cc9c52951b9d9c ]

When SCTP makes INIT or INIT_ACK packet the total chunk length
can exceed SCTP_MAX_CHUNK_LEN which leads to kernel panic when
transmitting these packets, e.g. the crash on sending INIT_ACK:

[  597.804948] skbuff: skb_over_panic: text:00000000ffae06e4 len:120168
               put:120156 head:000000007aa47635 data:00000000d991c2de
               tail:0x1d640 end:0xfec0 dev:
...
[  597.976970] ------------[ cut here ]------------
[  598.033408] kernel BUG at net/core/skbuff.c:104!
[  600.314841] Call Trace:
[  600.345829]  
[  600.371639]  ? sctp_packet_transmit+0x2095/0x26d0 [sctp]
[  600.436934]  skb_put+0x16c/0x200
[  600.477295]  sctp_packet_transmit+0x2095/0x26d0 [sctp]
[  600.540630]  ? sctp_packet_config+0x890/0x890 [sctp]
[  600.601781]  ? __sctp_packet_append_chunk+0x3b4/0xd00 [sctp]
[  600.671356]  ? sctp_cmp_addr_exact+0x3f/0x90 [sctp]
[  600.731482]  sctp_outq_flush+0x663/0x30d0 [sctp]
[  600.788565]  ? sctp_make_init+0xbf0/0xbf0 [sctp]
[  600.845555]  ? sctp_check_transmitted+0x18f0/0x18f0 [sctp]
[  600.912945]  ? sctp_outq_tail+0x631/0x9d0 [sctp]
[  600.969936]  sctp_cmd_interpreter.isra.22+0x3be1/0x5cb0 [sctp]
[  601.041593]  ? sctp_sf_do_5_1B_init+0x85f/0xc30 [sctp]
[  601.104837]  ? sctp_generate_t1_cookie_event+0x20/0x20 [sctp]
[  601.175436]  ? sctp_eat_data+0x1710/0x1710 [sctp]
[  601.233575]  sctp_do_sm+0x182/0x560 [sctp]
[  601.284328]  ? sctp_has_association+0x70/0x70 [sctp]
[  601.345586]  ? sctp_rcv+0xef4/0x32f0 [sctp]
[  601.397478]  ? sctp6_rcv+0xa/0x20 [sctp]
...

Here the chunk size for INIT_ACK packet becomes too big, mostly
because of the state cookie (INIT packet has large size with
many address parameters), plus additional server parameters.

Later this chunk causes the panic in skb_put_data():

  skb_packet_transmit()
      sctp_packet_pack()
          skb_put_data(nskb, chunk->skb->data, chunk->skb->len);

'nskb' (head skb) was previously allocated with packet->size
from u16 'chunk->chunk_hdr->length'.

As suggested by Marcelo we should check the chunk's length in
_sctp_make_chunk() before trying to allocate skb for it and
discard a chunk if its size bigger than SCTP_MAX_CHUNK_LEN.

Signed-off-by: Alexey Kodanev 
Acked-by: Marcelo Ricardo Leitner 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

s390/qeth: fix IPA command submission race

2018-03-11T15:12:19+00:00

[ Upstream commit d22ffb5a712f9211ffd104c38fc17cbfb1b5e2b0 ]

If multiple IPA commands are build & sent out concurrently,
fill_ipacmd_header() may assign a seqno value to a command that's
different from what send_control_data() later assigns to this command's
reply.
This is due to other commands passing through send_control_data(),
and incrementing card->seqno.ipa along the way.

So one IPA command has no reply that's waiting for its seqno, while some
other IPA command has multiple reply objects waiting for it.
Only one of those waiting replies wins, and the other(s) times out and
triggers a recovery via send_ipa_cmd().

Fix this by making sure that the same seqno value is assigned to
a command and its reply object.
Do so immediately before submitting the command & while holding the
irq_pending "lock", to produce nicely ascending seqnos.

As a side effect, *all* IPA commands now use a reply object that's
waiting for its actual seqno. Previously, early IPA commands that were
submitted while the card was still DOWN used the "catch-all" IDX seqno.

Signed-off-by: Julian Wiedmann 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

s390/qeth: fix SETIP command handling

2018-03-11T15:12:19+00:00

[ Upstream commit 1c5b2216fbb973a9410e0b06389740b5c1289171 ]

send_control_data() applies some special handling to SETIP v4 IPA
commands. But current code parses *all* command types for the SETIP
command code. Limit the command code check to IPA commands.

Fixes: 5b54e16f1a54 ("qeth: do not spin for SETIP ip assist command")
Signed-off-by: Julian Wiedmann 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sctp: fix dst refcnt leak in sctp_v6_get_dst()

2018-03-11T15:12:19+00:00

[ Upstream commit 957d761cf91cdbb175ad7d8f5472336a4d54dbf2 ]

When going through the bind address list in sctp_v6_get_dst() and
the previously found address is better ('matchlen > bmatchlen'),
the code continues to the next iteration without releasing currently
held destination.

Fix it by releasing 'bdst' before continue to the next iteration, and
instead of introducing one more '!IS_ERR(bdst)' check for dst_release(),
move the already existed one right after ip6_dst_lookup_flow(), i.e. we
shouldn't proceed further if we get an error for the route lookup.

Fixes: dbc2b5e9a09e ("sctp: fix src address selection if using secondary addresses for ipv6")
Signed-off-by: Alexey Kodanev 
Acked-by: Neil Horman 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

udplite: fix partial checksum initialization

2018-03-11T15:12:19+00:00

[ Upstream commit 15f35d49c93f4fa9875235e7bf3e3783d2dd7a1b ]

Since UDP-Lite is always using checksum, the following path is
triggered when calculating pseudo header for it:

  udp4_csum_init() or udp6_csum_init()
    skb_checksum_init_zero_check()
      __skb_checksum_validate_complete()

The problem can appear if skb->len is less than CHECKSUM_BREAK. In
this particular case __skb_checksum_validate_complete() also invokes
__skb_checksum_complete(skb). If UDP-Lite is using partial checksum
that covers only part of a packet, the function will return bad
checksum and the packet will be dropped.

It can be fixed if we skip skb_checksum_init_zero_check() and only
set the required pseudo header checksum for UDP-Lite with partial
checksum before udp4_csum_init()/udp6_csum_init() functions return.

Fixes: ed70fcfcee95 ("net: Call skb_checksum_init in IPv4")
Fixes: e4f45b7f40bd ("net: Call skb_checksum_init in IPv6")
Signed-off-by: Alexey Kodanev 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ppp: prevent unregistered channels from connecting to PPP units

2018-03-11T15:12:19+00:00

[ Upstream commit 77f840e3e5f09c6d7d727e85e6e08276dd813d11 ]

PPP units don't hold any reference on the channels connected to it.
It is the channel's responsibility to ensure that it disconnects from
its unit before being destroyed.
In practice, this is ensured by ppp_unregister_channel() disconnecting
the channel from the unit before dropping a reference on the channel.

However, it is possible for an unregistered channel to connect to a PPP
unit: register a channel with ppp_register_net_channel(), attach a
/dev/ppp file to it with ioctl(PPPIOCATTCHAN), unregister the channel
with ppp_unregister_channel() and finally connect the /dev/ppp file to
a PPP unit with ioctl(PPPIOCCONNECT).

Once in this situation, the channel is only held by the /dev/ppp file,
which can be released at anytime and free the channel without letting
the parent PPP unit know. Then the ppp structure ends up with dangling
pointers in its ->channels list.

Prevent this scenario by forbidding unregistered channels from
connecting to PPP units. This maintains the code logic by keeping
ppp_unregister_channel() responsible from disconnecting the channel if
necessary and avoids modification on the reference counting mechanism.

This issue seems to predate git history (successfully reproduced on
Linux 2.6.26 and earlier PPP commits are unrelated).

Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman