linux-stable.git/net/sctp, branch linux-4.3.y

net: sctp: prevent writes to cookie_hmac_alg from accessing invalid memory

2016-01-31T19:25:50+00:00

[ Upstream commit 320f1a4a175e7cd5d3f006f92b4d4d3e2cbb7bb5 ]

proc_dostring() needs an initialized destination string, while the one
provided in proc_sctp_do_hmac_alg() contains stack garbage.

Thus, writing to cookie_hmac_alg would strlen() that garbage and end up
accessing invalid memory.

Fixes: 3c68198e7 ("sctp: Make hmac algorithm selection for cookie generation dynamic")
Signed-off-by: Sasha Levin 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sctp: sctp should release assoc when sctp_make_abort_user return NULL in sctp_close

2016-01-31T19:25:49+00:00

[ Upstream commit 068d8bd338e855286aea54e70d1c101569284b21 ]

In sctp_close, sctp_make_abort_user may return NULL because of memory
allocation failure. If this happens, it will bypass any state change
and never free the assoc. The assoc has no chance to be freed and it
will be kept in memory with the state it had even after the socket is
closed by sctp_close().

So if sctp_make_abort_user fails to allocate memory, we should abort
the asoc via sctp_primitive_ABORT as well. Just like the annotation in
sctp_sf_cookie_wait_prm_abort and sctp_sf_do_9_1_prm_abort said,
"Even if we can't send the ABORT due to low memory delete the TCB.
This is a departure from our typical NOMEM handling".

But then the chunk is NULL (low memory) and the SCTP_CMD_REPLY cmd would
dereference the chunk pointer, and system crash. So we should add
SCTP_CMD_REPLY cmd only when the chunk is not NULL, just like other
places where it adds SCTP_CMD_REPLY cmd.

Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: sctp: clone options to avoid use after free

2016-01-23T04:55:46+00:00

[ Upstream commit 9470e24f35ab81574da54e69df90c1eb4a96b43f ]

SCTP is lacking proper np->opt cloning at accept() time.

TCP and DCCP use ipv6_dup_options() helper, do the same
in SCTP.

We might later factorize this code in a common helper to avoid
future mistakes.

Reported-by: Dmitry Vyukov 
Signed-off-by: Eric Dumazet 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sctp: also copy sk_tsflags when copying the socket

2016-01-23T04:55:45+00:00

[ Upstream commit 50a5ffb1ef535e3c6989711c51b5d61b543a3b45 ]

As we are keeping timestamps on when copying the socket, we also have to
copy sk_tsflags.

This is needed since b9f40e21ef42 ("net-timestamp: move timestamp flags
out of sk_flags").

Signed-off-by: Marcelo Ricardo Leitner 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sctp: update the netstamp_needed counter when copying sockets

2016-01-23T04:55:44+00:00

[ Upstream commit 01ce63c90170283a9855d1db4fe81934dddce648 ]

Dmitry Vyukov reported that SCTP was triggering a WARN on socket destroy
related to disabling sock timestamp.

When SCTP accepts an association or peel one off, it copies sock flags
but forgot to call net_enable_timestamp() if a packet timestamping flag
was copied, leading to extra calls to net_disable_timestamp() whenever
such clones were closed.

The fix is to call net_enable_timestamp() whenever we copy a sock with
that flag on, like tcp does.

Reported-by: Dmitry Vyukov 
Signed-off-by: Marcelo Ricardo Leitner 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

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

2016-01-23T04:55:44+00:00

[ Upstream commit cb5e173ed7c03a0d4630ce68a95a186cce3cc872 ]

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 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: sctp: implement sctp_v6_destroy_sock()

2015-12-15T05:41:04+00:00

[ Upstream commit 602dd62dfbda3e63a2d6a3cbde953ebe82bf5087 ]

Dmitry Vyukov reported a memory leak using IPV6 SCTP sockets.

We need to call inet6_destroy_sock() to properly release
inet6 specific fields.

Reported-by: Dmitry Vyukov 
Signed-off-by: Eric Dumazet 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sctp: translate host order to network order when setting a hmacid

2015-12-15T05:40:58+00:00

[ Upstream commit ed5a377d87dc4c87fb3e1f7f698cba38cd893103 ]

now sctp auth cannot work well when setting a hmacid manually, which
is caused by that we didn't use the network order for hmacid, so fix
it by adding the transformation in sctp_auth_ep_set_hmacs.

even we set hmacid with the network order in userspace, it still
can't work, because of this condition in sctp_auth_ep_set_hmacs():

		if (id > SCTP_AUTH_HMAC_ID_MAX)
			return -EOPNOTSUPP;

so this wasn't working before and thus it won't break compatibility.

Fixes: 65b07e5d0d09 ("[SCTP]: API updates to suport SCTP-AUTH extensions.")
Signed-off-by: Xin Long 
Signed-off-by: Marcelo Ricardo Leitner 
Acked-by: Neil Horman 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: sctp: Don't use 64 kilobyte lookup table for four elements

2015-09-29T05:52:21+00:00

Seemingly innocuous sctp_trans_state_to_prio_map[] array
is way bigger than it looks, since
"[SCTP_UNKNOWN] = 2" expands into "[0xffff] = 2" !

This patch replaces it with switch() statement.

Signed-off-by: Denys Vlasenko 
CC: Vlad Yasevich 
CC: Neil Horman 
CC: Marcelo Ricardo Leitner 
CC: linux-sctp@vger.kernel.org
CC: netdev@vger.kernel.org
CC: linux-kernel@vger.kernel.org
Acked-by: Marcelo Ricardo Leitner 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller

sctp: Prevent soft lockup when sctp_accept() is called during a timeout event

2015-09-29T04:03:40+00:00

A case can occur when sctp_accept() is called by the user during
a heartbeat timeout event after the 4-way handshake.  Since
sctp_assoc_migrate() changes both assoc->base.sk and assoc->ep, the
bh_sock_lock in sctp_generate_heartbeat_event() will be taken with
the listening socket but released with the new association socket.
The result is a deadlock on any future attempts to take the listening
socket lock.

Note that this race can occur with other SCTP timeouts that take
the bh_lock_sock() in the event sctp_accept() is called.

 BUG: soft lockup - CPU#9 stuck for 67s! [swapper:0]
 ...
 RIP: 0010:[]  [] _spin_lock+0x1e/0x30
 RSP: 0018:ffff880028323b20  EFLAGS: 00000206
 RAX: 0000000000000002 RBX: ffff880028323b20 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffff880028323be0 RDI: ffff8804632c4b48
 RBP: ffffffff8100bb93 R08: 0000000000000000 R09: 0000000000000000
 R10: ffff880610662280 R11: 0000000000000100 R12: ffff880028323aa0
 R13: ffff8804383c3880 R14: ffff880028323a90 R15: ffffffff81534225
 FS:  0000000000000000(0000) GS:ffff880028320000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
 CR2: 00000000006df528 CR3: 0000000001a85000 CR4: 00000000000006e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process swapper (pid: 0, threadinfo ffff880616b70000, task ffff880616b6cab0)
 Stack:
 ffff880028323c40 ffffffffa01c2582 ffff880614cfb020 0000000000000000
  0100000000000000 00000014383a6c44 ffff8804383c3880 ffff880614e93c00
  ffff880614e93c00 0000000000000000 ffff8804632c4b00 ffff8804383c38b8
 Call Trace:
 
 [] ? sctp_rcv+0x492/0xa10 [sctp]
 [] ? nf_iterate+0x69/0xb0
 [] ? ip_local_deliver_finish+0x0/0x2d0
 [] ? nf_hook_slow+0x76/0x120
 [] ? ip_local_deliver_finish+0x0/0x2d0
 [] ? ip_local_deliver_finish+0xdd/0x2d0
 [] ? ip_local_deliver+0x98/0xa0
 [] ? ip_rcv_finish+0x12d/0x440
 [] ? ip_rcv+0x275/0x350
 [] ? __netif_receive_skb+0x4ab/0x750
 ...

With lockdep debugging:

 =====================================
 [ BUG: bad unlock balance detected! ]
 -------------------------------------
 CslRx/12087 is trying to release lock (slock-AF_INET) at:
 [] sctp_generate_timeout_event+0x40/0xe0 [sctp]
 but there are no more locks to release!

 other info that might help us debug this:
 2 locks held by CslRx/12087:
 #0:  (&asoc->timers[i]){+.-...}, at: [] run_timer_softirq+0x16f/0x3e0
 #1:  (slock-AF_INET){+.-...}, at: [] sctp_generate_timeout_event+0x23/0xe0 [sctp]

Ensure the socket taken is also the same one that is released by
saving a copy of the socket before entering the timeout event
critical section.

Signed-off-by: Karl Heiss 
Signed-off-by: David S. Miller