sctp: implement prsctp PRIO policy

prsctp PRIO policy is a policy to abandon lower priority chunks when
asoc doesn't have enough snd buffer, so that the current chunk with
higher priority can be que

sctp: implement prsctp PRIO policy

prsctp PRIO policy is a policy to abandon lower priority chunks when
asoc doesn't have enough snd buffer, so that the current chunk with
higher priority can be queued successfully.

Similar to TTL/RTX policy, we will set the priority of the chunk to
prsctp_param with sinfo->sinfo_timetolive in sctp_set_prsctp_policy().
So if PRIO policy is enabled, msg->expire_at won't work.

asoc->sent_cnt_removable will record how many chunks can be checked to
remove. If priority policy is enabled, when the chunk is queued into
the out_queue, we will increase sent_cnt_removable. When the chunk is
moved to abandon_queue or dequeue and free, we will decrease
sent_cnt_removable.

In sctp_sendmsg, we will check if there is enough snd buffer for current
msg and if sent_cnt_removable is not 0. Then try to abandon chunks in
sctp_prune_prsctp when sendmsg from the retransmit/transmited queue, and
free chunks from out_queue in right order until the abandon+free size >
msg_len - sctp_wfree. For the abandon size, we have to wait until it
sends FORWARD TSN, receives the sack and the chunks are really freed.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: implement prsctp RTX policy

prsctp RTX policy is a policy to abandon chunks when they are
retransmitted beyond the max count.

This patch uses sent_count to count how many times one chunk has

sctp: implement prsctp RTX policy

prsctp RTX policy is a policy to abandon chunks when they are
retransmitted beyond the max count.

This patch uses sent_count to count how many times one chunk has
been sent, and prsctp_param is the max rtx count, which is from
sinfo->sinfo_timetolive in sctp_set_prsctp_policy(). So similar
to TTL policy, if RTX policy is enabled, msg->expire_at won't
work.

Then in sctp_chunk_abandoned, this patch checks if chunk->sent_count
is bigger than chunk->prsctp_param to abandon this chunk.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: implement prsctp TTL policy

prsctp TTL policy is a policy to abandon chunks when they expire
at the specific time in local stack. It's similar with expires_at
in struct sctp_datamsg.

This pat

sctp: implement prsctp TTL policy

prsctp TTL policy is a policy to abandon chunks when they expire
at the specific time in local stack. It's similar with expires_at
in struct sctp_datamsg.

This patch uses sinfo->sinfo_timetolive to set the specific time for
TTL policy. sinfo->sinfo_timetolive is also used for msg->expires_at.
So if prsctp_enable or TTL policy is not enabled, msg->expires_at
still works as before.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: add SCTP_PR_SUPPORTED on sctp sockopt

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

sctp: add SCTP_PR_SUPPORTED on sctp sockopt

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 <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: avoid refreshing heartbeat timer too often

Currently on high rate SCTP streams the heartbeat timer refresh can
consume quite a lot of resources as timer updates are costly and it
contains a ra

sctp: avoid refreshing heartbeat timer too often

Currently on high rate SCTP streams the heartbeat timer refresh can
consume quite a lot of resources as timer updates are costly and it
contains a random factor, which a) is also costly and b) invalidates
mod_timer() optimization for not editing a timer to the same value.
It may even cause the timer to be slightly advanced, for no good reason.

As suggested by David Laight this patch now removes this timer update
from hot path by leaving the timer on and re-evaluating upon its
expiration if the heartbeat is still needed or not, similarly to what is
done for TCP. If it's not needed anymore the timer is re-scheduled to
the new timeout, considering the time already elapsed.

For this, we now record the last tx timestamp per transport, updated in
the same spots as hb timer was restarted on tx. Also split up
sctp_transport_reset_timers into sctp_transport_reset_t3_rtx and
sctp_transport_reset_hb_timer, so we can re-arm T3 without re-arming the
heartbeat one.

On loopback with MTU of 65535 and data chunks with 1636, so that we
have a considerable amount of chunks without stressing system calls,
netperf -t SCTP_STREAM -l 30, perf looked like this before:

Samples: 103K of event 'cpu-clock', Event count (approx.): 25833000000
Overhead Command Shared Object Symbol
+ 6,15% netperf [kernel.vmlinux] [k] copy_user_enhanced_fast_string
- 5,43% netperf [kernel.vmlinux] [k] _raw_write_unlock_irqrestore
- _raw_write_unlock_irqrestore
- 96,54% _raw_spin_unlock_irqrestore
- 36,14% mod_timer
+ 97,24% sctp_transport_reset_timers
+ 2,76% sctp_do_sm
+ 33,65% __wake_up_sync_key
+ 28,77% sctp_ulpq_tail_event
+ 1,40% del_timer
- 1,84% mod_timer
+ 99,03% sctp_transport_reset_timers
+ 0,97% sctp_do_sm
+ 1,50% sctp_ulpq_tail_event

And after this patch, now with netperf -l 60:

Samples: 230K of event 'cpu-clock', Event count (approx.): 57707250000
Overhead Command Shared Object Symbol
+ 5,65% netperf [kernel.vmlinux] [k] memcpy_erms
+ 5,59% netperf [kernel.vmlinux] [k] copy_user_enhanced_fast_string
- 5,05% netperf [kernel.vmlinux] [k] _raw_spin_unlock_irqrestore
- _raw_spin_unlock_irqrestore
+ 49,89% __wake_up_sync_key
+ 45,68% sctp_ulpq_tail_event
- 2,85% mod_timer
+ 76,51% sctp_transport_reset_t3_rtx
+ 23,49% sctp_do_sm
+ 1,55% del_timer
+ 2,50% netperf [sctp] [k] sctp_datamsg_from_user
+ 2,26% netperf [sctp] [k] sctp_sendmsg

Throughput-wise, from 6800mbps without the patch to 7050mbps with it,
~3.7%.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: allow sctp_transmit_packet and others to use gfp

Currently sctp_sendmsg() triggers some calls that will allocate memory
with GFP_ATOMIC even when not necessary. In the case of
sctp_packet_tran

sctp: allow sctp_transmit_packet and others to use gfp

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 <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: fix copying more bytes than expected in sctp_add_bind_addr

Dmitry reported that sctp_add_bind_addr may read more bytes than
expected in case the parameter is a IPv4 addr supplied by the user
t

sctp: fix copying more bytes than expected in sctp_add_bind_addr

Dmitry reported that sctp_add_bind_addr may read more bytes than
expected in case the parameter is a IPv4 addr supplied by the user
through calls such as sctp_bindx_add(), because it always copies
sizeof(union sctp_addr) while the buffer may be just a struct
sockaddr_in, which is smaller.

This patch then fixes it by limiting the memcpy to the min between the
union size and a (new parameter) provided addr size. Where possible this
parameter still is the size of that union, except for reading from
user-provided buffers, which then it accounts for protocol type.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: Use shash

This patch replaces uses of the long obsolete hash interface with
shash.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: David S. Miller <davem@davemloft.net>

sctp: use the same clock as if sock source timestamps were on

SCTP echoes a cookie o INIT ACK chunks that contains a timestamp, for
detecting stale cookies. This cookie is echoed back to the server

sctp: use the same clock as if sock source timestamps were on

SCTP echoes a cookie o INIT ACK chunks that contains a timestamp, for
detecting stale cookies. This cookie is echoed back to the server by the
client and then that timestamp is checked.

Thing is, if the listening socket is using packet timestamping, the
cookie is encoded with ktime_get() value and checked against
ktime_get_real(), as done by __net_timestamp().

The fix is to sctp also use ktime_get_real(), so we can compare bananas
with bananas later no matter if packet timestamping was enabled or not.

Fixes: 52db882f3fc2 ("net: sctp: migrate cookie life from timeval to ktime")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: sctp: avoid incorrect time_t use

We want to avoid using time_t in the kernel because of the y2038
overflow problem. The use in sctp is not for storing seconds at
all, but instead uses microseco

net: sctp: avoid incorrect time_t use

We want to avoid using time_t in the kernel because of the y2038
overflow problem. The use in sctp is not for storing seconds at
all, but instead uses microseconds and is passed as 32-bit
on all machines.

This patch changes the type to u32, which better fits the use.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: linux-sctp@vger.kernel.org
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: ASCONF-ACK with Unresolvable Address should be sent

RFC 5061:
This is an opaque integer assigned by the sender to identify each
request parameter. The receiver of the ASCONF Chunk wil

sctp: ASCONF-ACK with Unresolvable Address should be sent

RFC 5061:
This is an opaque integer assigned by the sender to identify each
request parameter. The receiver of the ASCONF Chunk will copy this
32-bit value into the ASCONF Response Correlation ID field of the
ASCONF-ACK response parameter. The sender of the ASCONF can use this
same value in the ASCONF-ACK to find which request the response is
for. Note that the receiver MUST NOT change this 32-bit value.

Address Parameter: TLV

This field contains an IPv4 or IPv6 address parameter, as described
in Section 3.3.2.1 of [RFC4960].

ASCONF chunk with Error Cause Indication Parameter (Unresolvable Address)
should be sent if the Delete IP Address is not part of the association.

Endpoint A Endpoint B
(ESTABLISHED) (ESTABLISHED)

ASCONF ----------------->
(Delete IP Address)
<----------------- ASCONF-ACK
(Unresolvable Address)

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: asconf's process should verify address parameter is in the beginning

in sctp_process_asconf(), we get address parameter from the beginning of
the addip params. but we never check if it's reall

sctp: asconf's process should verify address parameter is in the beginning

in sctp_process_asconf(), we get address parameter from the beginning of
the addip params. but we never check if it's really there. if the addr
param is not there, it still can pass sctp_verify_asconf(), then to be
handled by sctp_process_asconf(), it will not be safe.

so add a code in sctp_verify_asconf() to check the address parameter is in
the beginning, or return false to send abort.

note that this can also detect multiple address parameters, and reject it.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: sctp: fix passing wrong parameter header to param_type2af in sctp_process_param

When making use of RFC5061, section 4.2.4. for setting the primary IP
address, we're passing a wrong parameter he

net: sctp: fix passing wrong parameter header to param_type2af in sctp_process_param

When making use of RFC5061, section 4.2.4. for setting the primary IP
address, we're passing a wrong parameter header to param_type2af(),
resulting always in NULL being returned.

At this point, param.p points to a sctp_addip_param struct, containing
a sctp_paramhdr (type = 0xc004, length = var), and crr_id as a correlation
id. Followed by that, as also presented in RFC5061 section 4.2.4., comes
the actual sctp_addr_param, which also contains a sctp_paramhdr, but
this time with the correct type SCTP_PARAM_IPV{4,6}_ADDRESS that
param_type2af() can make use of. Since we already hold a pointer to
addr_param from previous line, just reuse it for param_type2af().

Fixes: d6de3097592b ("[SCTP]: Add the handling of "Set Primary IP Address" parameter to INIT")
Signed-off-by: Saran Maruti Ramanara <saran.neti@telus.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

switch sctp_user_addto_chunk() and sctp_datamsg_from_user() to passing iov_iter

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

new helper: memcpy_from_msg()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

net: sctp: fix NULL pointer dereference in af->from_addr_param on malformed packet

An SCTP server doing ASCONF will panic on malformed INIT ping-of-death
in the form of:

------------ INIT[PARAM:

net: sctp: fix NULL pointer dereference in af->from_addr_param on malformed packet

An SCTP server doing ASCONF will panic on malformed INIT ping-of-death
in the form of:

------------ INIT[PARAM: SET_PRIMARY_IP] ------------>

While the INIT chunk parameter verification dissects through many things
in order to detect malformed input, it misses to actually check parameters
inside of parameters. E.g. RFC5061, section 4.2.4 proposes a 'set primary
IP address' parameter in ASCONF, which has as a subparameter an address
parameter.

So an attacker may send a parameter type other than SCTP_PARAM_IPV4_ADDRESS
or SCTP_PARAM_IPV6_ADDRESS, param_type2af() will subsequently return 0
and thus sctp_get_af_specific() returns NULL, too, which we then happily
dereference unconditionally through af->from_addr_param().

The trace for the log:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
IP: [<ffffffffa01e9c62>] sctp_process_init+0x492/0x990 [sctp]
PGD 0
Oops: 0000 [#1] SMP
[...]
Pid: 0, comm: swapper Not tainted 2.6.32-504.el6.x86_64 #1 Bochs Bochs
RIP: 0010:[<ffffffffa01e9c62>] [<ffffffffa01e9c62>] sctp_process_init+0x492/0x990 [sctp]
[...]
Call Trace:
<IRQ>
[<ffffffffa01f2add>] ? sctp_bind_addr_copy+0x5d/0xe0 [sctp]
[<ffffffffa01e1fcb>] sctp_sf_do_5_1B_init+0x21b/0x340 [sctp]
[<ffffffffa01e3751>] sctp_do_sm+0x71/0x1210 [sctp]
[<ffffffffa01e5c09>] ? sctp_endpoint_lookup_assoc+0xc9/0xf0 [sctp]
[<ffffffffa01e61f6>] sctp_endpoint_bh_rcv+0x116/0x230 [sctp]
[<ffffffffa01ee986>] sctp_inq_push+0x56/0x80 [sctp]
[<ffffffffa01fcc42>] sctp_rcv+0x982/0xa10 [sctp]
[<ffffffffa01d5123>] ? ipt_local_in_hook+0x23/0x28 [iptable_filter]
[<ffffffff8148bdc9>] ? nf_iterate+0x69/0xb0
[<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0
[<ffffffff8148bf86>] ? nf_hook_slow+0x76/0x120
[<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0
[...]

A minimal way to address this is to check for NULL as we do on all
other such occasions where we know sctp_get_af_specific() could
possibly return with NULL.

Fixes: d6de3097592b ("[SCTP]: Add the handling of "Set Primary IP Address" parameter to INIT")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: sctp: fix skb_over_panic when receiving malformed ASCONF chunks

Commit 6f4c618ddb0 ("SCTP : Add paramters validity check for
ASCONF chunk") added basic verification of ASCONF chunks, however,
i

net: sctp: fix skb_over_panic when receiving malformed ASCONF chunks

Commit 6f4c618ddb0 ("SCTP : Add paramters validity check for
ASCONF chunk") added basic verification of ASCONF chunks, however,
it is still possible to remotely crash a server by sending a
special crafted ASCONF chunk, even up to pre 2.6.12 kernels:

skb_over_panic: text:ffffffffa01ea1c3 len:31056 put:30768
head:ffff88011bd81800 data:ffff88011bd81800 tail:0x7950
end:0x440 dev:<NULL>
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:129!
[...]
Call Trace:
<IRQ>
[<ffffffff8144fb1c>] skb_put+0x5c/0x70
[<ffffffffa01ea1c3>] sctp_addto_chunk+0x63/0xd0 [sctp]
[<ffffffffa01eadaf>] sctp_process_asconf+0x1af/0x540 [sctp]
[<ffffffff8152d025>] ? _read_unlock_bh+0x15/0x20
[<ffffffffa01e0038>] sctp_sf_do_asconf+0x168/0x240 [sctp]
[<ffffffffa01e3751>] sctp_do_sm+0x71/0x1210 [sctp]
[<ffffffff8147645d>] ? fib_rules_lookup+0xad/0xf0
[<ffffffffa01e6b22>] ? sctp_cmp_addr_exact+0x32/0x40 [sctp]
[<ffffffffa01e8393>] sctp_assoc_bh_rcv+0xd3/0x180 [sctp]
[<ffffffffa01ee986>] sctp_inq_push+0x56/0x80 [sctp]
[<ffffffffa01fcc42>] sctp_rcv+0x982/0xa10 [sctp]
[<ffffffffa01d5123>] ? ipt_local_in_hook+0x23/0x28 [iptable_filter]
[<ffffffff8148bdc9>] ? nf_iterate+0x69/0xb0
[<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0
[<ffffffff8148bf86>] ? nf_hook_slow+0x76/0x120
[<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0
[<ffffffff81496ded>] ip_local_deliver_finish+0xdd/0x2d0
[<ffffffff81497078>] ip_local_deliver+0x98/0xa0
[<ffffffff8149653d>] ip_rcv_finish+0x12d/0x440
[<ffffffff81496ac5>] ip_rcv+0x275/0x350
[<ffffffff8145c88b>] __netif_receive_skb+0x4ab/0x750
[<ffffffff81460588>] netif_receive_skb+0x58/0x60

This can be triggered e.g., through a simple scripted nmap
connection scan injecting the chunk after the handshake, for
example, ...

-------------- INIT[ASCONF; ASCONF_ACK] ------------->
<----------- INIT-ACK[ASCONF; ASCONF_ACK] ------------
-------------------- COOKIE-ECHO -------------------->
<-------------------- COOKIE-ACK ---------------------
------------------ ASCONF; UNKNOWN ------------------>

... where ASCONF chunk of length 280 contains 2 parameters ...

1) Add IP address parameter (param length: 16)
2) Add/del IP address parameter (param length: 255)

... followed by an UNKNOWN chunk of e.g. 4 bytes. Here, the
Address Parameter in the ASCONF chunk is even missing, too.
This is just an example and similarly-crafted ASCONF chunks
could be used just as well.

The ASCONF chunk passes through sctp_verify_asconf() as all
parameters passed sanity checks, and after walking, we ended
up successfully at the chunk end boundary, and thus may invoke
sctp_process_asconf(). Parameter walking is done with
WORD_ROUND() to take padding into account.

In sctp_process_asconf()'s TLV processing, we may fail in
sctp_process_asconf_param() e.g., due to removal of the IP
address that is also the source address of the packet containing
the ASCONF chunk, and thus we need to add all TLVs after the
failure to our ASCONF response to remote via helper function
sctp_add_asconf_response(), which basically invokes a
sctp_addto_chunk() adding the error parameters to the given
skb.

When walking to the next parameter this time, we proceed
with ...

length = ntohs(asconf_param->param_hdr.length);
asconf_param = (void *)asconf_param + length;

... instead of the WORD_ROUND()'ed length, thus resulting here
in an off-by-one that leads to reading the follow-up garbage
parameter length of 12336, and thus throwing an skb_over_panic
for the reply when trying to sctp_addto_chunk() next time,
which implicitly calls the skb_put() with that length.

Fix it by using sctp_walk_params() [ which is also used in
INIT parameter processing ] macro in the verification *and*
in ASCONF processing: it will make sure we don't spill over,
that we walk parameters WORD_ROUND()'ed. Moreover, we're being
more defensive and guard against unknown parameter types and
missized addresses.

Joint work with Vlad Yasevich.

Fixes: b896b82be4ae ("[SCTP] ADDIP: Support for processing incoming ASCONF_ACK chunks.")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

ktime: add ktime_after and ktime_before helper

Add two minimal helper functions analogous to time_before() and
time_after() that will later on both be needed by SCTP code.

Signed-off-by: Daniel Bor

ktime: add ktime_after and ktime_before helper

Add two minimal helper functions analogous to time_before() and
time_after() that will later on both be needed by SCTP code.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: sctp: cache auth_enable per endpoint

Currently, it is possible to create an SCTP socket, then switch
auth_enable via sysctl setting to 1 and crash the system on connect:

Oops[#1]:
CPU: 0 PID:

net: sctp: cache auth_enable per endpoint

Currently, it is possible to create an SCTP socket, then switch
auth_enable via sysctl setting to 1 and crash the system on connect:

Oops[#1]:
CPU: 0 PID: 0 Comm: swapper Not tainted 3.14.1-mipsgit-20140415 #1
task: ffffffff8056ce80 ti: ffffffff8055c000 task.ti: ffffffff8055c000
[...]
Call Trace:
[<ffffffff8043c4e8>] sctp_auth_asoc_set_default_hmac+0x68/0x80
[<ffffffff8042b300>] sctp_process_init+0x5e0/0x8a4
[<ffffffff8042188c>] sctp_sf_do_5_1B_init+0x234/0x34c
[<ffffffff804228c8>] sctp_do_sm+0xb4/0x1e8
[<ffffffff80425a08>] sctp_endpoint_bh_rcv+0x1c4/0x214
[<ffffffff8043af68>] sctp_rcv+0x588/0x630
[<ffffffff8043e8e8>] sctp6_rcv+0x10/0x24
[<ffffffff803acb50>] ip6_input+0x2c0/0x440
[<ffffffff8030fc00>] __netif_receive_skb_core+0x4a8/0x564
[<ffffffff80310650>] process_backlog+0xb4/0x18c
[<ffffffff80313cbc>] net_rx_action+0x12c/0x210
[<ffffffff80034254>] __do_softirq+0x17c/0x2ac
[<ffffffff800345e0>] irq_exit+0x54/0xb0
[<ffffffff800075a4>] ret_from_irq+0x0/0x4
[<ffffffff800090ec>] rm7k_wait_irqoff+0x24/0x48
[<ffffffff8005e388>] cpu_startup_entry+0xc0/0x148
[<ffffffff805a88b0>] start_kernel+0x37c/0x398
Code: dd0900b8 000330f8 0126302d <dcc60000> 50c0fff1 0047182a a48306a0
03e00008 00000000
---[ end trace b530b0551467f2fd ]---
Kernel panic - not syncing: Fatal exception in interrupt

What happens while auth_enable=0 in that case is, that
ep->auth_hmacs is initialized to NULL in sctp_auth_init_hmacs()
when endpoint is being created.

After that point, if an admin switches over to auth_enable=1,
the machine can crash due to NULL pointer dereference during
reception of an INIT chunk. When we enter sctp_process_init()
via sctp_sf_do_5_1B_init() in order to respond to an INIT chunk,
the INIT verification succeeds and while we walk and process
all INIT params via sctp_process_param() we find that
net->sctp.auth_enable is set, therefore do not fall through,
but invoke sctp_auth_asoc_set_default_hmac() instead, and thus,
dereference what we have set to NULL during endpoint
initialization phase.

The fix is to make auth_enable immutable by caching its value
during endpoint initialization, so that its original value is
being carried along until destruction. The bug seems to originate
from the very first days.

Fix in joint work with Daniel Borkmann.

Reported-by: Joshua Kinard <kumba@gentoo.org>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Tested-by: Joshua Kinard <kumba@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: sctp: fix skb leakage in COOKIE ECHO path of chunk->auth_chunk

While working on ec0223ec48a9 ("net: sctp: fix sctp_sf_do_5_1D_ce to
verify if we/peer is AUTH capable"), we noticed that there's

net: sctp: fix skb leakage in COOKIE ECHO path of chunk->auth_chunk

While working on ec0223ec48a9 ("net: sctp: fix sctp_sf_do_5_1D_ce to
verify if we/peer is AUTH capable"), we noticed that there's a skb
memory leakage in the error path.

Running the same reproducer as in ec0223ec48a9 and by unconditionally
jumping to the error label (to simulate an error condition) in
sctp_sf_do_5_1D_ce() receive path lets kmemleak detector bark about
the unfreed chunk->auth_chunk skb clone:

Unreferenced object 0xffff8800b8f3a000 (size 256):
comm "softirq", pid 0, jiffies 4294769856 (age 110.757s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
89 ab 75 5e d4 01 58 13 00 00 00 00 00 00 00 00 ..u^..X.........
backtrace:
[<ffffffff816660be>] kmemleak_alloc+0x4e/0xb0
[<ffffffff8119f328>] kmem_cache_alloc+0xc8/0x210
[<ffffffff81566929>] skb_clone+0x49/0xb0
[<ffffffffa0467459>] sctp_endpoint_bh_rcv+0x1d9/0x230 [sctp]
[<ffffffffa046fdbc>] sctp_inq_push+0x4c/0x70 [sctp]
[<ffffffffa047e8de>] sctp_rcv+0x82e/0x9a0 [sctp]
[<ffffffff815abd38>] ip_local_deliver_finish+0xa8/0x210
[<ffffffff815a64af>] nf_reinject+0xbf/0x180
[<ffffffffa04b4762>] nfqnl_recv_verdict+0x1d2/0x2b0 [nfnetlink_queue]
[<ffffffffa04aa40b>] nfnetlink_rcv_msg+0x14b/0x250 [nfnetlink]
[<ffffffff815a3269>] netlink_rcv_skb+0xa9/0xc0
[<ffffffffa04aa7cf>] nfnetlink_rcv+0x23f/0x408 [nfnetlink]
[<ffffffff815a2bd8>] netlink_unicast+0x168/0x250
[<ffffffff815a2fa1>] netlink_sendmsg+0x2e1/0x3f0
[<ffffffff8155cc6b>] sock_sendmsg+0x8b/0xc0
[<ffffffff8155d449>] ___sys_sendmsg+0x369/0x380

What happens is that commit bbd0d59809f9 clones the skb containing
the AUTH chunk in sctp_endpoint_bh_rcv() when having the edge case
that an endpoint requires COOKIE-ECHO chunks to be authenticated:

---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ---------->
<------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] ---------
------------------ AUTH; COOKIE-ECHO ---------------->
<-------------------- COOKIE-ACK ---------------------

When we enter sctp_sf_do_5_1D_ce() and before we actually get to
the point where we process (and subsequently free) a non-NULL
chunk->auth_chunk, we could hit the "goto nomem_init" path from
an error condition and thus leave the cloned skb around w/o
freeing it.

The fix is to centrally free such clones in sctp_chunk_destroy()
handler that is invoked from sctp_chunk_free() after all refs have
dropped; and also move both kfree_skb(chunk->auth_chunk) there,
so that chunk->auth_chunk is either NULL (since sctp_chunkify()
allocs new chunks through kmem_cache_zalloc()) or non-NULL with
a valid skb pointer. chunk->skb and chunk->auth_chunk are the
only skbs in the sctp_chunk structure that need to be handeled.

While at it, we should use consume_skb() for both. It is the same
as dev_kfree_skb() but more appropriately named as we are not
a device but a protocol. Also, this effectively replaces the
kfree_skb() from both invocations into consume_skb(). Functions
are the same only that kfree_skb() assumes that the frame was
being dropped after a failure (e.g. for tools like drop monitor),
usage of consume_skb() seems more appropriate in function
sctp_chunk_destroy() though.

Fixes: bbd0d59809f9 ("[SCTP]: Implement the receive and verification of AUTH chunk")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Vlad Yasevich <yasevich@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: make sctp_addto_chunk_fixed local

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.ne

sctp: make sctp_addto_chunk_fixed local

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: fix checkpatch errors with indent

fix checkpatch errors below:
ERROR: switch and case should be at the same inden
ERROR: code indent should use tabs where possible

Acked-by: Neil Horman <nhor

sctp: fix checkpatch errors with indent

fix checkpatch errors below:
ERROR: switch and case should be at the same inden
ERROR: code indent should use tabs where possible

Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: fix checkpatch errors with (foo*)|foo * bar|foo* bar

fix checkpatch errors below:
ERROR: "(foo*)" should be "(foo *)"
ERROR: "foo * bar" should be "foo *bar"
ERROR: "foo* bar" should be "foo *

sctp: fix checkpatch errors with (foo*)|foo * bar|foo* bar

fix checkpatch errors below:
ERROR: "(foo*)" should be "(foo *)"
ERROR: "foo * bar" should be "foo *bar"
ERROR: "foo* bar" should be "foo *bar"

Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: fix checkpatch errors with space required or prohibited

fix checkpatch errors while the space is required or prohibited
to the "=,()++..."

Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed

sctp: fix checkpatch errors with space required or prohibited

fix checkpatch errors while the space is required or prohibited
to the "=,()++..."

Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

sctp: Fix FSF address in file headers

Several files refer to an old address for the Free Software Foundation
in the file header comment. Resolve by replacing the address with
the URL <http://www.gn

sctp: Fix FSF address in file headers

Several files refer to an old address for the Free Software Foundation
in the file header comment. Resolve by replacing the address with
the URL <http://www.gnu.org/licenses/> so that we do not have to keep
updating the header comments anytime the address changes.

CC: Vlad Yasevich <vyasevich@gmail.com>
CC: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...