linux-toradex.git/net/l2tp, branch v4.10

l2tp: do not use udp_ioctl()

2017-02-10T20:57:34+00:00

udp_ioctl(), as its name suggests, is used by UDP protocols,
but is also used by L2TP :(

L2TP should use its own handler, because it really does not
look the same.

SIOCINQ for instance should not assume UDP checksum or headers.

Thanks to Andrey and syzkaller team for providing the report
and a nice reproducer.

While crashes only happen on recent kernels (after commit
7c13f97ffde6 ("udp: do fwd memory scheduling on dequeue")), this
probably needs to be backported to older kernels.

Fixes: 7c13f97ffde6 ("udp: do fwd memory scheduling on dequeue")
Fixes: 85584672012e ("udp: Fix udp_poll() and ioctl()")
Signed-off-by: Eric Dumazet 
Reported-by: Andrey Konovalov 
Acked-by: Paolo Abeni 
Signed-off-by: David S. Miller

l2tp: take remote address into account in l2tp_ip and l2tp_ip6 socket lookups

2017-01-02T03:07:20+00:00

For connected sockets, __l2tp_ip{,6}_bind_lookup() needs to check the
remote IP when looking for a matching socket. Otherwise a connected
socket can receive traffic not originating from its peer.

Drop l2tp_ip_bind_lookup() and l2tp_ip6_bind_lookup() instead of
updating their prototype, as these functions aren't used.

Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller

l2tp: consider '::' as wildcard address in l2tp_ip6 socket lookup

2017-01-02T03:07:20+00:00

An L2TP socket bound to the unspecified address should match with any
address. If not, it can't receive any packet and __l2tp_ip6_bind_lookup()
can't prevent another socket from binding on the same device/tunnel ID.

While there, rename the 'addr' variable to 'sk_laddr' (local addr), to
make following patch clearer.

Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller

net: l2tp: ppp: change PPPOL2TP_MSG_* => L2TP_MSG_*

2016-12-11T04:29:11+00:00

Signed-off-by: Asbjoern Sloth Toennesen 
Signed-off-by: David S. Miller

net: l2tp: export debug flags to UAPI

2016-12-11T04:29:11+00:00

Move the L2TP_MSG_* definitions to UAPI, as it is part of
the netlink API.

Signed-off-by: Asbjoern Sloth Toennesen 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-12-03T17:29:53+00:00

Couple conflicts resolved here:

1) In the MACB driver, a bug fix to properly initialize the
   RX tail pointer properly overlapped with some changes
   to support variable sized rings.

2) In XGBE we had a "CONFIG_PM" --> "CONFIG_PM_SLEEP" fix
   overlapping with a reorganization of the driver to support
   ACPI, OF, as well as PCI variants of the chip.

3) In 'net' we had several probe error path bug fixes to the
   stmmac driver, meanwhile a lot of this code was cleaned up
   and reorganized in 'net-next'.

4) The cls_flower classifier obtained a helper function in
   'net-next' called __fl_delete() and this overlapped with
   Daniel Borkamann's bug fix to use RCU for object destruction
   in 'net'.  It also overlapped with Jiri's change to guard
   the rhashtable_remove_fast() call with a check against
   tc_skip_sw().

5) In mlx4, a revert bug fix in 'net' overlapped with some
   unrelated changes in 'net-next'.

6) In geneve, a stale header pointer after pskb_expand_head()
   bug fix in 'net' overlapped with a large reorganization of
   the same code in 'net-next'.  Since the 'net-next' code no
   longer had the bug in question, there was nothing to do
   other than to simply take the 'net-next' hunks.

Signed-off-by: David S. Miller

l2tp: fix address test in __l2tp_ip6_bind_lookup()

2016-11-30T19:14:08+00:00

The '!(addr && ipv6_addr_equal(addr, laddr))' part of the conditional
matches if addr is NULL or if addr != laddr.
But the intend of __l2tp_ip6_bind_lookup() is to find a sockets with
the same address, so the ipv6_addr_equal() condition needs to be
inverted.

For better clarity and consistency with the rest of the expression, the
(!X || X == Y) notation is used instead of !(X && X != Y).

Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller

l2tp: fix lookup for sockets not bound to a device in l2tp_ip

2016-11-30T19:14:08+00:00

When looking up an l2tp socket, we must consider a null netdevice id as
wild card. There are currently two problems caused by
__l2tp_ip_bind_lookup() not considering 'dif' as wild card when set to 0:

  * A socket bound to a device (i.e. with sk->sk_bound_dev_if != 0)
    never receives any packet. Since __l2tp_ip_bind_lookup() is called
    with dif == 0 in l2tp_ip_recv(), sk->sk_bound_dev_if is always
    different from 'dif' so the socket doesn't match.

  * Two sockets, one bound to a device but not the other, can be bound
    to the same address. If the first socket binding to the address is
    the one that is also bound to a device, the second socket can bind
    to the same address without __l2tp_ip_bind_lookup() noticing the
    overlap.

To fix this issue, we need to consider that any null device index, be
it 'sk->sk_bound_dev_if' or 'dif', matches with any other value.
We also need to pass the input device index to __l2tp_ip_bind_lookup()
on reception so that sockets bound to a device never receive packets
from other devices.

This patch fixes l2tp_ip6 in the same way.

Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller

l2tp: fix racy socket lookup in l2tp_ip and l2tp_ip6 bind()

2016-11-30T19:14:08+00:00

It's not enough to check for sockets bound to same address at the
beginning of l2tp_ip{,6}_bind(): even if no socket is found at that
time, a socket with the same address could be bound before we take
the l2tp lock again.

This patch moves the lookup right before inserting the new socket, so
that no change can ever happen to the list between address lookup and
socket insertion.

Care is taken to avoid side effects on the socket in case of failure.
That is, modifications of the socket are done after the lookup, when
binding is guaranteed to succeed, and before releasing the l2tp lock,
so that concurrent lookups will always see fully initialised sockets.

For l2tp_ip, 'ret' is set to -EINVAL before checking the SOCK_ZAPPED
bit. Error code was mistakenly set to -EADDRINUSE on error by commit
32c231164b76 ("l2tp: fix racy SOCK_ZAPPED flag check in l2tp_ip{,6}_bind()").
Using -EINVAL restores original behaviour.

For l2tp_ip6, the lookup is now always done with the correct bound
device. Before this patch, when binding to a link-local address, the
lookup was done with the original sk->sk_bound_dev_if, which was later
overwritten with addr->l2tp_scope_id. Lookup is now performed with the
final sk->sk_bound_dev_if value.

Finally, the (addr_len >= sizeof(struct sockaddr_in6)) check has been
dropped: addr is a sockaddr_l2tpip6 not sockaddr_in6 and addr_len has
already been checked at this point (this part of the code seems to have
been copy-pasted from net/ipv6/raw.c).

Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller

l2tp: hold socket before dropping lock in l2tp_ip{, 6}_recv()

2016-11-30T19:14:07+00:00

Socket must be held while under the protection of the l2tp lock; there
is no guarantee that sk remains valid after the read_unlock_bh() call.

Same issue for l2tp_ip and l2tp_ip6.

Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller