19 May, 2018
1 commit
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[ Upstream commit 59d8d4434f429b4fa8a346fd889058bda427a837 ]
Now sctp only delays the authentication for the normal cookie-echo
chunk by setting chunk->auth_chunk in sctp_endpoint_bh_rcv(). But
for the duplicated one with auth, in sctp_assoc_bh_rcv(), it does
authentication first based on the old asoc, which will definitely
fail due to the different auth info in the old asoc.The duplicated cookie-echo chunk will create a new asoc with the
auth info from this chunk, and the authentication should also be
done with the new asoc's auth info for all of the collision 'A',
'B' and 'D'. Otherwise, the duplicated cookie-echo chunk with auth
will never pass the authentication and create the new connection.This issue exists since very beginning, and this fix is to make
sctp_assoc_bh_rcv() follow the way sctp_endpoint_bh_rcv() does
for the normal cookie-echo chunk to delay the authentication.While at it, remove the unused params from sctp_sf_authenticate()
and define sctp_auth_chunk_verify() used for all the places that
do the delayed authentication.v1->v2:
fix the typo in changelog as Marcelo noticed.Acked-by: Marcelo Ricardo Leitner
Signed-off-by: Xin Long
Acked-by: Neil Horman
Signed-off-by: David S. Miller
Signed-off-by: Greg Kroah-Hartman
07 Aug, 2017
3 commits
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This patch is to remove the typedef sctp_subtype_t, and
replace with union sctp_subtype in the places where it's
using this typedef.Note that it doesn't fix many indents although it should,
as sctp_disposition_t's removal would mess them up again.
So better to fix them when removing sctp_disposition_t in
later patch.Signed-off-by: Xin Long
Signed-off-by: David S. Miller -
This patch is to remove the typedef sctp_transport_cmd_t, and
replace with enum sctp_transport_cmd in the places where it's
using this typedef.Signed-off-by: Xin Long
Signed-off-by: David S. Miller -
This patch is to remove the typedef sctp_scope_t, and
replace with enum sctp_scope in the places where it's
using this typedef.Signed-off-by: Xin Long
Signed-off-by: David S. Miller
05 Jul, 2017
1 commit
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refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.Signed-off-by: Elena Reshetova
Signed-off-by: Hans Liljestrand
Signed-off-by: Kees Cook
Signed-off-by: David Windsor
Signed-off-by: David S. Miller
02 Jul, 2017
1 commit
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This patch is to remove the typedef sctp_paramhdr_t, and replace
with struct sctp_paramhdr in the places where it's using this
typedef.It is also to fix some indents and use sizeof(variable) instead
of sizeof(type).Signed-off-by: Xin Long
Signed-off-by: David S. Miller
21 Jun, 2017
1 commit
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It's a bad thing not to handle errors when updating asoc. The memory
allocation failure in any of the functions called in sctp_assoc_update()
would cause sctp to work unexpectedly.This patch is to fix it by aborting the asoc and reporting the error when
any of these functions fails.Signed-off-by: Xin Long
Acked-by: Neil Horman
Acked-by: Marcelo Ricardo Leitner
Signed-off-by: David S. Miller
11 Jun, 2017
1 commit
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sctp_assoc_set_id does the assoc id check in the beginning when
processing dupcookie, no need to do the same check before calling
it.v1->v2:
fix some typo errs Marcelo pointed in changelog.Signed-off-by: Xin Long
Acked-by: Marcelo Ricardo Leitner
Signed-off-by: David S. Miller
03 Jun, 2017
2 commits
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Since last patch, sctp doesn't need to alloc memory for asoc->stream any
more. sctp_stream_new and sctp_stream_init both are used to alloc memory
for stream.in or stream.out, and their names are also confusing.This patch is to merge them into sctp_stream_init, and only pass stream
and streamcnt parameters into it, instead of the whole asoc.Signed-off-by: Xin Long
Signed-off-by: David S. Miller -
As Marcelo's suggestion, stream is a fixed size member of asoc and would
not grow with more streams. To avoid an allocation for it, this patch is
to define it as an object instead of pointer and update the places using
it, also create sctp_stream_update() called in sctp_assoc_update() to
migrate the stream info from one stream to another.Signed-off-by: Xin Long
Signed-off-by: David S. Miller
25 May, 2017
1 commit
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Since commit 3dbcc105d556 ("sctp: alloc stream info when initializing
asoc"), stream and stream.out info are always alloced when creating
an asoc.So it's not correct to check !asoc->stream before updating stream
info when processing dupcookie, but would be better to check asoc
state instead.Fixes: 3dbcc105d556 ("sctp: alloc stream info when initializing asoc")
Signed-off-by: Xin Long
Acked-by: Neil Horman
Acked-by: Vlad Yasevich
Signed-off-by: David S. Miller
05 Apr, 2017
1 commit
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This patch is almost to revert commit 02f3d4ce9e81 ("sctp: Adjust PMTU
updates to accomodate route invalidation."). As t->asoc can't be NULL
in sctp_transport_update_pmtu, it could get sk from asoc, and no need
to pass sk into that function.It is also to remove some duplicated codes from that function.
Signed-off-by: Xin Long
Acked-by: Marcelo Ricardo Leitner
Signed-off-by: David S. Miller
31 Mar, 2017
1 commit
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When sending a msg without asoc established, sctp will send INIT packet
first and then enqueue chunks.Before receiving INIT_ACK, stream info is not yet alloced. But enqueuing
chunks needs to access stream info, like out stream state and out stream
cnt.This patch is to fix it by allocing out stream info when initializing an
asoc, allocing in stream and re-allocing out stream when processing init.Signed-off-by: Xin Long
Signed-off-by: David S. Miller
23 Mar, 2017
1 commit
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This patch is to remove the unnecessary temporary variable 'err' from
sctp_association_init.Signed-off-by: Xin Long
Acked-by: Neil Horman
Signed-off-by: David S. Miller
08 Feb, 2017
1 commit
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Add new transport flag to allow sockets to confirm neighbour.
When same struct dst_entry can be used for many different
neighbours we can not use it for pending confirmations.
The flag is propagated from transport to every packet.
It is reset when cached dst is reset.Reported-by: YueHaibing
Fixes: 5110effee8fd ("net: Do delayed neigh confirmation.")
Fixes: f2bb4bedf35d ("ipv4: Cache output routes in fib_info nexthops.")
Signed-off-by: Julian Anastasov
Acked-by: Eric Dumazet
Acked-by: Neil Horman
Signed-off-by: David S. Miller
19 Jan, 2017
4 commits
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This patch is to add sockopt SCTP_ENABLE_STREAM_RESET to get/set
strreset_enable to indicate which reconf request type it supports,
which is described in rfc6525 section 6.3.1.Signed-off-by: Xin Long
Signed-off-by: David S. Miller -
This patch is to add reconf_enable field in all of asoc ep and netns
to indicate if they support stream reset.When initializing, asoc reconf_enable get the default value from ep
reconf_enable which is from netns netns reconf_enable by default.It is also to add reconf_capable in asoc peer part to know if peer
supports reconf_enable, the value is set if ext params have reconf
chunk support when processing init chunk, just as rfc6525 section
5.1.1 demands.Signed-off-by: Xin Long
Signed-off-by: David S. Miller -
This patch is to add a per transport timer based on sctp timer frame
for stream reconf chunk retransmission. It would start after sending
a reconf request chunk, and stop after receiving the response chunk.If the timer expires, besides retransmitting the reconf request chunk,
it would also do the same thing with data RTO timer. like to increase
the appropriate error counts, and perform threshold management, possibly
destroying the asoc if sctp retransmission thresholds are exceeded, just
as section 5.1.1 describes.This patch is also to add asoc strreset_chunk, it is used to save the
reconf request chunk, so that it can be retransmitted, and to check if
the response is really for this request by comparing the information
inside with the response chunk as well.Signed-off-by: Xin Long
Signed-off-by: David S. Miller -
This patch is to add asoc strreset_outseq and strreset_inseq for
saving the reconf request sequence, initialize them when create
assoc and process init, and also to define Incoming and Outgoing
SSN Reset Request Parameter described in rfc6525 section 4.1 and
4.2, As they can be in one same chunk as section rfc6525 3.1-3
describes, it makes them in one function.Signed-off-by: Xin Long
Signed-off-by: David S. Miller
07 Jan, 2017
1 commit
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sctp stream reconf, described in RFC 6525, needs a structure to
save per stream information in assoc, like stream state.In the future, sctp stream scheduler also needs it to save some
stream scheduler params and queues.This patchset is to prepare the stream array in assoc for stream
reconf. It defines sctp_stream that includes stream arrays inside
to replace ssnmap.Note that we use different structures for IN and OUT streams, as
the members in per OUT stream will get more and more different
from per IN stream.v1->v2:
- put these patches into a smaller group.
v2->v3:
- define sctp_stream to contain stream arrays, and create stream.c
to put stream-related functions.
- merge 3 patches into 1, as new sctp_stream has the same name
with before.Signed-off-by: Xin Long
Reviewed-by: Marcelo Ricardo Leitner
Signed-off-by: David S. Miller
24 Dec, 2016
2 commits
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Currently if SCTP closes the receive window with window pressure, mostly
caused by excessive skb overhead on payload/overheads ratio, SCTP will
close the window abruptly while saving the delta on rwnd_press. It will
start recovering rwnd as the chunks are consumed by the application and
the rwnd_press will be only recovered after rwnd reach the same value as
of rwnd_press, mostly to prevent silly window syndrome.Thing is, this is very inefficient with small data chunks, as with those
it will never reach back that value, and thus it will never recover from
such pressure. This means that we will not issue window updates when
recovering from 0 window and will rely on a sender retransmit to notice
it.The fix here is to remove such threshold, as no value is good enough: it
depends on the (avg) chunk sizes being used.Test with netperf -t SCTP_STREAM -- -m 1, and trigger 0 window by
sending SIGSTOP to netserver, sleep 1.2, and SIGCONT.
Rate limited to 845kbps, for visibility. Capture done at netserver side.Previously:
01.500751 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632372996] [a_rwnd 99153] [
01.500752 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632372997] [SID: 0] [SS
01.517471 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373010] [SID: 0] [SS
01.517483 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373009] [a_rwnd 0] [#gap
01.517485 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373083] [SID: 0] [SS
01.517488 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373009] [a_rwnd 0] [#gap
01.534168 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373096] [SID: 0] [SS
01.534180 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373009] [a_rwnd 0] [#gap
01.534181 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373169] [SID: 0] [SS
01.534185 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373009] [a_rwnd 0] [#gap
02.525978 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373010] [SID: 0] [SS
02.526021 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373009] [a_rwnd 0] [#gap
(window update missed)
04.573807 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373010] [SID: 0] [SS
04.779370 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373082] [a_rwnd 859] [#g
04.789162 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373083] [SID: 0] [SS
04.789323 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373156] [SID: 0] [SS
04.789372 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373228] [a_rwnd 786] [#gAfter:
02.568957 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098728] [a_rwnd 99153]
02.568961 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098729] [SID: 0] [S
02.585631 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098742] [SID: 0] [S
02.585666 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 0] [#ga
02.585671 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098815] [SID: 0] [S
02.585683 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 0] [#ga
02.602330 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098828] [SID: 0] [S
02.602359 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 0] [#ga
02.602363 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098901] [SID: 0] [S
02.602372 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 0] [#ga
03.600788 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098742] [SID: 0] [S
03.600830 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 0] [#ga
03.619455 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 13508]
03.619479 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 27017]
03.619497 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 40526]
03.619516 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 54035]
03.619533 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 67544]
03.619552 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 81053]
03.619570 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 94562]
(following data transmission triggered by window updates above)
03.633504 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098742] [SID: 0] [S
03.836445 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098814] [a_rwnd 100000]
03.843125 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098815] [SID: 0] [S
03.843285 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098888] [SID: 0] [S
03.843345 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098960] [a_rwnd 99894]
03.856546 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098961] [SID: 0] [S
03.866450 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490099011] [SID: 0] [SSigned-off-by: Marcelo Ricardo Leitner
Signed-off-by: David S. Miller -
It's possible that we receive a packet that is larger than current
window. If it's the first packet in this way, it will cause it to
increase rwnd_over. Then, if we receive another data chunk (specially as
SCTP allows you to have one data chunk in flight even during 0 window),
rwnd_over will be overwritten instead of added to.In the long run, this could cause the window to grow bigger than its
initial size, as rwnd_over would be charged only for the last received
data chunk while the code will try open the window for all packets that
were received and had its value in rwnd_over overwritten. This, then,
can lead to the worsening of payload/buffer ratio and cause rwnd_press
to kick in more often.The fix is to sum it too, same as is done for rwnd_press, so that if we
receive 3 chunks after closing the window, we still have to release that
same amount before re-opening it.Log snippet from sctp_test exhibiting the issue:
[ 146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000
rwnd decreased by 1 to (0, 1, 114221)
[ 146.209232] sctp: sctp_assoc_rwnd_decrease:
association:ffff88013928e000 has asoc->rwnd:0, asoc->rwnd_over:1!
[ 146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000
rwnd decreased by 1 to (0, 1, 114221)
[ 146.209232] sctp: sctp_assoc_rwnd_decrease:
association:ffff88013928e000 has asoc->rwnd:0, asoc->rwnd_over:1!
[ 146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000
rwnd decreased by 1 to (0, 1, 114221)
[ 146.209232] sctp: sctp_assoc_rwnd_decrease:
association:ffff88013928e000 has asoc->rwnd:0, asoc->rwnd_over:1!
[ 146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000
rwnd decreased by 1 to (0, 1, 114221)Signed-off-by: Marcelo Ricardo Leitner
Signed-off-by: David S. Miller
17 Nov, 2016
1 commit
-
Now sctp transport rhashtable uses hash(lport, dport, daddr) as the key
to hash a node to one chain. If in one host thousands of assocs connect
to one server with the same lport and different laddrs (although it's
not a normal case), all the transports would be hashed into the same
chain.It may cause to keep returning -EBUSY when inserting a new node, as the
chain is too long and sctp inserts a transport node in a loop, which
could even lead to system hangs there.The new rhlist interface works for this case that there are many nodes
with the same key in one chain. It puts them into a list then makes this
list be as a node of the chain.This patch is to replace rhashtable_ interface with rhltable_ interface.
Since a chain would not be too long and it would not return -EBUSY with
this fix when inserting a node, the reinsert loop is also removed here.Signed-off-by: Xin Long
Acked-by: Neil Horman
Acked-by: Marcelo Ricardo Leitner
Signed-off-by: David S. Miller
22 Sep, 2016
1 commit
-
To something more meaningful these days, specially because this is
working on packet headers or lengths and which are not tied to any CPU
arch but to the protocol itself.So, WORD_TRUNC becomes SCTP_TRUNC4 and WORD_ROUND becomes SCTP_PAD4.
Reported-by: David Laight
Reported-by: David Miller
Signed-off-by: Marcelo Ricardo Leitner
Signed-off-by: David S. Miller
12 Jul, 2016
1 commit
-
According to section 4.5 of rfc7496, prsctp_enable should be per asoc.
We will add prsctp_enable to both asoc and ep, and replace the places
where it used net.sctp->prsctp_enable with asoc->prsctp_enable.ep->prsctp_enable will be initialized with net.sctp->prsctp_enable, and
asoc->prsctp_enable will be initialized with ep->prsctp_enable. We can
also modify it's value through sockopt SCTP_PR_SUPPORTED.Signed-off-by: Xin Long
Signed-off-by: David S. Miller
21 Mar, 2016
1 commit
-
SCTP is a protocol that is aligned to a word (4 bytes). Thus using bare
MTU can sometimes return values that are not aligned, like for loopback,
which is 65536 but ipv4_mtu() limits that to 65535. This mis-alignment
will cause the last non-aligned bytes to never be used and can cause
issues with congestion control.So it's better to just consider a lower MTU and keep congestion control
calcs saner as they are based on PMTU.Same applies to icmp frag needed messages, which is also fixed by this
patch.One other effect of this is the inability to send MTU-sized packet
without queueing or fragmentation and without hitting Nagle. As the
check performed at sctp_packet_can_append_data():if (chunk->skb->len + q->out_qlen >= transport->pathmtu - packet->overhead)
/* Enough data queued to fill a packet */
return SCTP_XMIT_OK;with the above example of MTU, if there are no other messages queued,
one cannot send a packet that just fits one packet (65532 bytes) and
without causing DATA chunk fragmentation or a delay.v2:
- Added WORD_TRUNC macroSigned-off-by: Marcelo Ricardo Leitner
Signed-off-by: David S. Miller
14 Mar, 2016
2 commits
-
Currently sctp_sendmsg() triggers some calls that will allocate memory
with GFP_ATOMIC even when not necessary. In the case of
sctp_packet_transmit it will allocate a linear skb that will be used to
construct the packet and this may cause sends to fail due to ENOMEM more
often than anticipated specially with big MTUs.This patch thus allows it to inherit gfp flags from upper calls so that
it can use GFP_KERNEL if it was triggered by a sctp_sendmsg call or
similar. All others, like retransmits or flushes started from BH, are
still allocated using GFP_ATOMIC.In netperf tests this didn't result in any performance drawbacks when
memory is not too fragmented and made it trigger ENOMEM way less often.Signed-off-by: Marcelo Ricardo Leitner
Signed-off-by: David S. Miller -
prior to this patch, at the beginning if we have two paths in one assoc,
they may have the same params other than the last_time_heard, it will try
the paths like this:1st cycle
try trans1 fail.
then trans2 is selected.(cause it's last_time_heard is after trans1).2nd cycle:
try trans2 fail
then trans2 is selected.(cause it's last_time_heard is after trans1).3rd cycle:
try trans2 fail
then trans2 is selected.(cause it's last_time_heard is after trans1).....
trans1 will never have change to be selected, which is not what we expect.
we should keeping round robin all the paths if they are just added at the
beginning.So at first every tranport's last_time_heard should be initialized 0, so
that we ensure they have the same value at the beginning, only by this,
all the transports could get equal chance to be selected.Then for sctp_trans_elect_best, it should return the trans_next one when
*trans == *trans_next, so that we can try next if it fails, but now it
always return trans. so we can fix it by exchanging these two params when
we calls sctp_trans_elect_tie().Fixes: 4c47af4d5eb2 ('net: sctp: rework multihoming retransmission path selection to rfc4960')
Signed-off-by: Xin Long
Acked-by: Daniel Borkmann
Acked-by: Marcelo Ricardo Leitner
Signed-off-by: David S. Miller
06 Jan, 2016
1 commit
-
apply lookup apis to two functions, for __sctp_endpoint_lookup_assoc
and __sctp_lookup_association, it's invoked in the protection of sock
lock, it will be safe, but sctp_lookup_association need to call
rcu_read_lock() and to detect the t->dead to protect it.Signed-off-by: Xin Long
Signed-off-by: Marcelo Ricardo Leitner
Signed-off-by: David S. Miller
07 Nov, 2015
1 commit
-
…d avoiding waking kswapd
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts. They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve". __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".Over time, callers had a requirement to not block when fallback options
were available. Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative. High priority users continue to use
__GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim. __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.This patch then converts a number of sites
o __GFP_ATOMIC is used by callers that are high priority and have memory
pools for those requests. GFP_ATOMIC uses this flag.o Callers that have a limited mempool to guarantee forward progress clear
__GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
into this category where kswapd will still be woken but atomic reserves
are not used as there is a one-entry mempool to guarantee progress.o Callers that are checking if they are non-blocking should use the
helper gfpflags_allow_blocking() where possible. This is because
checking for __GFP_WAIT as was done historically now can trigger false
positives. Some exceptions like dm-crypt.c exist where the code intent
is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
flag manipulations.o Callers that built their own GFP flags instead of starting with GFP_KERNEL
and friends now also need to specify __GFP_KSWAPD_RECLAIM.The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL. They may
now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
29 Sep, 2015
1 commit
-
Seemingly innocuous sctp_trans_state_to_prio_map[] array
is way bigger than it looks, since
"[SCTP_UNKNOWN] = 2" expands into "[0xffff] = 2" !This patch replaces it with switch() statement.
Signed-off-by: Denys Vlasenko
CC: Vlad Yasevich
CC: Neil Horman
CC: Marcelo Ricardo Leitner
CC: linux-sctp@vger.kernel.org
CC: netdev@vger.kernel.org
CC: linux-kernel@vger.kernel.org
Acked-by: Marcelo Ricardo Leitner
Acked-by: Neil Horman
Signed-off-by: David S. Miller
03 Feb, 2015
1 commit
-
The kfree() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring
Acked-By: Neil Horman
Signed-off-by: David S. Miller
27 Jan, 2015
1 commit
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When hitting an INIT collision case during the 4WHS with AUTH enabled, as
already described in detail in commit 1be9a950c646 ("net: sctp: inherit
auth_capable on INIT collisions"), it can happen that we occasionally
still remotely trigger the following panic on server side which seems to
have been uncovered after the fix from commit 1be9a950c646 ...[ 533.876389] BUG: unable to handle kernel paging request at 00000000ffffffff
[ 533.913657] IP: [] __kmalloc+0x95/0x230
[ 533.940559] PGD 5030f2067 PUD 0
[ 533.957104] Oops: 0000 [#1] SMP
[ 533.974283] Modules linked in: sctp mlx4_en [...]
[ 534.939704] Call Trace:
[ 534.951833] [] ? crypto_init_shash_ops+0x60/0xf0
[ 534.984213] [] crypto_init_shash_ops+0x60/0xf0
[ 535.015025] [] __crypto_alloc_tfm+0x6d/0x170
[ 535.045661] [] crypto_alloc_base+0x4c/0xb0
[ 535.074593] [] ? _raw_spin_lock_bh+0x12/0x50
[ 535.105239] [] sctp_inet_listen+0x161/0x1e0 [sctp]
[ 535.138606] [] SyS_listen+0x9d/0xb0
[ 535.166848] [] system_call_fastpath+0x16/0x1b... or depending on the the application, for example this one:
[ 1370.026490] BUG: unable to handle kernel paging request at 00000000ffffffff
[ 1370.026506] IP: [] kmem_cache_alloc+0x75/0x1d0
[ 1370.054568] PGD 633c94067 PUD 0
[ 1370.070446] Oops: 0000 [#1] SMP
[ 1370.085010] Modules linked in: sctp kvm_amd kvm [...]
[ 1370.963431] Call Trace:
[ 1370.974632] [] ? SyS_epoll_ctl+0x53f/0x960
[ 1371.000863] [] SyS_epoll_ctl+0x53f/0x960
[ 1371.027154] [] ? anon_inode_getfile+0xd3/0x170
[ 1371.054679] [] ? __alloc_fd+0xa7/0x130
[ 1371.080183] [] system_call_fastpath+0x16/0x1bWith slab debugging enabled, we can see that the poison has been overwritten:
[ 669.826368] BUG kmalloc-128 (Tainted: G W ): Poison overwritten
[ 669.826385] INFO: 0xffff880228b32e50-0xffff880228b32e50. First byte 0x6a instead of 0x6b
[ 669.826414] INFO: Allocated in sctp_auth_create_key+0x23/0x50 [sctp] age=3 cpu=0 pid=18494
[ 669.826424] __slab_alloc+0x4bf/0x566
[ 669.826433] __kmalloc+0x280/0x310
[ 669.826453] sctp_auth_create_key+0x23/0x50 [sctp]
[ 669.826471] sctp_auth_asoc_create_secret+0xcb/0x1e0 [sctp]
[ 669.826488] sctp_auth_asoc_init_active_key+0x68/0xa0 [sctp]
[ 669.826505] sctp_do_sm+0x29d/0x17c0 [sctp] [...]
[ 669.826629] INFO: Freed in kzfree+0x31/0x40 age=1 cpu=0 pid=18494
[ 669.826635] __slab_free+0x39/0x2a8
[ 669.826643] kfree+0x1d6/0x230
[ 669.826650] kzfree+0x31/0x40
[ 669.826666] sctp_auth_key_put+0x19/0x20 [sctp]
[ 669.826681] sctp_assoc_update+0x1ee/0x2d0 [sctp]
[ 669.826695] sctp_do_sm+0x674/0x17c0 [sctp]Since this only triggers in some collision-cases with AUTH, the problem at
heart is that sctp_auth_key_put() on asoc->asoc_shared_key is called twice
when having refcnt 1, once directly in sctp_assoc_update() and yet again
from within sctp_auth_asoc_init_active_key() via sctp_assoc_update() on
the already kzfree'd memory, which is also consistent with the observation
of the poison decrease from 0x6b to 0x6a (note: the overwrite is detected
at a later point in time when poison is checked on new allocation).Reference counting of auth keys revisited:
Shared keys for AUTH chunks are being stored in endpoints and associations
in endpoint_shared_keys list. On endpoint creation, a null key is being
added; on association creation, all endpoint shared keys are being cached
and thus cloned over to the association. struct sctp_shared_key only holds
a pointer to the actual key bytes, that is, struct sctp_auth_bytes which
keeps track of users internally through refcounting. Naturally, on assoc
or enpoint destruction, sctp_shared_key are being destroyed directly and
the reference on sctp_auth_bytes dropped.User space can add keys to either list via setsockopt(2) through struct
sctp_authkey and by passing that to sctp_auth_set_key() which replaces or
adds a new auth key. There, sctp_auth_create_key() creates a new sctp_auth_bytes
with refcount 1 and in case of replacement drops the reference on the old
sctp_auth_bytes. A key can be set active from user space through setsockopt()
on the id via sctp_auth_set_active_key(), which iterates through either
endpoint_shared_keys and in case of an assoc, invokes (one of various places)
sctp_auth_asoc_init_active_key().sctp_auth_asoc_init_active_key() computes the actual secret from local's
and peer's random, hmac and shared key parameters and returns a new key
directly as sctp_auth_bytes, that is asoc->asoc_shared_key, plus drops
the reference if there was a previous one. The secret, which where we
eventually double drop the ref comes from sctp_auth_asoc_set_secret() with
intitial refcount of 1, which also stays unchanged eventually in
sctp_assoc_update(). This key is later being used for crypto layer to
set the key for the hash in crypto_hash_setkey() from sctp_auth_calculate_hmac().To close the loop: asoc->asoc_shared_key is freshly allocated secret
material and independant of the sctp_shared_key management keeping track
of only shared keys in endpoints and assocs. Hence, also commit 4184b2a79a76
("net: sctp: fix memory leak in auth key management") is independant of
this bug here since it concerns a different layer (though same structures
being used eventually). asoc->asoc_shared_key is reference dropped correctly
on assoc destruction in sctp_association_free() and when active keys are
being replaced in sctp_auth_asoc_init_active_key(), it always has a refcount
of 1. Hence, it's freed prematurely in sctp_assoc_update(). Simple fix is
to remove that sctp_auth_key_put() from there which fixes these panics.Fixes: 730fc3d05cd4 ("[SCTP]: Implete SCTP-AUTH parameter processing")
Signed-off-by: Daniel Borkmann
Acked-by: Vlad Yasevich
Acked-by: Neil Horman
Signed-off-by: David S. Miller
15 Oct, 2014
1 commit
-
When receiving a e.g. semi-good formed connection scan in the
form of ...-------------- INIT[ASCONF; ASCONF_ACK] ------------->
... where ASCONF_a equals ASCONF_b chunk (at least both serials
need to be equal), we panic an SCTP server!The problem is that good-formed ASCONF chunks that we reply with
ASCONF_ACK chunks are cached per serial. Thus, when we receive a
same ASCONF chunk twice (e.g. through a lost ASCONF_ACK), we do
not need to process them again on the server side (that was the
idea, also proposed in the RFC). Instead, we know it was cached
and we just resend the cached chunk instead. So far, so good.Where things get nasty is in SCTP's side effect interpreter, that
is, sctp_cmd_interpreter():While incoming ASCONF_a (chunk = event_arg) is being marked
!end_of_packet and !singleton, and we have an association context,
we do not flush the outqueue the first time after processing the
ASCONF_ACK singleton chunk via SCTP_CMD_REPLY. Instead, we keep it
queued up, although we set local_cork to 1. Commit 2e3216cd54b1
changed the precedence, so that as long as we get bundled, incoming
chunks we try possible bundling on outgoing queue as well. Before
this commit, we would just flush the output queue.Now, while ASCONF_a's ASCONF_ACK sits in the corked outq, we
continue to process the same ASCONF_b chunk from the packet. As
we have cached the previous ASCONF_ACK, we find it, grab it and
do another SCTP_CMD_REPLY command on it. So, effectively, we rip
the chunk->list pointers and requeue the same ASCONF_ACK chunk
another time. Since we process ASCONF_b, it's correctly marked
with end_of_packet and we enforce an uncork, and thus flush, thus
crashing the kernel.Fix it by testing if the ASCONF_ACK is currently pending and if
that is the case, do not requeue it. When flushing the output
queue we may relink the chunk for preparing an outgoing packet,
but eventually unlink it when it's copied into the skb right
before transmission.Joint work with Vlad Yasevich.
Fixes: 2e3216cd54b1 ("sctp: Follow security requirement of responding with 1 packet")
Signed-off-by: Daniel Borkmann
Signed-off-by: Vlad Yasevich
Signed-off-by: David S. Miller
23 Aug, 2014
2 commits
-
In SCTP, selection of active (T.ACT) and retransmission (T.RET)
transports is being done whenever transport control operations
(UP, DOWN, PF, ...) are engaged through sctp_assoc_control_transport().Commits 4c47af4d5eb2 ("net: sctp: rework multihoming retransmission
path selection to rfc4960") and a7288c4dd509 ("net: sctp: improve
sctp_select_active_and_retran_path selection") have both improved
it towards a more fine-grained and optimal path selection.Currently, the selection algorithm for T.ACT and T.RET is as follows:
1) Elect the two most recently used ACTIVE transports T1, T2 for
T.ACT, T.RET, where T.ACT
T1: p1p1 (10.0.10.10) .'`) p1p1 (10.0.10.12) (_ . ) p1p2 (10.0.10.22)net.sctp.rto_min = 1000
net.sctp.path_max_retrans = 2
net.sctp.pf_retrans = 0
net.sctp.hb_interval = 1000T.PRI is permanently down, T2 is put briefly into PF state (e.g. due to
link flapping). Here, the first time transmission is sent over PF path
T2 as it's the only non-INACTIVE path, but the retransmitted data-chunks
are sent over the INACTIVE path T1 (T.PRI), which is not good.After the patch, it's choosing better transports in both cases by
modifying step 4):4) If none is ACTIVE, set T.ACT_newPF->INACTIVE and stays in INACTIVE just
for a very short while before going back ACTIVE, it will guarantee that
this path will be reselected for T.ACT/T.RET since T3 (PF) is not
available.Previously, this was not possible, as we would only select between T.PRI
and T.RET, and a possible T3 would be NULL due to the fact that we have
just transitioned T3 in sctp_assoc_control_transport() from PF->INACTIVE
and would select a suboptimal path when T.PRI/T.RET have worse properties.In the case that T.ACT_old permanently went to INACTIVE during this
transition and there's no PF path available, plus T.PRI and T.RET are
INACTIVE as well, we would now camp on T.ACT_old, but if everything is
being INACTIVE there's really not much we can do except hoping for a
successful HB to bring one of the transports back up again and, thus
cause a new selection through sctp_assoc_control_transport().Now both tests work fine:
Case 1:
1. T1 S(ACTIVE) T.ACT
T2 S(ACTIVE) T.RET2. T1 S(ACTIVE) T.ACT, T.RET
T2 S(PF)3. T1 S(ACTIVE) T.ACT, T.RET
T2 S(INACTIVE)5. T1 S(PF) T.ACT, T.RET
T2 S(INACTIVE)[ 5.1 T1 S(INACTIVE) T.ACT, T.RET
T2 S(INACTIVE) ]6. T1 S(ACTIVE) T.ACT, T.RET
T2 S(INACTIVE)7. T1 S(ACTIVE) T.ACT
T2 S(ACTIVE) T.RETCase 2:
1. T1 S(ACTIVE) T.ACT
T2 S(ACTIVE) T.RET2. T1 S(PF)
T2 S(ACTIVE) T.ACT, T.RET3. T1 S(INACTIVE)
T2 S(ACTIVE) T.ACT, T.RET5. T1 S(INACTIVE)
T2 S(PF) T.ACT, T.RET[ 5.1 T1 S(INACTIVE)
T2 S(INACTIVE) T.ACT, T.RET ]6. T1 S(INACTIVE)
T2 S(ACTIVE) T.ACT, T.RET7. T1 S(ACTIVE) T.ACT
T2 S(ACTIVE) T.RETSigned-off-by: Daniel Borkmann
Acked-by: Neil Horman
Acked-by: Vlad Yasevich
Signed-off-by: David S. Miller -
When both transports are the same, we don't have to go down that
road only to realize that we will return the very same transport.
We are guaranteed that curr is always non-NULL. Therefore, just
short-circuit this special case.Signed-off-by: Daniel Borkmann
Acked-by: Neil Horman
Acked-by: Vlad Yasevich
Signed-off-by: David S. Miller
22 Aug, 2014
1 commit
-
Since the transport has always been in state SCTP_UNCONFIRMED, it
therefore wasn't active before and hasn't been used before, and it
always has been, so it is unnecessary to bug the user with a
notification.Reported-by: Deepak Khandelwal
Suggested-by: Vlad Yasevich
Suggested-by: Michael Tuexen
Suggested-by: Daniel Borkmann
Signed-off-by: Zhu Yanjun
Acked-by: Vlad Yasevich
Acked-by: Daniel Borkmann
Signed-off-by: David S. Miller
23 Jul, 2014
1 commit
-
Jason reported an oops caused by SCTP on his ARM machine with
SCTP authentication enabled:Internal error: Oops: 17 [#1] ARM
CPU: 0 PID: 104 Comm: sctp-test Not tainted 3.13.0-68744-g3632f30c9b20-dirty #1
task: c6eefa40 ti: c6f52000 task.ti: c6f52000
PC is at sctp_auth_calculate_hmac+0xc4/0x10c
LR is at sg_init_table+0x20/0x38
pc : [] lr : [] psr: 40000013
sp : c6f538e8 ip : 00000000 fp : c6f53924
r10: c6f50d80 r9 : 00000000 r8 : 00010000
r7 : 00000000 r6 : c7be4000 r5 : 00000000 r4 : c6f56254
r3 : c00c8170 r2 : 00000001 r1 : 00000008 r0 : c6f1e660
Flags: nZcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Control: 0005397f Table: 06f28000 DAC: 00000015
Process sctp-test (pid: 104, stack limit = 0xc6f521c0)
Stack: (0xc6f538e8 to 0xc6f54000)
[...]
Backtrace:
[] (sctp_auth_calculate_hmac+0x0/0x10c) from [] (sctp_packet_transmit+0x33c/0x5c8)
[] (sctp_packet_transmit+0x0/0x5c8) from [] (sctp_outq_flush+0x7fc/0x844)
[] (sctp_outq_flush+0x0/0x844) from [] (sctp_outq_uncork+0x24/0x28)
[] (sctp_outq_uncork+0x0/0x28) from [] (sctp_side_effects+0x1134/0x1220)
[] (sctp_side_effects+0x0/0x1220) from [] (sctp_do_sm+0xac/0xd4)
[] (sctp_do_sm+0x0/0xd4) from [] (sctp_assoc_bh_rcv+0x118/0x160)
[] (sctp_assoc_bh_rcv+0x0/0x160) from [] (sctp_inq_push+0x6c/0x74)
[] (sctp_inq_push+0x0/0x74) from [] (sctp_rcv+0x7d8/0x888)While we already had various kind of bugs in that area
ec0223ec48a9 ("net: sctp: fix sctp_sf_do_5_1D_ce to verify if
we/peer is AUTH capable") and b14878ccb7fa ("net: sctp: cache
auth_enable per endpoint"), this one is a bit of a different
kind.Giving a bit more background on why SCTP authentication is
needed can be found in RFC4895:SCTP uses 32-bit verification tags to protect itself against
blind attackers. These values are not changed during the
lifetime of an SCTP association.Looking at new SCTP extensions, there is the need to have a
method of proving that an SCTP chunk(s) was really sent by
the original peer that started the association and not by a
malicious attacker.To cause this bug, we're triggering an INIT collision between
peers; normal SCTP handshake where both sides intent to
authenticate packets contains RANDOM; CHUNKS; HMAC-ALGO
parameters that are being negotiated among peers:---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ---------->
...Since such collisions can also happen with verification tags,
the RFC4895 for AUTH rather vaguely says under section 6.1:In case of INIT collision, the rules governing the handling
of this Random Number follow the same pattern as those for
the Verification Tag, as explained in Section 5.2.4 of
RFC 2960 [5]. Therefore, each endpoint knows its own Random
Number and the peer's Random Number after the association
has been established.In RFC2960, section 5.2.4, we're eventually hitting Action B:
B) In this case, both sides may be attempting to start an
association at about the same time but the peer endpoint
started its INIT after responding to the local endpoint's
INIT. Thus it may have picked a new Verification Tag not
being aware of the previous Tag it had sent this endpoint.
The endpoint should stay in or enter the ESTABLISHED
state but it MUST update its peer's Verification Tag from
the State Cookie, stop any init or cookie timers that may
running and send a COOKIE ACK.In other words, the handling of the Random parameter is the
same as behavior for the Verification Tag as described in
Action B of section 5.2.4.Looking at the code, we exactly hit the sctp_sf_do_dupcook_b()
case which triggers an SCTP_CMD_UPDATE_ASSOC command to the
side effect interpreter, and in fact it properly copies over
peer_{random, hmacs, chunks} parameters from the newly created
association to update the existing one.Also, the old asoc_shared_key is being released and based on
the new params, sctp_auth_asoc_init_active_key() updated.
However, the issue observed in this case is that the previous
asoc->peer.auth_capable was 0, and has *not* been updated, so
that instead of creating a new secret, we're doing an early
return from the function sctp_auth_asoc_init_active_key()
leaving asoc->asoc_shared_key as NULL. However, we now have to
authenticate chunks from the updated chunk list (e.g. COOKIE-ACK).That in fact causes the server side when responding with ...
active_key_id is still inherited from the
endpoint, and the same as encoded into the chunk, it uses
asoc->asoc_shared_key, which is still NULL, as an asoc_key
and dereferences it in ...crypto_hash_setkey(desc.tfm, &asoc_key->data[0], asoc_key->len)
... causing an oops. All this happens because sctp_make_cookie_ack()
called with the *new* association has the peer.auth_capable=1
and therefore marks the chunk with auth=1 after checking
sctp_auth_send_cid(), but it is *actually* sent later on over
the then *updated* association's transport that didn't initialize
its shared key due to peer.auth_capable=0. Since control chunks
in that case are not sent by the temporary association which
are scheduled for deletion, they are issued for xmit via
SCTP_CMD_REPLY in the interpreter with the context of the
*updated* association. peer.auth_capable was 0 in the updated
association (which went from COOKIE_WAIT into ESTABLISHED state),
since all previous processing that performed sctp_process_init()
was being done on temporary associations, that we eventually
throw away each time.The correct fix is to update to the new peer.auth_capable
value as well in the collision case via sctp_assoc_update(),
so that in case the collision migrated from 0 -> 1,
sctp_auth_asoc_init_active_key() can properly recalculate
the secret. This therefore fixes the observed server panic.Fixes: 730fc3d05cd4 ("[SCTP]: Implete SCTP-AUTH parameter processing")
Reported-by: Jason Gunthorpe
Signed-off-by: Daniel Borkmann
Tested-by: Jason Gunthorpe
Cc: Vlad Yasevich
Acked-by: Vlad Yasevich
Signed-off-by: David S. Miller
13 Jun, 2014
1 commit
-
Consider the scenario:
For a TCP-style socket, while processing the COOKIE_ECHO chunk in
sctp_sf_do_5_1D_ce(), after it has passed a series of sanity check,
a new association would be created in sctp_unpack_cookie(), but afterwards,
some processing maybe failed, and sctp_association_free() will be called to
free the previously allocated association, in sctp_association_free(),
sk_ack_backlog value is decremented for this socket, since the initial
value for sk_ack_backlog is 0, after the decrement, it will be 65535,
a wrap-around problem happens, and if we want to establish new associations
afterward in the same socket, ABORT would be triggered since sctp deem the
accept queue as full.
Fix this issue by only decrementing sk_ack_backlog for associations in
the endpoint's list.Fix-suggested-by: Neil Horman
Signed-off-by: Xufeng Zhang
Acked-by: Daniel Borkmann
Acked-by: Vlad Yasevich
Signed-off-by: David S. Miller
12 Jun, 2014
1 commit
-
This fixes the following sparse warning:
net/sctp/associola.c:1556:29: warning: incorrect type in initializer (different base types)
net/sctp/associola.c:1556:29: expected bool [unsigned] [usertype] preload
net/sctp/associola.c:1556:29: got restricted gfp_tSigned-off-by: Daniel Borkmann
Signed-off-by: David S. Miller