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

[ Upstream commit c485658bae87faccd7aed540fd2ca3ab37992310 ]

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.

Change-Id: I47e5eed6d37c4724c48868dbbdeb314892ce2c1a
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bridge: multicast: add sanity check for query source addresses

[ Upstream commit 6565b9eeef194afbb3beec80d6dd2447f4091f8c ]

MLD queries are supposed to have an IPv6 link-local source address
according to RFC2710, section 4 and RFC3810, section 5.1.14. This patch
adds a sanity check to ignore such broken MLD queries.

Without this check, such malformed MLD queries can result in a
denial of service: The queries are ignored by any MLD listener
therefore they will not respond with an MLD report. However,
without this patch these malformed MLD queries would enable the
snooping part in the bridge code, potentially shutting down the
according ports towards these hosts for multicast traffic as the
bridge did not learn about these listeners.

Change-Id: Iaa8b9383099270065c4c006aeb48d0d889361e6b
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: unix: non blocking recvmsg() should not return -EINTR

[ Upstream commit de1443916791d75fdd26becb116898277bb0273f ]

Some applications didn't expect recvmsg() on a non blocking socket
could return -EINTR. This possibility was added as a side effect
of commit b3ca9b02b00704 ("net: fix multithreaded signal handling in
unix recv routines").

To hit this bug, you need to be a bit unlucky, as the u->readlock
mutex is usually held for very small periods.

Change-Id: I6c6c0ea69553a2b7addd39812be44dcc2f2fa9ab
Fixes: b3ca9b02b00704 ("net: fix multithreaded signal handling in unix recv routines")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Rainer Weikusat <rweikusat@mobileactivedefense.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>