1607 Commits

Author SHA1 Message Date
Maciej Kwiecien
a184a9d601 sctp: don't compare hb_timer expire date before starting it
[ Upstream commit d1f20c03f48102e52eb98b8651d129b83134cae4 ]

hb_timer might not start at all for a particular transport because its
start is conditional. In a result a node is not sending heartbeats.

Function sctp_transport_reset_hb_timer has two roles:
    - initial start of hb_timer for a given transport,
    - update expire date of hb_timer for a given transport.
The function is optimized to update timer's expire only if it is before
a new calculated one but this comparison is invalid for a timer which
has not yet started. Such a timer has expire == 0 and if a new expire
value is bigger than (MAX_JIFFIES / 2 + 2) then "time_before" macro will
fail and timer will not start resulting in no heartbeat packets send by
the node.

This was found when association was initialized within first 5 mins
after system boot due to jiffies init value which is near to MAX_JIFFIES.

Test kernel version: 4.9.154 (ARCH=arm)
hb_timer.expire = 0;                //initialized, not started timer
new_expire = MAX_JIFFIES / 2 + 2;   //or more
time_before(hb_timer.expire, new_expire) == false

Fixes: ba6f5e33bdbb ("sctp: avoid refreshing heartbeat timer too often")
Reported-by: Marcin Stojek <marcin.stojek@nokia.com>
Tested-by: Marcin Stojek <marcin.stojek@nokia.com>
Signed-off-by: Maciej Kwiecien <maciej.kwiecien@nokia.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05 15:37:58 +01:00
Eric Dumazet
4fa6002a34 inet: stop leaking jiffies on the wire
[ Upstream commit a904a0693c189691eeee64f6c6b188bd7dc244e9 ]

Historically linux tried to stick to RFC 791, 1122, 2003
for IPv4 ID field generation.

RFC 6864 made clear that no matter how hard we try,
we can not ensure unicity of IP ID within maximum
lifetime for all datagrams with a given source
address/destination address/protocol tuple.

Linux uses a per socket inet generator (inet_id), initialized
at connection startup with a XOR of 'jiffies' and other
fields that appear clear on the wire.

Thiemo Nagel pointed that this strategy is a privacy
concern as this provides 16 bits of entropy to fingerprint
devices.

Let's switch to a random starting point, this is just as
good as far as RFC 6864 is concerned and does not leak
anything critical.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Thiemo Nagel <tnagel@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10 11:25:37 +01:00
Eric Dumazet
0d50fc2bb4 net: use skb_queue_empty_lockless() in busy poll contexts
[ Upstream commit 3f926af3f4d688e2e11e7f8ed04e277a14d4d4a4 ]

Busy polling usually runs without locks.
Let's use skb_queue_empty_lockless() instead of skb_queue_empty()

Also uses READ_ONCE() in __skb_try_recv_datagram() to address
a similar potential problem.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10 11:25:35 +01:00
Eric Dumazet
8e7bea4359 net: use skb_queue_empty_lockless() in poll() handlers
[ Upstream commit 3ef7cf57c72f32f61e97f8fa401bc39ea1f1a5d4 ]

Many poll() handlers are lockless. Using skb_queue_empty_lockless()
instead of skb_queue_empty() is more appropriate.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10 11:25:34 +01:00
Xin Long
7c3c0d5112 sctp: not bind the socket in sctp_connect
commit 9b6c08878e23adb7cc84bdca94d8a944b03f099e upstream.

Now when sctp_connect() is called with a wrong sa_family, it binds
to a port but doesn't set bp->port, then sctp_get_af_specific will
return NULL and sctp_connect() returns -EINVAL.

Then if sctp_bind() is called to bind to another port, the last
port it has bound will leak due to bp->port is NULL by then.

sctp_connect() doesn't need to bind ports, as later __sctp_connect
will do it if bp->port is NULL. So remove it from sctp_connect().
While at it, remove the unnecessary sockaddr.sa_family len check
as it's already done in sctp_inet_connect.

Fixes: 644fbdeacf1d ("sctp: fix the issue that flags are ignored when using kernel_connect")
Reported-by: syzbot+079bf326b38072f849d9@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-06 12:43:39 +01:00
Xin Long
8afb9f5344 sctp: fix the issue that flags are ignored when using kernel_connect
commit 644fbdeacf1d3edd366e44b8ba214de9d1dd66a9 upstream.

Now sctp uses inet_dgram_connect as its proto_ops .connect, and the flags
param can't be passed into its proto .connect where this flags is really
needed.

sctp works around it by getting flags from socket file in __sctp_connect.
It works for connecting from userspace, as inherently the user sock has
socket file and it passes f_flags as the flags param into the proto_ops
.connect.

However, the sock created by sock_create_kern doesn't have a socket file,
and it passes the flags (like O_NONBLOCK) by using the flags param in
kernel_connect, which calls proto_ops .connect later.

So to fix it, this patch defines a new proto_ops .connect for sctp,
sctp_inet_connect, which calls __sctp_connect() directly with this
flags param. After this, the sctp's proto .connect can be removed.

Note that sctp_inet_connect doesn't need to do some checks that are not
needed for sctp, which makes thing better than with inet_dgram_connect.

Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-06 12:43:39 +01:00
Xin Long
dce4350a1d sctp: change sctp_prot .no_autobind with true
[ Upstream commit 63dfb7938b13fa2c2fbcb45f34d065769eb09414 ]

syzbot reported a memory leak:

  BUG: memory leak, unreferenced object 0xffff888120b3d380 (size 64):
  backtrace:

    [...] slab_alloc mm/slab.c:3319 [inline]
    [...] kmem_cache_alloc+0x13f/0x2c0 mm/slab.c:3483
    [...] sctp_bucket_create net/sctp/socket.c:8523 [inline]
    [...] sctp_get_port_local+0x189/0x5a0 net/sctp/socket.c:8270
    [...] sctp_do_bind+0xcc/0x200 net/sctp/socket.c:402
    [...] sctp_bindx_add+0x4b/0xd0 net/sctp/socket.c:497
    [...] sctp_setsockopt_bindx+0x156/0x1b0 net/sctp/socket.c:1022
    [...] sctp_setsockopt net/sctp/socket.c:4641 [inline]
    [...] sctp_setsockopt+0xaea/0x2dc0 net/sctp/socket.c:4611
    [...] sock_common_setsockopt+0x38/0x50 net/core/sock.c:3147
    [...] __sys_setsockopt+0x10f/0x220 net/socket.c:2084
    [...] __do_sys_setsockopt net/socket.c:2100 [inline]

It was caused by when sending msgs without binding a port, in the path:
inet_sendmsg() -> inet_send_prepare() -> inet_autobind() ->
.get_port/sctp_get_port(), sp->bind_hash will be set while bp->port is
not. Later when binding another port by sctp_setsockopt_bindx(), a new
bucket will be created as bp->port is not set.

sctp's autobind is supposed to call sctp_autobind() where it does all
things including setting bp->port. Since sctp_autobind() is called in
sctp_sendmsg() if the sk is not yet bound, it should have skipped the
auto bind.

THis patch is to avoid calling inet_autobind() in inet_send_prepare()
by changing sctp_prot .no_autobind with true, also remove the unused
.get_port.

Reported-by: syzbot+d44f7bbebdea49dbc84a@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-29 09:17:03 +01:00
Xin Long
701234af94 sctp: use transport pf_retrans in sctp_do_8_2_transport_strike
[ Upstream commit 10eb56c582c557c629271f1ee31e15e7a9b2558b ]

Transport should use its own pf_retrans to do the error_count
check, instead of asoc's. Otherwise, it's meaningless to make
pf_retrans per transport.

Fixes: 5aa93bcf66f4 ("sctp: Implement quick failover draft from tsvwg")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-19 09:08:01 +02:00
Christophe JAILLET
e90daafad0 sctp: Fix the link time qualifier of 'sctp_ctrlsock_exit()'
[ Upstream commit b456d72412ca8797234449c25815e82f4e1426c0 ]

The '.exit' functions from 'pernet_operations' structure should be marked
as __net_exit, not __net_init.

Fixes: 8e2d61e0aed2 ("sctp: fix race on protocol/netns initialization")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-19 09:08:01 +02:00
Xin Long
382d899183 sctp: fix the transport error_count check
[ Upstream commit a1794de8b92ea6bc2037f445b296814ac826693e ]

As the annotation says in sctp_do_8_2_transport_strike():

  "If the transport error count is greater than the pf_retrans
   threshold, and less than pathmaxrtx ..."

It should be transport->error_count checked with pathmaxrxt,
instead of asoc->pf_retrans.

Fixes: 5aa93bcf66f4 ("sctp: Implement quick failover draft from tsvwg")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-25 10:50:27 +02:00
Xin Long
ee598530be sctp: change to hold sk after auth shkey is created successfully
[ Upstream commit 25bff6d5478b2a02368097015b7d8eb727c87e16 ]

Now in sctp_endpoint_init(), it holds the sk then creates auth
shkey. But when the creation fails, it doesn't release the sk,
which causes a sk defcnf leak,

Here to fix it by only holding the sk when auth shkey is created
successfully.

Fixes: a29a5bd4f5c3 ("[SCTP]: Implement SCTP-AUTH initializations.")
Reported-by: syzbot+afabda3890cc2f765041@syzkaller.appspotmail.com
Reported-by: syzbot+276ca1c77a19977c0130@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03 13:16:02 +02:00
Neil Horman
c4964bfaf4 sctp: Free cookie before we memdup a new one
[ Upstream commit ce950f1050cece5e406a5cde723c69bba60e1b26 ]

Based on comments from Xin, even after fixes for our recent syzbot
report of cookie memory leaks, its possible to get a resend of an INIT
chunk which would lead to us leaking cookie memory.

To ensure that we don't leak cookie memory, free any previously
allocated cookie first.

Change notes
v1->v2
update subsystem tag in subject (davem)
repeat kfree check for peer_random and peer_hmacs (xin)

v2->v3
net->sctp
also free peer_chunks

v3->v4
fix subject tags

v4->v5
remove cut line

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: syzbot+f7e9153b037eac9b1df8@syzkaller.appspotmail.com
CC: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
CC: Xin Long <lucien.xin@gmail.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: netdev@vger.kernel.org
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-22 08:16:15 +02:00
Neil Horman
2cdb66cccf Fix memory leak in sctp_process_init
[ Upstream commit 0a8dd9f67cd0da7dc284f48b032ce00db1a68791 ]

syzbot found the following leak in sctp_process_init
BUG: memory leak
unreferenced object 0xffff88810ef68400 (size 1024):
  comm "syz-executor273", pid 7046, jiffies 4294945598 (age 28.770s)
  hex dump (first 32 bytes):
    1d de 28 8d de 0b 1b e3 b5 c2 f9 68 fd 1a 97 25  ..(........h...%
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000a02cebbd>] kmemleak_alloc_recursive include/linux/kmemleak.h:55
[inline]
    [<00000000a02cebbd>] slab_post_alloc_hook mm/slab.h:439 [inline]
    [<00000000a02cebbd>] slab_alloc mm/slab.c:3326 [inline]
    [<00000000a02cebbd>] __do_kmalloc mm/slab.c:3658 [inline]
    [<00000000a02cebbd>] __kmalloc_track_caller+0x15d/0x2c0 mm/slab.c:3675
    [<000000009e6245e6>] kmemdup+0x27/0x60 mm/util.c:119
    [<00000000dfdc5d2d>] kmemdup include/linux/string.h:432 [inline]
    [<00000000dfdc5d2d>] sctp_process_init+0xa7e/0xc20
net/sctp/sm_make_chunk.c:2437
    [<00000000b58b62f8>] sctp_cmd_process_init net/sctp/sm_sideeffect.c:682
[inline]
    [<00000000b58b62f8>] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1384
[inline]
    [<00000000b58b62f8>] sctp_side_effects net/sctp/sm_sideeffect.c:1194
[inline]
    [<00000000b58b62f8>] sctp_do_sm+0xbdc/0x1d60 net/sctp/sm_sideeffect.c:1165
    [<0000000044e11f96>] sctp_assoc_bh_rcv+0x13c/0x200
net/sctp/associola.c:1074
    [<00000000ec43804d>] sctp_inq_push+0x7f/0xb0 net/sctp/inqueue.c:95
    [<00000000726aa954>] sctp_backlog_rcv+0x5e/0x2a0 net/sctp/input.c:354
    [<00000000d9e249a8>] sk_backlog_rcv include/net/sock.h:950 [inline]
    [<00000000d9e249a8>] __release_sock+0xab/0x110 net/core/sock.c:2418
    [<00000000acae44fa>] release_sock+0x37/0xd0 net/core/sock.c:2934
    [<00000000963cc9ae>] sctp_sendmsg+0x2c0/0x990 net/sctp/socket.c:2122
    [<00000000a7fc7565>] inet_sendmsg+0x64/0x120 net/ipv4/af_inet.c:802
    [<00000000b732cbd3>] sock_sendmsg_nosec net/socket.c:652 [inline]
    [<00000000b732cbd3>] sock_sendmsg+0x54/0x70 net/socket.c:671
    [<00000000274c57ab>] ___sys_sendmsg+0x393/0x3c0 net/socket.c:2292
    [<000000008252aedb>] __sys_sendmsg+0x80/0xf0 net/socket.c:2330
    [<00000000f7bf23d1>] __do_sys_sendmsg net/socket.c:2339 [inline]
    [<00000000f7bf23d1>] __se_sys_sendmsg net/socket.c:2337 [inline]
    [<00000000f7bf23d1>] __x64_sys_sendmsg+0x23/0x30 net/socket.c:2337
    [<00000000a8b4131f>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:3

The problem was that the peer.cookie value points to an skb allocated
area on the first pass through this function, at which point it is
overwritten with a heap allocated value, but in certain cases, where a
COOKIE_ECHO chunk is included in the packet, a second pass through
sctp_process_init is made, where the cookie value is re-allocated,
leaking the first allocation.

Fix is to always allocate the cookie value, and free it when we are done
using it.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: syzbot+f7e9153b037eac9b1df8@syzkaller.appspotmail.com
CC: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: netdev@vger.kernel.org
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-11 12:21:44 +02:00
Xin Long
a5d0034533 sctp: avoid running the sctp state machine recursively
[ Upstream commit fbd019737d71e405f86549fd738f81e2ff3dd073 ]

Ying triggered a call trace when doing an asconf testing:

  BUG: scheduling while atomic: swapper/12/0/0x10000100
  Call Trace:
   <IRQ>  [<ffffffffa4375904>] dump_stack+0x19/0x1b
   [<ffffffffa436fcaf>] __schedule_bug+0x64/0x72
   [<ffffffffa437b93a>] __schedule+0x9ba/0xa00
   [<ffffffffa3cd5326>] __cond_resched+0x26/0x30
   [<ffffffffa437bc4a>] _cond_resched+0x3a/0x50
   [<ffffffffa3e22be8>] kmem_cache_alloc_node+0x38/0x200
   [<ffffffffa423512d>] __alloc_skb+0x5d/0x2d0
   [<ffffffffc0995320>] sctp_packet_transmit+0x610/0xa20 [sctp]
   [<ffffffffc098510e>] sctp_outq_flush+0x2ce/0xc00 [sctp]
   [<ffffffffc098646c>] sctp_outq_uncork+0x1c/0x20 [sctp]
   [<ffffffffc0977338>] sctp_cmd_interpreter.isra.22+0xc8/0x1460 [sctp]
   [<ffffffffc0976ad1>] sctp_do_sm+0xe1/0x350 [sctp]
   [<ffffffffc099443d>] sctp_primitive_ASCONF+0x3d/0x50 [sctp]
   [<ffffffffc0977384>] sctp_cmd_interpreter.isra.22+0x114/0x1460 [sctp]
   [<ffffffffc0976ad1>] sctp_do_sm+0xe1/0x350 [sctp]
   [<ffffffffc097b3a4>] sctp_assoc_bh_rcv+0xf4/0x1b0 [sctp]
   [<ffffffffc09840f1>] sctp_inq_push+0x51/0x70 [sctp]
   [<ffffffffc099732b>] sctp_rcv+0xa8b/0xbd0 [sctp]

As it shows, the first sctp_do_sm() running under atomic context (NET_RX
softirq) invoked sctp_primitive_ASCONF() that uses GFP_KERNEL flag later,
and this flag is supposed to be used in non-atomic context only. Besides,
sctp_do_sm() was called recursively, which is not expected.

Vlad tried to fix this recursive call in Commit c0786693404c ("sctp: Fix
oops when sending queued ASCONF chunks") by introducing a new command
SCTP_CMD_SEND_NEXT_ASCONF. But it didn't work as this command is still
used in the first sctp_do_sm() call, and sctp_primitive_ASCONF() will
be called in this command again.

To avoid calling sctp_do_sm() recursively, we send the next queued ASCONF
not by sctp_primitive_ASCONF(), but by sctp_sf_do_prm_asconf() in the 1st
sctp_do_sm() directly.

Reported-by: Ying Xu <yinxu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-08 07:20:44 +02:00
Xin Long
a7bc830b76 sctp: initialize _pad of sockaddr_in before copying to user memory
[ Upstream commit 09279e615c81ce55e04835970601ae286e3facbe ]

Syzbot report a kernel-infoleak:

  BUG: KMSAN: kernel-infoleak in _copy_to_user+0x16b/0x1f0 lib/usercopy.c:32
  Call Trace:
    _copy_to_user+0x16b/0x1f0 lib/usercopy.c:32
    copy_to_user include/linux/uaccess.h:174 [inline]
    sctp_getsockopt_peer_addrs net/sctp/socket.c:5911 [inline]
    sctp_getsockopt+0x1668e/0x17f70 net/sctp/socket.c:7562
    ...
  Uninit was stored to memory at:
    sctp_transport_init net/sctp/transport.c:61 [inline]
    sctp_transport_new+0x16d/0x9a0 net/sctp/transport.c:115
    sctp_assoc_add_peer+0x532/0x1f70 net/sctp/associola.c:637
    sctp_process_param net/sctp/sm_make_chunk.c:2548 [inline]
    sctp_process_init+0x1a1b/0x3ed0 net/sctp/sm_make_chunk.c:2361
    ...
  Bytes 8-15 of 16 are uninitialized

It was caused by that th _pad field (the 8-15 bytes) of a v4 addr (saved in
struct sockaddr_in) wasn't initialized, but directly copied to user memory
in sctp_getsockopt_peer_addrs().

So fix it by calling memset(addr->v4.sin_zero, 0, 8) to initialize _pad of
sockaddr_in before copying it to user memory in sctp_v4_addr_to_user(), as
sctp_v6_addr_to_user() does.

Reported-by: syzbot+86b5c7c236a22616a72f@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Tested-by: Alexander Potapenko <glider@google.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-17 08:37:47 +02:00
Konstantin Khlebnikov
3daca16bdd inet_diag: fix reporting cgroup classid and fallback to priority
[ Upstream commit 1ec17dbd90f8b638f41ee650558609c1af63dfa0 ]

Field idiag_ext in struct inet_diag_req_v2 used as bitmap of requested
extensions has only 8 bits. Thus extensions starting from DCTCPINFO
cannot be requested directly. Some of them included into response
unconditionally or hook into some of lower 8 bits.

Extension INET_DIAG_CLASS_ID has not way to request from the beginning.

This patch bundle it with INET_DIAG_TCLASS (ipv6 tos), fixes space
reservation, and documents behavior for other extensions.

Also this patch adds fallback to reporting socket priority. This filed
is more widely used for traffic classification because ipv4 sockets
automatically maps TOS to priority and default qdisc pfifo_fast knows
about that. But priority could be changed via setsockopt SO_PRIORITY so
INET_DIAG_TOS isn't enough for predicting class.

Also cgroup2 obsoletes net_cls classid (it always zero), but we cannot
reuse this field for reporting cgroup2 id because it is 64-bit (ino+gen).

So, after this patch INET_DIAG_CLASS_ID will report socket priority
for most common setup when net_cls isn't set and/or cgroup2 in use.

Fixes: 0888e372c37f ("net: inet: diag: expose sockets cgroup classid")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-27 10:08:07 +01:00
Xin Long
77278f05f0 sctp: call gso_reset_checksum when computing checksum in sctp_gso_segment
[ Upstream commit fc228abc2347e106a44c0e9b29ab70b712c4ca51 ]

Jianlin reported a panic when running sctp gso over gre over vlan device:

  [   84.772930] RIP: 0010:do_csum+0x6d/0x170
  [   84.790605] Call Trace:
  [   84.791054]  csum_partial+0xd/0x20
  [   84.791657]  gre_gso_segment+0x2c3/0x390
  [   84.792364]  inet_gso_segment+0x161/0x3e0
  [   84.793071]  skb_mac_gso_segment+0xb8/0x120
  [   84.793846]  __skb_gso_segment+0x7e/0x180
  [   84.794581]  validate_xmit_skb+0x141/0x2e0
  [   84.795297]  __dev_queue_xmit+0x258/0x8f0
  [   84.795949]  ? eth_header+0x26/0xc0
  [   84.796581]  ip_finish_output2+0x196/0x430
  [   84.797295]  ? skb_gso_validate_network_len+0x11/0x80
  [   84.798183]  ? ip_finish_output+0x169/0x270
  [   84.798875]  ip_output+0x6c/0xe0
  [   84.799413]  ? ip_append_data.part.50+0xc0/0xc0
  [   84.800145]  iptunnel_xmit+0x144/0x1c0
  [   84.800814]  ip_tunnel_xmit+0x62d/0x930 [ip_tunnel]
  [   84.801699]  gre_tap_xmit+0xac/0xf0 [ip_gre]
  [   84.802395]  dev_hard_start_xmit+0xa5/0x210
  [   84.803086]  sch_direct_xmit+0x14f/0x340
  [   84.803733]  __dev_queue_xmit+0x799/0x8f0
  [   84.804472]  ip_finish_output2+0x2e0/0x430
  [   84.805255]  ? skb_gso_validate_network_len+0x11/0x80
  [   84.806154]  ip_output+0x6c/0xe0
  [   84.806721]  ? ip_append_data.part.50+0xc0/0xc0
  [   84.807516]  sctp_packet_transmit+0x716/0xa10 [sctp]
  [   84.808337]  sctp_outq_flush+0xd7/0x880 [sctp]

It was caused by SKB_GSO_CB(skb)->csum_start not set in sctp_gso_segment.
sctp_gso_segment() calls skb_segment() with 'feature | NETIF_F_HW_CSUM',
which causes SKB_GSO_CB(skb)->csum_start not to be set in skb_segment().

For TCP/UDP, when feature supports HW_CSUM, CHECKSUM_PARTIAL will be set
and gso_reset_checksum will be called to set SKB_GSO_CB(skb)->csum_start.

So SCTP should do the same as TCP/UDP, to call gso_reset_checksum() when
computing checksum in sctp_gso_segment.

Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-27 10:08:06 +01:00
Xin Long
556e554a3b sctp: improve the events for sctp stream reset
[ Upstream commit 2e6dc4d95110becfe0ff4c3d4749c33ea166e9e7 ]

This patch is to improve sctp stream reset events in 4 places:

  1. In sctp_process_strreset_outreq(), the flag should always be set with
     SCTP_STREAM_RESET_INCOMING_SSN instead of OUTGOING, as receiver's in
     stream is reset here.
  2. In sctp_process_strreset_outreq(), move up SCTP_STRRESET_ERR_WRONG_SSN
     check, as the reset has to succeed after reconf_timer stops for the
     in stream reset request retransmission.
  3. In sctp_process_strreset_inreq(), no event should be sent, as no in
     or out stream is reset here.
  4. In sctp_process_strreset_resp(), SCTP_STREAM_RESET_INCOMING_SSN or
     OUTGOING event should always be sent for stream reset requests, no
     matter it fails or succeeds to process the request.

Fixes: 810544764536 ("sctp: implement receiver-side procedures for the Outgoing SSN Reset Request Parameter")
Fixes: 16e1a91965b0 ("sctp: implement receiver-side procedures for the Incoming SSN Reset Request Parameter")
Fixes: 11ae76e67a17 ("sctp: implement receiver-side procedures for the Reconf Response Parameter")
Reported-by: Ying Xu <yinxu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 17:31:33 +01:00
Xin Long
f97e785670 sctp: improve the events for sctp stream adding
[ Upstream commit 8220c870cb0f4eaa4e335c9645dbd9a1c461c1dd ]

This patch is to improve sctp stream adding events in 2 places:

  1. In sctp_process_strreset_addstrm_out(), move up SCTP_MAX_STREAM
     and in stream allocation failure checks, as the adding has to
     succeed after reconf_timer stops for the in stream adding
     request retransmission.

  3. In sctp_process_strreset_addstrm_in(), no event should be sent,
     as no in or out stream is added here.

Fixes: 50a41591f110 ("sctp: implement receiver-side procedures for the Add Outgoing Streams Request Parameter")
Fixes: c5c4ebb3ab87 ("sctp: implement receiver-side procedures for the Add Incoming Streams Request Parameter")
Reported-by: Ying Xu <yinxu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 17:31:33 +01:00
Xin Long
81b2fee6eb sctp: allocate sctp_sockaddr_entry with kzalloc
commit 400b8b9a2a17918f8ce00786f596f530e7f30d50 upstream.

The similar issue as fixed in Commit 4a2eb0c37b47 ("sctp: initialize
sin6_flowinfo for ipv6 addrs in sctp_inet6addr_event") also exists
in sctp_inetaddr_event, as Alexander noticed.

To fix it, allocate sctp_sockaddr_entry with kzalloc for both sctp
ipv4 and ipv6 addresses, as does in sctp_v4/6_copy_addrlist().

Reported-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reported-by: syzbot+ae0c70c0c2d40c51bb92@syzkaller.appspotmail.com
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-23 08:09:50 +01:00
Xin Long
a98fbfc3e3 sctp: initialize sin6_flowinfo for ipv6 addrs in sctp_inet6addr_event
[ Upstream commit 4a2eb0c37b4759416996fbb4c45b932500cf06d3 ]

syzbot reported a kernel-infoleak, which is caused by an uninitialized
field(sin6_flowinfo) of addr->a.v6 in sctp_inet6addr_event().
The call trace is as below:

  BUG: KMSAN: kernel-infoleak in _copy_to_user+0x19a/0x230 lib/usercopy.c:33
  CPU: 1 PID: 8164 Comm: syz-executor2 Not tainted 4.20.0-rc3+ #95
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
  Google 01/01/2011
  Call Trace:
    __dump_stack lib/dump_stack.c:77 [inline]
    dump_stack+0x32d/0x480 lib/dump_stack.c:113
    kmsan_report+0x12c/0x290 mm/kmsan/kmsan.c:683
    kmsan_internal_check_memory+0x32a/0xa50 mm/kmsan/kmsan.c:743
    kmsan_copy_to_user+0x78/0xd0 mm/kmsan/kmsan_hooks.c:634
    _copy_to_user+0x19a/0x230 lib/usercopy.c:33
    copy_to_user include/linux/uaccess.h:183 [inline]
    sctp_getsockopt_local_addrs net/sctp/socket.c:5998 [inline]
    sctp_getsockopt+0x15248/0x186f0 net/sctp/socket.c:7477
    sock_common_getsockopt+0x13f/0x180 net/core/sock.c:2937
    __sys_getsockopt+0x489/0x550 net/socket.c:1939
    __do_sys_getsockopt net/socket.c:1950 [inline]
    __se_sys_getsockopt+0xe1/0x100 net/socket.c:1947
    __x64_sys_getsockopt+0x62/0x80 net/socket.c:1947
    do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
    entry_SYSCALL_64_after_hwframe+0x63/0xe7

sin6_flowinfo is not really used by SCTP, so it will be fixed by simply
setting it to 0.

The issue exists since very beginning.
Thanks Alexander for the reproducer provided.

Reported-by: syzbot+ad5d327e6936a2e284be@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09 17:14:44 +01:00
Xin Long
862b5ab951 sctp: kfree_rcu asoc
[ Upstream commit fb6df5a6234c38a9c551559506a49a677ac6f07a ]

In sctp_hash_transport/sctp_epaddr_lookup_transport, it dereferences
a transport's asoc under rcu_read_lock while asoc is freed not after
a grace period, which leads to a use-after-free panic.

This patch fixes it by calling kfree_rcu to make asoc be freed after
a grace period.

Note that only the asoc's memory is delayed to free in the patch, it
won't cause sk to linger longer.

Thanks Neil and Marcelo to make this clear.

Fixes: 7fda702f9315 ("sctp: use new rhlist interface on sctp transport rhashtable")
Fixes: cd2b70875058 ("sctp: check duplicate node before inserting a new transport")
Reported-by: syzbot+0b05d8aa7cb185107483@syzkaller.appspotmail.com
Reported-by: syzbot+aad231d51b1923158444@syzkaller.appspotmail.com
Suggested-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17 09:28:47 +01:00
Xin Long
8376fdc999 sctp: clear the transport of some out_chunk_list chunks in sctp_assoc_rm_peer
commit df132eff463873e14e019a07f387b4d577d6d1f9 upstream.

If a transport is removed by asconf but there still are some chunks with
this transport queuing on out_chunk_list, later an use-after-free issue
will be caused when accessing this transport from these chunks in
sctp_outq_flush().

This is an old bug, we fix it by clearing the transport of these chunks
in out_chunk_list when removing a transport in sctp_assoc_rm_peer().

Reported-by: syzbot+56a40ceee5fb35932f4d@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-01 09:42:51 +01:00
Xin Long
eebe064ce4 sctp: not increase stream's incnt before sending addstrm_in request
[ Upstream commit e1e46479847e66f78f79d8c24d5169a5954b3fc2 ]

Different from processing the addstrm_out request, The receiver handles
an addstrm_in request by sending back an addstrm_out request to the
sender who will increase its stream's in and incnt later.

Now stream->incnt has been increased since it sent out the addstrm_in
request in sctp_send_add_streams(), with the wrong stream->incnt will
even cause crash when copying stream info from the old stream's in to
the new one's in sctp_process_strreset_addstrm_out().

This patch is to fix it by simply removing the stream->incnt change
from sctp_send_add_streams().

Fixes: 242bd2d519d7 ("sctp: implement sender-side procedures for Add Incoming/Outgoing Streams Request Parameter")
Reported-by: Jianwen Ji <jiji@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-23 08:19:26 +01:00
Xin Long
c7051eb3ac sctp: not allow to set asoc prsctp_enable by sockopt
[ Upstream commit cc3ccf26f0649089b3a34a2781977755ea36e72c ]

As rfc7496#section4.5 says about SCTP_PR_SUPPORTED:

   This socket option allows the enabling or disabling of the
   negotiation of PR-SCTP support for future associations.  For existing
   associations, it allows one to query whether or not PR-SCTP support
   was negotiated on a particular association.

It means only sctp sock's prsctp_enable can be set.

Note that for the limitation of SCTP_{CURRENT|ALL}_ASSOC, we will
add it when introducing SCTP_{FUTURE|CURRENT|ALL}_ASSOC for linux
sctp in another patchset.

v1->v2:
  - drop the params.assoc_id check as Neil suggested.

Fixes: 28aa4c26fce2 ("sctp: add SCTP_PR_SUPPORTED on sctp sockopt")
Reported-by: Ying Xu <yinxu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-23 08:19:26 +01:00
Marcelo Ricardo Leitner
606694e5ec sctp: fix race on sctp_id2asoc
[ Upstream commit b336decab22158937975293aea79396525f92bb3 ]

syzbot reported an use-after-free involving sctp_id2asoc.  Dmitry Vyukov
helped to root cause it and it is because of reading the asoc after it
was freed:

        CPU 1                       CPU 2
(working on socket 1)            (working on socket 2)
	                         sctp_association_destroy
sctp_id2asoc
   spin lock
     grab the asoc from idr
   spin unlock
                                   spin lock
				     remove asoc from idr
				   spin unlock
				   free(asoc)
   if asoc->base.sk != sk ... [*]

This can only be hit if trying to fetch asocs from different sockets. As
we have a single IDR for all asocs, in all SCTP sockets, their id is
unique on the system. An application can try to send stuff on an id
that matches on another socket, and the if in [*] will protect from such
usage. But it didn't consider that as that asoc may belong to another
socket, it may be freed in parallel (read: under another socket lock).

We fix it by moving the checks in [*] into the protected region. This
fixes it because the asoc cannot be freed while the lock is held.

Reported-by: syzbot+c7dd55d7aec49d48e49a@syzkaller.appspotmail.com
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-04 14:52:49 +01:00
Xin Long
d63d3995d7 sctp: update dst pmtu with the correct daddr
[ Upstream commit d7ab5cdce54da631f0c8c11e506c974536a3581e ]

When processing pmtu update from an icmp packet, it calls .update_pmtu
with sk instead of skb in sctp_transport_update_pmtu.

However for sctp, the daddr in the transport might be different from
inet_sock->inet_daddr or sk->sk_v6_daddr, which is used to update or
create the route cache. The incorrect daddr will cause a different
route cache created for the path.

So before calling .update_pmtu, inet_sock->inet_daddr/sk->sk_v6_daddr
should be updated with the daddr in the transport, and update it back
after it's done.

The issue has existed since route exceptions introduction.

Fixes: 4895c771c7f0 ("ipv4: Add FIB nexthop exceptions.")
Reported-by: ian.periam@dialogic.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18 09:16:19 +02:00
Xin Long
3c035a48e7 sctp: hold transport before accessing its asoc in sctp_transport_get_next
[ Upstream commit bab1be79a5169ac748d8292b20c86d874022d7ba ]

As Marcelo noticed, in sctp_transport_get_next, it is iterating over
transports but then also accessing the association directly, without
checking any refcnts before that, which can cause an use-after-free
Read.

So fix it by holding transport before accessing the association. With
that, sctp_transport_hold calls can be removed in the later places.

Fixes: 626d16f50f39 ("sctp: export some apis or variables for sctp_diag and reuse some for proc")
Reported-by: syzbot+fe62a0c9aa6a85c6de16@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15 09:45:25 +02:00
Marcelo Ricardo Leitner
8fb20507bc sctp: fix erroneous inc of snmp SctpFragUsrMsgs
[ Upstream commit fedb1bd3d274b33c432cb83c80c6b3cf54d509c8 ]

Currently it is incrementing SctpFragUsrMsgs when the user message size
is of the exactly same size as the maximum fragment size, which is wrong.

The fix is to increment it only when user message is bigger than the
maximum fragment size.

Fixes: bfd2e4b8734d ("sctp: refactor sctp_datamsg_from_user")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-24 13:09:03 +02:00
Xin Long
60473d7034 sctp: not allow transport timeout value less than HZ/5 for hb_timer
[ Upstream commit 1d88ba1ebb2763aa86172cd7ca05dedbeccc0d35 ]

syzbot reported a rcu_sched self-detected stall on CPU which is caused
by too small value set on rto_min with SCTP_RTOINFO sockopt. With this
value, hb_timer will get stuck there, as in its timer handler it starts
this timer again with this value, then goes to the timer handler again.

This problem is there since very beginning, and thanks to Eric for the
reproducer shared from a syzbot mail.

This patch fixes it by not allowing sctp_transport_timeout to return a
smaller value than HZ/5 for hb_timer, which is based on TCP's min rto.

Note that it doesn't fix this issue by limiting rto_min, as some users
are still using small rto and no proper value was found for it yet.

Reported-by: syzbot+3dcd59a1f907245f891f@syzkaller.appspotmail.com
Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-11 22:49:20 +02:00
Xin Long
bf2f3bae31 sctp: use the old asoc when making the cookie-ack chunk in dupcook_d
[ Upstream commit 46e16d4b956867013e0bbd7f2bad206f4aa55752 ]

When processing a duplicate cookie-echo chunk, for case 'D', sctp will
not process the param from this chunk. It means old asoc has nothing
to be updated, and the new temp asoc doesn't have the complete info.

So there's no reason to use the new asoc when creating the cookie-ack
chunk. Otherwise, like when auth is enabled for cookie-ack, the chunk
can not be set with auth, and it will definitely be dropped by peer.

This issue is there since very beginning, and we fix it by using the
old asoc instead.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-19 10:20:25 +02:00
Xin Long
4dce9afc2d sctp: remove sctp_chunk_put from fail_mark err path in sctp_ulpevent_make_rcvmsg
[ Upstream commit 6910e25de2257e2c82c7a2d126e3463cd8e50810 ]

In Commit 1f45f78f8e51 ("sctp: allow GSO frags to access the chunk too"),
it held the chunk in sctp_ulpevent_make_rcvmsg to access it safely later
in recvmsg. However, it also added sctp_chunk_put in fail_mark err path,
which is only triggered before holding the chunk.

syzbot reported a use-after-free crash happened on this err path, where
it shouldn't call sctp_chunk_put.

This patch simply removes this call.

Fixes: 1f45f78f8e51 ("sctp: allow GSO frags to access the chunk too")
Reported-by: syzbot+141d898c5f24489db4aa@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-19 10:20:25 +02:00
Xin Long
d3d4d69d9b sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr
[ Upstream commit d625329b06e46bd20baf9ee40847d11982569204 ]

Since sctp ipv6 socket also supports v4 addrs, it's possible to
compare two v4 addrs in pf v6 .cmp_addr, sctp_inet6_cmp_addr.

However after Commit 1071ec9d453a ("sctp: do not check port in
sctp_inet6_cmp_addr"), it no longer calls af1->cmp_addr, which
in this case is sctp_v4_cmp_addr, but calls __sctp_v6_cmp_addr
where it handles them as two v6 addrs. It would cause a out of
bounds crash.

syzbot found this crash when trying to bind two v4 addrs to a
v6 socket.

This patch fixes it by adding the process for two v4 addrs in
sctp_inet6_cmp_addr.

Fixes: 1071ec9d453a ("sctp: do not check port in sctp_inet6_cmp_addr")
Reported-by: syzbot+cd494c1dd681d4d93ebb@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-19 10:20:25 +02:00
Xin Long
f6c962d27d sctp: fix the issue that the cookie-ack with auth can't get processed
[ Upstream commit ce402f044e4e432c296f90eaabb8dbe8f3624391 ]

When auth is enabled for cookie-ack chunk, in sctp_inq_pop, sctp
processes auth chunk first, then continues to the next chunk in
this packet if chunk_end + chunk_hdr size < skb_tail_pointer().
Otherwise, it will go to the next packet or discard this chunk.

However, it missed the fact that cookie-ack chunk's size is equal
to chunk_hdr size, which couldn't match that check, and thus this
chunk would not get processed.

This patch fixes it by changing the check to chunk_end + chunk_hdr
size <= skb_tail_pointer().

Fixes: 26b87c788100 ("net: sctp: fix remote memory pressure from excessive queueing")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-19 10:20:25 +02:00
Xin Long
3b54f1fd87 sctp: delay the authentication for the duplicated cookie-echo chunk
[ 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 <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-19 10:20:25 +02:00
Xin Long
29b623b605 sctp: do not check port in sctp_inet6_cmp_addr
[ Upstream commit 1071ec9d453a38023579714b64a951a2fb982071 ]

pf->cmp_addr() is called before binding a v6 address to the sock. It
should not check ports, like in sctp_inet_cmp_addr.

But sctp_inet6_cmp_addr checks the addr by invoking af(6)->cmp_addr,
sctp_v6_cmp_addr where it also compares the ports.

This would cause that setsockopt(SCTP_SOCKOPT_BINDX_ADD) could bind
multiple duplicated IPv6 addresses after Commit 40b4f0fd74e4 ("sctp:
lack the check for ports in sctp_v6_cmp_addr").

This patch is to remove af->cmp_addr called in sctp_inet6_cmp_addr,
but do the proper check for both v6 addrs and v4mapped addrs.

v1->v2:
  - define __sctp_v6_cmp_addr to do the common address comparison
    used for both pf and af v6 cmp_addr.

Fixes: 40b4f0fd74e4 ("sctp: lack the check for ports in sctp_v6_cmp_addr")
Reported-by: Jianwen Ji <jiji@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:12 +02:00
Eric Dumazet
3fdd43709d sctp: sctp_sockaddr_af must check minimal addr length for AF_INET6
[ Upstream commit 81e98370293afcb58340ce8bd71af7b97f925c26 ]

Check must happen before call to ipv6_addr_v4mapped()

syzbot report was :

BUG: KMSAN: uninit-value in sctp_sockaddr_af net/sctp/socket.c:359 [inline]
BUG: KMSAN: uninit-value in sctp_do_bind+0x60f/0xdc0 net/sctp/socket.c:384
CPU: 0 PID: 3576 Comm: syzkaller968804 Not tainted 4.16.0+ #82
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
 sctp_sockaddr_af net/sctp/socket.c:359 [inline]
 sctp_do_bind+0x60f/0xdc0 net/sctp/socket.c:384
 sctp_bind+0x149/0x190 net/sctp/socket.c:332
 inet6_bind+0x1fd/0x1820 net/ipv6/af_inet6.c:293
 SYSC_bind+0x3f2/0x4b0 net/socket.c:1474
 SyS_bind+0x54/0x80 net/socket.c:1460
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x43fd49
RSP: 002b:00007ffe99df3d28 EFLAGS: 00000213 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd49
RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000213 R12: 0000000000401670
R13: 0000000000401700 R14: 0000000000000000 R15: 0000000000000000

Local variable description: ----address@SYSC_bind
Variable was created at:
 SYSC_bind+0x6f/0x4b0 net/socket.c:1461
 SyS_bind+0x54/0x80 net/socket.c:1460

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-12 12:32:24 +02:00
Eric Dumazet
3f80d01bbd sctp: do not leak kernel memory to user space
[ Upstream commit 6780db244d6b1537d139dea0ec8aad10cf9e4adb ]

syzbot produced a nice report [1]

Issue here is that a recvmmsg() managed to leak 8 bytes of kernel memory
to user space, because sin_zero (padding field) was not properly cleared.

[1]
BUG: KMSAN: uninit-value in copy_to_user include/linux/uaccess.h:184 [inline]
BUG: KMSAN: uninit-value in move_addr_to_user+0x32e/0x530 net/socket.c:227
CPU: 1 PID: 3586 Comm: syzkaller481044 Not tainted 4.16.0+ #82
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 kmsan_internal_check_memory+0x164/0x1d0 mm/kmsan/kmsan.c:1176
 kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199
 copy_to_user include/linux/uaccess.h:184 [inline]
 move_addr_to_user+0x32e/0x530 net/socket.c:227
 ___sys_recvmsg+0x4e2/0x810 net/socket.c:2211
 __sys_recvmmsg+0x54e/0xdb0 net/socket.c:2313
 SYSC_recvmmsg+0x29b/0x3e0 net/socket.c:2394
 SyS_recvmmsg+0x76/0xa0 net/socket.c:2378
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x4401c9
RSP: 002b:00007ffc56f73098 EFLAGS: 00000217 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401c9
RDX: 0000000000000001 RSI: 0000000020003ac0 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000020003bc0 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000401af0
R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000

Local variable description: ----addr@___sys_recvmsg
Variable was created at:
 ___sys_recvmsg+0xd5/0x810 net/socket.c:2172
 __sys_recvmmsg+0x54e/0xdb0 net/socket.c:2313

Bytes 8-15 of 16 are uninitialized

==================================================================
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 3586 Comm: syzkaller481044 Tainted: G    B            4.16.0+ #82
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 panic+0x39d/0x940 kernel/panic.c:183
 kmsan_report+0x238/0x240 mm/kmsan/kmsan.c:1083
 kmsan_internal_check_memory+0x164/0x1d0 mm/kmsan/kmsan.c:1176
 kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199
 copy_to_user include/linux/uaccess.h:184 [inline]
 move_addr_to_user+0x32e/0x530 net/socket.c:227
 ___sys_recvmsg+0x4e2/0x810 net/socket.c:2211
 __sys_recvmmsg+0x54e/0xdb0 net/socket.c:2313
 SYSC_recvmmsg+0x29b/0x3e0 net/socket.c:2394
 SyS_recvmmsg+0x76/0xa0 net/socket.c:2378
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc:	Vlad Yasevich <vyasevich@gmail.com>
Cc:	Neil Horman <nhorman@tuxdriver.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-12 12:32:24 +02:00
Alexey Kodanev
00ec3b0ca3 sctp: fix dst refcnt leak in sctp_v6_get_dst()
[ 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 <alexey.kodanev@oracle.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-08 22:41:15 -08:00
Xin Long
36728a6b39 sctp: do not pr_err for the duplicated node in transport rhlist
[ Upstream commit 27af86bb038d9c8b8066cd17854ddaf2ea92bce1 ]

The pr_err in sctp_hash_transport was supposed to report a sctp bug
for using rhashtable/rhlist.

The err '-EEXIST' introduced in Commit cd2b70875058 ("sctp: check
duplicate node before inserting a new transport") doesn't belong
to that case.

So just return -EEXIST back without pr_err any kmsg.

Fixes: cd2b70875058 ("sctp: check duplicate node before inserting a new transport")
Reported-by: Wei Chen <weichen@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-08 22:41:14 -08:00
Tommi Rantala
9f02a069bf sctp: fix dst refcnt leak in sctp_v4_get_dst
[ Upstream commit 4a31a6b19f9ddf498c81f5c9b089742b7472a6f8 ]

Fix dst reference count leak in sctp_v4_get_dst() introduced in commit
410f03831 ("sctp: add routing output fallback"):

When walking the address_list, successive ip_route_output_key() calls
may return the same rt->dst with the reference incremented on each call.

The code would not decrement the dst refcount when the dst pointer was
identical from the previous iteration, causing the dst refcnt leak.

Testcase:
  ip netns add TEST
  ip netns exec TEST ip link set lo up
  ip link add dummy0 type dummy
  ip link add dummy1 type dummy
  ip link add dummy2 type dummy
  ip link set dev dummy0 netns TEST
  ip link set dev dummy1 netns TEST
  ip link set dev dummy2 netns TEST
  ip netns exec TEST ip addr add 192.168.1.1/24 dev dummy0
  ip netns exec TEST ip link set dummy0 up
  ip netns exec TEST ip addr add 192.168.1.2/24 dev dummy1
  ip netns exec TEST ip link set dummy1 up
  ip netns exec TEST ip addr add 192.168.1.3/24 dev dummy2
  ip netns exec TEST ip link set dummy2 up
  ip netns exec TEST sctp_test -H 192.168.1.2 -P 20002 -h 192.168.1.1 -p 20000 -s -B 192.168.1.3
  ip netns del TEST

In 4.4 and 4.9 kernels this results to:
  [  354.179591] unregister_netdevice: waiting for lo to become free. Usage count = 1
  [  364.419674] unregister_netdevice: waiting for lo to become free. Usage count = 1
  [  374.663664] unregister_netdevice: waiting for lo to become free. Usage count = 1
  [  384.903717] unregister_netdevice: waiting for lo to become free. Usage count = 1
  [  395.143724] unregister_netdevice: waiting for lo to become free. Usage count = 1
  [  405.383645] unregister_netdevice: waiting for lo to become free. Usage count = 1
  ...

Fixes: 410f03831 ("sctp: add routing output fallback")
Fixes: 0ca50d12f ("sctp: fix src address selection if using secondary addresses")
Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-08 22:41:11 -08:00
Alexey Kodanev
1fc74a57a8 sctp: verify size of a new chunk in _sctp_make_chunk()
[ 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:<NULL>
...
[  597.976970] ------------[ cut here ]------------
[  598.033408] kernel BUG at net/core/skbuff.c:104!
[  600.314841] Call Trace:
[  600.345829]  <IRQ>
[  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 <alexey.kodanev@oracle.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leinter@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-08 22:41:10 -08:00
Marcelo Ricardo Leitner
00c840f3b5 sctp: make use of pre-calculated len
[ Upstream commit c76f97c99ae6d26d14c7f0e50e074382bfbc9f98 ]

Some sockopt handling functions were calculating the length of the
buffer to be written to userspace and then calculating it again when
actually writing the buffer, which could lead to some write not using
an up-to-date length.

This patch updates such places to just make use of the len variable.

Also, replace some sizeof(type) to sizeof(var).

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-03 10:24:37 +01:00
Marcelo Ricardo Leitner
413e58ac3d sctp: add a ceiling to optlen in some sockopts
[ Upstream commit 5960cefab9df76600a1a7d4ff592c59e14616e88 ]

Hangbin Liu reported that some sockopt calls could cause the kernel to log
a warning on memory allocation failure if the user supplied a large optlen
value. That is because some of them called memdup_user() without a ceiling
on optlen, allowing it to try to allocate really large buffers.

This patch adds a ceiling by limiting optlen to the maximum allowed that
would still make sense for these sockopt.

Reported-by: Hangbin Liu <haliu@redhat.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-03 10:24:37 +01:00
Xin Long
60f1c1f279 sctp: fix the issue that a __u16 variable may overflow in sctp_ulpq_renege
[ Upstream commit 5c468674d17056148da06218d4da5d04baf22eac ]

Now when reneging events in sctp_ulpq_renege(), the variable freed
could be increased by a __u16 value twice while freed is of __u16
type. It means freed may overflow at the second addition.

This patch is to fix it by using __u32 type for 'freed', while at
it, also to remove 'if (chunk)' check, as all renege commands are
generated in sctp_eat_data and it can't be NULL.

Reported-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-03 10:24:24 +01:00
Xin Long
7a7bcee6d7 sctp: only update outstanding_bytes for transmitted queue when doing prsctp_prune
[ Upstream commit d30fc5126efb0c33b7adf5966d3051db2c3d7721 ]

Now outstanding_bytes is only increased when appending chunks into one
packet and sending it at 1st time, while decreased when it is about to
move into retransmit queue. It means outstanding_bytes value is already
decreased for all chunks in retransmit queue.

However sctp_prsctp_prune_sent is a common function to check the chunks
in both transmitted and retransmit queue, it decrease outstanding_bytes
when moving a chunk into abandoned queue from either of them.

It could cause outstanding_bytes underflow, as it also decreases it's
value for the chunks in retransmit queue.

This patch fixes it by only updating outstanding_bytes for transmitted
queue when pruning queues for prsctp prio policy, the same fix is also
needed in sctp_check_transmitted.

Fixes: 8dbdf1f5b09c ("sctp: implement prsctp PRIO policy")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-25 11:07:57 +01:00
Xin Long
2df0d6de5e sctp: set frag_point in sctp_setsockopt_maxseg correctly
commit ecca8f88da5c4260cc2bccfefd2a24976704c366 upstream.

Now in sctp_setsockopt_maxseg user_frag or frag_point can be set with
val >= 8 and val <= SCTP_MAX_CHUNK_LEN. But both checks are incorrect.

val >= 8 means frag_point can even be less than SCTP_DEFAULT_MINSEGMENT.
Then in sctp_datamsg_from_user(), when it's value is greater than cookie
echo len and trying to bundle with cookie echo chunk, the first_len will
overflow.

The worse case is when it's value is equal as cookie echo len, first_len
becomes 0, it will go into a dead loop for fragment later on. In Hangbin
syzkaller testing env, oom was even triggered due to consecutive memory
allocation in that loop.

Besides, SCTP_MAX_CHUNK_LEN is the max size of the whole chunk, it should
deduct the data header for frag_point or user_frag check.

This patch does a proper check with SCTP_DEFAULT_MINSEGMENT subtracting
the sctphdr and datahdr, SCTP_MAX_CHUNK_LEN subtracting datahdr when
setting frag_point via sockopt. It also improves sctp_setsockopt_maxseg
codes.

Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reported-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-25 11:07:47 +01:00
Xin Long
14a4e9f6bd sctp: set sender next_tsn for the old result with ctsn_ack_point plus 1
[ Upstream commit 52a395896a051a3d5c34fba67c324f69ec5e67c6 ]

When doing asoc reset, if the sender of the response has already sent some
chunk and increased asoc->next_tsn before the duplicate request comes, the
response will use the old result with an incorrect sender next_tsn.

Better than asoc->next_tsn, asoc->ctsn_ack_point can't be changed after
the sender of the response has performed the asoc reset and before the
peer has confirmed it, and it's value is still asoc->next_tsn original
value minus 1.

This patch sets sender next_tsn for the old result with ctsn_ack_point
plus 1 when processing the duplicate request, to make sure the sender
next_tsn value peer gets will be always right.

Fixes: 692787cef651 ("sctp: implement receiver-side procedures for the SSN/TSN Reset Request Parameter")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-03 17:39:04 +01:00
Xin Long
55f3de731c sctp: avoid flushing unsent queue when doing asoc reset
[ Upstream commit 159f2a7456c6ae95c1e1a58e8b8ec65ef12d51cf ]

Now when doing asoc reset, it cleans up sacked and abandoned queues
by calling sctp_outq_free where it also cleans up unsent, retransmit
and transmitted queues.

It's safe for the sender of response, as these 3 queues are empty at
that time. But when the receiver of response is doing the reset, the
users may already enqueue some chunks into unsent during the time
waiting the response, and these chunks should not be flushed.

To void the chunks in it would be removed, it moves the queue into a
temp list, then gets it back after sctp_outq_free is done.

The patch also fixes some incorrect comments in
sctp_process_strreset_tsnreq.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-03 17:39:04 +01:00
Xin Long
d4c72a410f sctp: only allow the asoc reset when the asoc outq is empty
[ Upstream commit 5c6144a0eb5366ae07fc5059301b139338f39bbd ]

As it says in rfc6525#section5.1.4, before sending the request,

   C2:  The sender has either no outstanding TSNs or considers all
        outstanding TSNs abandoned.

Prior to this patch, it tried to consider all outstanding TSNs abandoned
by dropping all chunks in all outqs with sctp_outq_free (even including
sacked, retransmit and transmitted queues) when doing this reset, which
is too aggressive.

To make it work gently, this patch will only allow the asoc reset when
the sender has no outstanding TSNs by checking if unsent, transmitted
and retransmit are all empty with sctp_outq_is_empty before sending
and processing the request.

Fixes: 692787cef651 ("sctp: implement receiver-side procedures for the SSN/TSN Reset Request Parameter")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-03 17:39:04 +01:00