Commit Graph

102 Commits

Author SHA1 Message Date
David S. Miller
5cd3da4ba2 Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net
Simple overlapping changes in stmmac driver.

Adjust skb_gro_flush_final_remcsum function signature to make GRO list
changes in net-next, as per Stephen Rothwell's example merge
resolution.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-03 10:29:26 +09:00
Linus Torvalds
a11e1d432b Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL
The poll() changes were not well thought out, and completely
unexplained.  They also caused a huge performance regression, because
"->poll()" was no longer a trivial file operation that just called down
to the underlying file operations, but instead did at least two indirect
calls.

Indirect calls are sadly slow now with the Spectre mitigation, but the
performance problem could at least be largely mitigated by changing the
"->get_poll_head()" operation to just have a per-file-descriptor pointer
to the poll head instead.  That gets rid of one of the new indirections.

But that doesn't fix the new complexity that is completely unwarranted
for the regular case.  The (undocumented) reason for the poll() changes
was some alleged AIO poll race fixing, but we don't make the common case
slower and more complex for some uncommon special case, so this all
really needs way more explanations and most likely a fundamental
redesign.

[ This revert is a revert of about 30 different commits, not reverted
  individually because that would just be unnecessarily messy  - Linus ]

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-28 10:40:47 -07:00
Guillaume Nault
a408194aa0 l2tp: define helper for parsing struct sockaddr_pppol2tp*
'sockaddr_len' is checked against various values when entering
pppol2tp_connect(), to verify its validity. It is used again later, to
find out which sockaddr structure was passed from user space. This
patch combines these two operations into one new function in order to
simplify pppol2tp_connect().

A new structure, l2tp_connect_info, is used to pass sockaddr data back
to pppol2tp_connect(), to avoid passing too many parameters to
l2tp_sockaddr_get_info(). Also, the first parameter is void* in order
to avoid casting between all sockaddr_* structures manually.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-28 16:06:50 +09:00
Guillaume Nault
877375e485 l2tp: remove pppol2tp_session_close()
l2tp_core.c verifies that ->session_close() is defined before calling
it. There's no need for a stub.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26 22:55:51 +09:00
Guillaume Nault
ecd012e45a l2tp: filter out non-PPP sessions in pppol2tp_tunnel_ioctl()
pppol2tp_tunnel_ioctl() can act on an L2TPv3 tunnel, in which case
'session' may be an Ethernet pseudo-wire.

However, pppol2tp_session_ioctl() expects a PPP pseudo-wire, as it
assumes l2tp_session_priv() points to a pppol2tp_session structure. For
an Ethernet pseudo-wire l2tp_session_priv() points to an l2tp_eth_sess
structure instead, making pppol2tp_session_ioctl() access invalid
memory.

Fixes: d9e31d17ce ("l2tp: Add L2TP ethernet pseudowire support")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-15 09:12:37 -07:00
Guillaume Nault
bda06be215 l2tp: clean up stale tunnel or session in pppol2tp_connect's error path
pppol2tp_connect() may create a tunnel or a session. Remove them in
case of error.

Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-14 17:10:19 -07:00
Guillaume Nault
3e1bc8bf97 l2tp: prevent pppol2tp_connect() from creating kernel sockets
If 'fd' is negative, l2tp_tunnel_create() creates a tunnel socket using
the configuration passed in 'tcfg'. Currently, pppol2tp_connect() sets
the relevant fields to zero, tricking l2tp_tunnel_create() into setting
up an unusable kernel socket.

We can't set 'tcfg' with the required fields because there's no way to
get them from the current connect() parameters. So let's restrict
kernel sockets creation to the netlink API, which is the original use
case.

Fixes: 789a4a2c61 ("l2tp: Add support for static unmanaged L2TPv3 tunnels")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-14 17:10:19 -07:00
Guillaume Nault
7ac6ab1f8a l2tp: only accept PPP sessions in pppol2tp_connect()
l2tp_session_priv() returns a struct pppol2tp_session pointer only for
PPPoL2TP sessions. In particular, if the session is an L2TP_PWTYPE_ETH
pseudo-wire, l2tp_session_priv() returns a pointer to an l2tp_eth_sess
structure, which is much smaller than struct pppol2tp_session. This
leads to invalid memory dereference when trying to lock ps->sk_lock.

Fixes: d9e31d17ce ("l2tp: Add L2TP ethernet pseudowire support")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-14 17:10:19 -07:00
Guillaume Nault
90904ff5f9 l2tp: fix pseudo-wire type for sessions created by pppol2tp_connect()
Define cfg.pw_type so that the new session is created with its .pwtype
field properly set (L2TP_PWTYPE_PPP).

Not setting the pseudo-wire type had several annoying effects:

  * Invalid value returned in the L2TP_ATTR_PW_TYPE attribute when
    dumping sessions with the netlink API.

  * Impossibility to delete the session using the netlink API (because
    l2tp_nl_cmd_session_delete() gets the deletion callback function
    from an array indexed by the session's pseudo-wire type).

Also, there are several cases where we should check a session's
pseudo-wire type. For example, pppol2tp_connect() should refuse to
connect a session that is not PPPoL2TP, but that requires the session's
.pwtype field to be properly set.

Fixes: f7faffa3ff ("l2tp: Add L2TPv3 protocol support")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-14 17:10:19 -07:00
Linus Torvalds
1c8c5a9d38 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) Add Maglev hashing scheduler to IPVS, from Inju Song.

 2) Lots of new TC subsystem tests from Roman Mashak.

 3) Add TCP zero copy receive and fix delayed acks and autotuning with
    SO_RCVLOWAT, from Eric Dumazet.

 4) Add XDP_REDIRECT support to mlx5 driver, from Jesper Dangaard
    Brouer.

 5) Add ttl inherit support to vxlan, from Hangbin Liu.

 6) Properly separate ipv6 routes into their logically independant
    components. fib6_info for the routing table, and fib6_nh for sets of
    nexthops, which thus can be shared. From David Ahern.

 7) Add bpf_xdp_adjust_tail helper, which can be used to generate ICMP
    messages from XDP programs. From Nikita V. Shirokov.

 8) Lots of long overdue cleanups to the r8169 driver, from Heiner
    Kallweit.

 9) Add BTF ("BPF Type Format"), from Martin KaFai Lau.

10) Add traffic condition monitoring to iwlwifi, from Luca Coelho.

11) Plumb extack down into fib_rules, from Roopa Prabhu.

12) Add Flower classifier offload support to igb, from Vinicius Costa
    Gomes.

13) Add UDP GSO support, from Willem de Bruijn.

14) Add documentation for eBPF helpers, from Quentin Monnet.

15) Add TLS tx offload to mlx5, from Ilya Lesokhin.

16) Allow applications to be given the number of bytes available to read
    on a socket via a control message returned from recvmsg(), from
    Soheil Hassas Yeganeh.

17) Add x86_32 eBPF JIT compiler, from Wang YanQing.

18) Add AF_XDP sockets, with zerocopy support infrastructure as well.
    From Björn Töpel.

19) Remove indirect load support from all of the BPF JITs and handle
    these operations in the verifier by translating them into native BPF
    instead. From Daniel Borkmann.

20) Add GRO support to ipv6 gre tunnels, from Eran Ben Elisha.

21) Allow XDP programs to do lookups in the main kernel routing tables
    for forwarding. From David Ahern.

22) Allow drivers to store hardware state into an ELF section of kernel
    dump vmcore files, and use it in cxgb4. From Rahul Lakkireddy.

23) Various RACK and loss detection improvements in TCP, from Yuchung
    Cheng.

24) Add TCP SACK compression, from Eric Dumazet.

25) Add User Mode Helper support and basic bpfilter infrastructure, from
    Alexei Starovoitov.

26) Support ports and protocol values in RTM_GETROUTE, from Roopa
    Prabhu.

27) Support bulking in ->ndo_xdp_xmit() API, from Jesper Dangaard
    Brouer.

28) Add lots of forwarding selftests, from Petr Machata.

29) Add generic network device failover driver, from Sridhar Samudrala.

* ra.kernel.org:/pub/scm/linux/kernel/git/davem/net-next: (1959 commits)
  strparser: Add __strp_unpause and use it in ktls.
  rxrpc: Fix terminal retransmission connection ID to include the channel
  net: hns3: Optimize PF CMDQ interrupt switching process
  net: hns3: Fix for VF mailbox receiving unknown message
  net: hns3: Fix for VF mailbox cannot receiving PF response
  bnx2x: use the right constant
  Revert "net: sched: cls: Fix offloading when ingress dev is vxlan"
  net: dsa: b53: Fix for brcm tag issue in Cygnus SoC
  enic: fix UDP rss bits
  netdev-FAQ: clarify DaveM's position for stable backports
  rtnetlink: validate attributes in do_setlink()
  mlxsw: Add extack messages for port_{un, }split failures
  netdevsim: Add extack error message for devlink reload
  devlink: Add extack to reload and port_{un, }split operations
  net: metrics: add proper netlink validation
  ipmr: fix error path when ipmr_new_table fails
  ip6mr: only set ip6mr_table from setsockopt when ip6mr_new_table succeeds
  net: hns3: remove unused hclgevf_cfg_func_mta_filter
  netfilter: provide udp*_lib_lookup for nf_tproxy
  qed*: Utilize FW 8.37.2.0
  ...
2018-06-06 18:39:49 -07:00
Guillaume Nault
3d609342cc l2tp: fix refcount leakage on PPPoL2TP sockets
Commit d02ba2a611 ("l2tp: fix race in pppol2tp_release with session
object destroy") tried to fix a race condition where a PPPoL2TP socket
would disappear while the L2TP session was still using it. However, it
missed the root issue which is that an L2TP session may accept to be
reconnected if its associated socket has entered the release process.

The tentative fix makes the session hold the socket it is connected to.
That saves the kernel from crashing, but introduces refcount leakage,
preventing the socket from completing the release process. Once stalled,
everything the socket depends on can't be released anymore, including
the L2TP session and the l2tp_ppp module.

The root issue is that, when releasing a connected PPPoL2TP socket, the
session's ->sk pointer (RCU-protected) is reset to NULL and we have to
wait for a grace period before destroying the socket. The socket drops
the session in its ->sk_destruct callback function, so the session
will exist until the last reference on the socket is dropped.
Therefore, there is a time frame where pppol2tp_connect() may accept
reconnecting a session, as it only checks ->sk to figure out if the
session is connected. This time frame is shortened by the fact that
pppol2tp_release() calls l2tp_session_delete(), making the session
unreachable before resetting ->sk. However, pppol2tp_connect() may
grab the session before it gets unhashed by l2tp_session_delete(), but
it may test ->sk after the later got reset. The race is not so hard to
trigger and syzbot found a pretty reliable reproducer:
https://syzkaller.appspot.com/bug?id=418578d2a4389074524e04d641eacb091961b2cf

Before d02ba2a611, another race could let pppol2tp_release()
overwrite the ->__sk pointer of an L2TP session, thus tricking
pppol2tp_put_sk() into calling sock_put() on a socket that is different
than the one for which pppol2tp_release() was originally called. To get
there, we had to trigger the race described above, therefore having one
PPPoL2TP socket being released, while the session it is connected to is
reconnecting to a different PPPoL2TP socket. When releasing this new
socket fast enough, pppol2tp_release() overwrites the session's
->__sk pointer with the address of the new socket, before the first
pppol2tp_put_sk() call gets scheduled. Then the pppol2tp_put_sk() call
invoked by the original socket will sock_put() the new socket,
potentially dropping its last reference. When the second
pppol2tp_put_sk() finally runs, its socket has already been freed.

With d02ba2a611, the session takes a reference on both sockets.
Furthermore, the session's ->sk pointer is reset in the
pppol2tp_session_close() callback function rather than in
pppol2tp_release(). Therefore, ->__sk can't be overwritten and
pppol2tp_put_sk() is called only once (l2tp_session_delete() will only
run pppol2tp_session_close() once, to protect the session against
concurrent deletion requests). Now pppol2tp_put_sk() will properly
sock_put() the original socket, but the new socket will remain, as
l2tp_session_delete() prevented the release process from completing.
Here, we don't depend on the ->__sk race to trigger the bug. Getting
into the pppol2tp_connect() race is enough to leak the reference, no
matter when new socket is released.

So it all boils down to pppol2tp_connect() failing to realise that the
session has already been connected. This patch drops the unneeded extra
reference counting (mostly reverting d02ba2a611) and checks that
neither ->sk nor ->__sk is set before allowing a session to be
connected.

Fixes: d02ba2a611 ("l2tp: fix race in pppol2tp_release with session object destroy")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-05 09:40:18 -04:00
Linus Torvalds
408afb8d78 Merge branch 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull aio updates from Al Viro:
 "Majority of AIO stuff this cycle. aio-fsync and aio-poll, mostly.

  The only thing I'm holding back for a day or so is Adam's aio ioprio -
  his last-minute fixup is trivial (missing stub in !CONFIG_BLOCK case),
  but let it sit in -next for decency sake..."

* 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  aio: sanitize the limit checking in io_submit(2)
  aio: fold do_io_submit() into callers
  aio: shift copyin of iocb into io_submit_one()
  aio_read_events_ring(): make a bit more readable
  aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way
  aio: take list removal to (some) callers of aio_complete()
  aio: add missing break for the IOCB_CMD_FDSYNC case
  random: convert to ->poll_mask
  timerfd: convert to ->poll_mask
  eventfd: switch to ->poll_mask
  pipe: convert to ->poll_mask
  crypto: af_alg: convert to ->poll_mask
  net/rxrpc: convert to ->poll_mask
  net/iucv: convert to ->poll_mask
  net/phonet: convert to ->poll_mask
  net/nfc: convert to ->poll_mask
  net/caif: convert to ->poll_mask
  net/bluetooth: convert to ->poll_mask
  net/sctp: convert to ->poll_mask
  net/tipc: convert to ->poll_mask
  ...
2018-06-04 13:57:43 -07:00
Christoph Hellwig
db5051ead6 net: convert datagram_poll users tp ->poll_mask
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26 09:16:44 +02:00
Christoph Hellwig
c350637227 proc: introduce proc_create_net{,_data}
Variants of proc_create{,_data} that directly take a struct seq_operations
and deal with network namespaces in ->open and ->release.  All callers of
proc_create + seq_open_net converted over, and seq_{open,release}_net are
removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-16 07:24:30 +02:00
Guillaume Nault
8349440733 l2tp: consistent reference counting in procfs and debufs
The 'pppol2tp' procfs and 'l2tp/tunnels' debugfs files handle reference
counting of sessions differently than for tunnels.

For consistency, use the same mechanism for handling both sessions and
tunnels. That is, drop the reference on the previous session just
before looking up the next one (rather than in .show()). If necessary
(if dump stops before *_next_session() returns NULL), drop the last
reference in .stop().

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-27 11:06:35 -04:00
Guillaume Nault
eb1c28c058 l2tp: check sockaddr length in pppol2tp_connect()
Check sockaddr_len before dereferencing sp->sa_protocol, to ensure that
it actually points to valid data.

Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Reported-by: syzbot+a70ac890b23b1bf29f5c@syzkaller.appspotmail.com
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-23 21:10:43 -04:00
Guillaume Nault
5411b6187a l2tp: fix {pppol2tp, l2tp_dfs}_seq_stop() in case of seq_file overflow
Commit 0e0c3fee3a ("l2tp: hold reference on tunnels printed in pppol2tp proc file")
assumed that if pppol2tp_seq_stop() was called with non-NULL private
data (the 'v' pointer), then pppol2tp_seq_start() would not be called
again. It turns out that this isn't guaranteed, and overflowing the
seq_file's buffer in pppol2tp_seq_show() is a way to get into this
situation.

Therefore, pppol2tp_seq_stop() needs to reset pd->tunnel, so that
pppol2tp_seq_start() won't drop a reference again if it gets called.
We also have to clear pd->session, because the rest of the code expects
a non-NULL tunnel when pd->session is set.

The l2tp_debugfs module has the same issue. Fix it in the same way.

Fixes: 0e0c3fee3a ("l2tp: hold reference on tunnels printed in pppol2tp proc file")
Fixes: f726214d9b ("l2tp: hold reference on tunnels printed in l2tp/tunnels debugfs file")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-22 14:46:35 -04:00
Guillaume Nault
0e0c3fee3a l2tp: hold reference on tunnels printed in pppol2tp proc file
Use l2tp_tunnel_get_nth() instead of l2tp_tunnel_find_nth(), to be safe
against concurrent tunnel deletion.

Unlike sessions, we can't drop the reference held on tunnels in
pppol2tp_seq_show(). Tunnels are reused across several calls to
pppol2tp_seq_start() when iterating over sessions. These iterations
need the tunnel for accessing the next session. Therefore the only safe
moment for dropping the reference is just before searching for the next
tunnel.

Normally, the last invocation of pppol2tp_next_tunnel() doesn't find
any new tunnel, so it drops the last tunnel without taking any new
reference. However, in case of error, pppol2tp_seq_stop() is called
directly, so we have to drop the reference there.

Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-13 12:17:26 -04:00
Guillaume Nault
6b9f34239b l2tp: fix races in tunnel creation
l2tp_tunnel_create() inserts the new tunnel into the namespace's tunnel
list and sets the socket's ->sk_user_data field, before returning it to
the caller. Therefore, there are two ways the tunnel can be accessed
and freed, before the caller even had the opportunity to take a
reference. In practice, syzbot could crash the module by closing the
socket right after a new tunnel was returned to pppol2tp_create().

This patch moves tunnel registration out of l2tp_tunnel_create(), so
that the caller can safely hold a reference before publishing the
tunnel. This second step is done with the new l2tp_tunnel_register()
function, which is now responsible for associating the tunnel to its
socket and for inserting it into the namespace's list.

While moving the code to l2tp_tunnel_register(), a few modifications
have been done. First, the socket validation tests are done in a helper
function, for clarity. Also, modifying the socket is now done after
having inserted the tunnel to the namespace's tunnels list. This will
allow insertion to fail, without having to revert theses modifications
in the error path (a followup patch will check for duplicate tunnels
before insertion). Either the socket is a kernel socket which we
control, or it is a user-space socket for which we have a reference on
the file descriptor. In any case, the socket isn't going to be closed
from under us.

Reported-by: syzbot+fbeeb5c3b538e8545644@syzkaller.appspotmail.com
Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11 17:41:27 -04:00
Kirill Tkhai
2f635ceeb2 net: Drop pernet_operations::async
Synchronous pernet_operations are not allowed anymore.
All are asynchronous. So, drop the structure member.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27 13:18:09 -04:00
Joe Perches
d6444062f8 net: Use octal not symbolic permissions
Prefer the direct use of octal for permissions.

Done with checkpatch -f --types=SYMBOLIC_PERMS --fix-inplace
and some typing.

Miscellanea:

o Whitespace neatening around these conversions.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-26 12:07:48 -04:00
David S. Miller
0f3e9c97eb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
All of the conflicts were cases of overlapping changes.

In net/core/devlink.c, we have to make care that the
resouce size_params have become a struct member rather
than a pointer to such an object.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-06 01:20:46 -05:00
Kirill Tkhai
c80afa026a net: Convert /proc creating and destroying pernet_operations
These pernet_operations just create and destroy /proc entries,
and they can safely marked as async:

pppoe_net_ops
vlan_net_ops
canbcm_pernet_ops
kcm_net_ops
pfkey_net_ops
pppol2tp_net_ops
phonet_net_ops

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-27 11:01:35 -05:00
James Chapman
d02ba2a611 l2tp: fix race in pppol2tp_release with session object destroy
pppol2tp_release uses call_rcu to put the final ref on its socket. But
the session object doesn't hold a ref on the session socket so may be
freed while the pppol2tp_put_sk RCU callback is scheduled. Fix this by
having the session hold a ref on its socket until the session is
destroyed. It is this ref that is dropped via call_rcu.

Sessions are also deleted via l2tp_tunnel_closeall. This must now also put
the final ref via call_rcu. So move the call_rcu call site into
pppol2tp_session_close so that this happens in both destroy paths. A
common destroy path should really be implemented, perhaps with
l2tp_tunnel_closeall calling l2tp_session_delete like pppol2tp_release
does, but this will be looked at later.

ODEBUG: activate active (active state 1) object type: rcu_head hint:           (null)
WARNING: CPU: 3 PID: 13407 at lib/debugobjects.c:291 debug_print_object+0x166/0x220
Modules linked in:
CPU: 3 PID: 13407 Comm: syzbot_19c09769 Not tainted 4.16.0-rc2+ #38
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
RIP: 0010:debug_print_object+0x166/0x220
RSP: 0018:ffff880013647a00 EFLAGS: 00010082
RAX: dffffc0000000008 RBX: 0000000000000003 RCX: ffffffff814d3333
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88001a59f6d0
RBP: ffff880013647a40 R08: 0000000000000000 R09: 0000000000000001
R10: ffff8800136479a8 R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff86161420 R14: ffffffff85648b60 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88001a580000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020e77000 CR3: 0000000006022000 CR4: 00000000000006e0
Call Trace:
 debug_object_activate+0x38b/0x530
 ? debug_object_assert_init+0x3b0/0x3b0
 ? __mutex_unlock_slowpath+0x85/0x8b0
 ? pppol2tp_session_destruct+0x110/0x110
 __call_rcu.constprop.66+0x39/0x890
 ? __call_rcu.constprop.66+0x39/0x890
 call_rcu_sched+0x17/0x20
 pppol2tp_release+0x2c7/0x440
 ? fcntl_setlk+0xca0/0xca0
 ? sock_alloc_file+0x340/0x340
 sock_release+0x92/0x1e0
 sock_close+0x1b/0x20
 __fput+0x296/0x6e0
 ____fput+0x1a/0x20
 task_work_run+0x127/0x1a0
 do_exit+0x7f9/0x2ce0
 ? SYSC_connect+0x212/0x310
 ? mm_update_next_owner+0x690/0x690
 ? up_read+0x1f/0x40
 ? __do_page_fault+0x3c8/0xca0
 do_group_exit+0x10d/0x330
 ? do_group_exit+0x330/0x330
 SyS_exit_group+0x22/0x30
 do_syscall_64+0x1e0/0x730
 ? trace_hardirqs_off_thunk+0x1a/0x1c
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f362e471259
RSP: 002b:00007ffe389abe08 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f362e471259
RDX: 00007f362e471259 RSI: 000000000000002e RDI: 0000000000000000
RBP: 00007ffe389abe30 R08: 0000000000000000 R09: 00007f362e944270
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400b60
R13: 00007ffe389abf50 R14: 0000000000000000 R15: 0000000000000000
Code: 8d 3c dd a0 8f 64 85 48 89 fa 48 c1 ea 03 80 3c 02 00 75 7b 48 8b 14 dd a0 8f 64 85 4c 89 f6 48 c7 c7 20 85 64 85 e
8 2a 55 14 ff <0f> 0b 83 05 ad 2a 68 04 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41

Fixes: ee40fb2e1e ("l2tp: protect sock pointer of struct pppol2tp_session with RCU")
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-26 12:20:36 -05:00
James Chapman
225eb26489 l2tp: don't use inet_shutdown on ppp session destroy
Previously, if a ppp session was closed, we called inet_shutdown to mark
the socket as unconnected such that userspace would get errors and
then close the socket. This could race with userspace closing the
socket. Instead, leave userspace to close the socket in its own time
(our session will be detached anyway).

BUG: KASAN: use-after-free in inet_shutdown+0x5d/0x1c0
Read of size 4 at addr ffff880010ea3ac0 by task syzbot_347bd5ac/8296

CPU: 3 PID: 8296 Comm: syzbot_347bd5ac Not tainted 4.16.0-rc1+ #91
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
Call Trace:
 dump_stack+0x101/0x157
 ? inet_shutdown+0x5d/0x1c0
 print_address_description+0x78/0x260
 ? inet_shutdown+0x5d/0x1c0
 kasan_report+0x240/0x360
 __asan_load4+0x78/0x80
 inet_shutdown+0x5d/0x1c0
 ? pppol2tp_show+0x80/0x80
 pppol2tp_session_close+0x68/0xb0
 l2tp_tunnel_closeall+0x199/0x210
 ? udp_v6_flush_pending_frames+0x90/0x90
 l2tp_udp_encap_destroy+0x6b/0xc0
 ? l2tp_tunnel_del_work+0x2e0/0x2e0
 udpv6_destroy_sock+0x8c/0x90
 sk_common_release+0x47/0x190
 udp_lib_close+0x15/0x20
 inet_release+0x85/0xd0
 inet6_release+0x43/0x60
 sock_release+0x53/0x100
 ? sock_alloc_file+0x260/0x260
 sock_close+0x1b/0x20
 __fput+0x19f/0x380
 ____fput+0x1a/0x20
 task_work_run+0xd2/0x110
 exit_to_usermode_loop+0x18d/0x190
 do_syscall_64+0x389/0x3b0
 entry_SYSCALL_64_after_hwframe+0x26/0x9b
RIP: 0033:0x7fe240a45259
RSP: 002b:00007fe241132df8 EFLAGS: 00000297 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fe240a45259
RDX: 00007fe240a45259 RSI: 0000000000000000 RDI: 00000000000000a5
RBP: 00007fe241132e20 R08: 00007fe241133700 R09: 0000000000000000
R10: 00007fe241133700 R11: 0000000000000297 R12: 0000000000000000
R13: 00007ffc49aff84f R14: 0000000000000000 R15: 00007fe241141040

Allocated by task 8331:
 save_stack+0x43/0xd0
 kasan_kmalloc+0xad/0xe0
 kasan_slab_alloc+0x12/0x20
 kmem_cache_alloc+0x144/0x3e0
 sock_alloc_inode+0x22/0x130
 alloc_inode+0x3d/0xf0
 new_inode_pseudo+0x1c/0x90
 sock_alloc+0x30/0x110
 __sock_create+0xaa/0x4c0
 SyS_socket+0xbe/0x130
 do_syscall_64+0x128/0x3b0
 entry_SYSCALL_64_after_hwframe+0x26/0x9b

Freed by task 8314:
 save_stack+0x43/0xd0
 __kasan_slab_free+0x11a/0x170
 kasan_slab_free+0xe/0x10
 kmem_cache_free+0x88/0x2b0
 sock_destroy_inode+0x49/0x50
 destroy_inode+0x77/0xb0
 evict+0x285/0x340
 iput+0x429/0x530
 dentry_unlink_inode+0x28c/0x2c0
 __dentry_kill+0x1e3/0x2f0
 dput.part.21+0x500/0x560
 dput+0x24/0x30
 __fput+0x2aa/0x380
 ____fput+0x1a/0x20
 task_work_run+0xd2/0x110
 exit_to_usermode_loop+0x18d/0x190
 do_syscall_64+0x389/0x3b0
 entry_SYSCALL_64_after_hwframe+0x26/0x9b

Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-26 12:20:36 -05:00
Denys Vlasenko
9b2c45d479 net: make getname() functions return length rather than use int* parameter
Changes since v1:
Added changes in these files:
    drivers/infiniband/hw/usnic/usnic_transport.c
    drivers/staging/lustre/lnet/lnet/lib-socket.c
    drivers/target/iscsi/iscsi_target_login.c
    drivers/vhost/net.c
    fs/dlm/lowcomms.c
    fs/ocfs2/cluster/tcp.c
    security/tomoyo/network.c

Before:
All these functions either return a negative error indicator,
or store length of sockaddr into "int *socklen" parameter
and return zero on success.

"int *socklen" parameter is awkward. For example, if caller does not
care, it still needs to provide on-stack storage for the value
it does not need.

None of the many FOO_getname() functions of various protocols
ever used old value of *socklen. They always just overwrite it.

This change drops this parameter, and makes all these functions, on success,
return length of sockaddr. It's always >= 0 and can be differentiated
from an error.

Tests in callers are changed from "if (err)" to "if (err < 0)", where needed.

rpc_sockname() lost "int buflen" parameter, since its only use was
to be passed to kernel_getsockname() as &buflen and subsequently
not used in any way.

Userspace API is not changed.

    text    data     bss      dec     hex filename
30108430 2633624  873672 33615726 200ef6e vmlinux.before.o
30108109 2633612  873672 33615393 200ee21 vmlinux.o

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: David S. Miller <davem@davemloft.net>
CC: linux-kernel@vger.kernel.org
CC: netdev@vger.kernel.org
CC: linux-bluetooth@vger.kernel.org
CC: linux-decnet-user@lists.sourceforge.net
CC: linux-wireless@vger.kernel.org
CC: linux-rdma@vger.kernel.org
CC: linux-sctp@vger.kernel.org
CC: linux-nfs@vger.kernel.org
CC: linux-x25@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-12 14:15:04 -05:00
Alexey Dobriyan
96890d6252 net: delete /proc THIS_MODULE references
/proc has been ignoring struct file_operations::owner field for 10 years.
Specifically, it started with commit 786d7e1612
("Fix rmmod/read/write races in /proc entries"). Notice the chunk where
inode->i_fop is initialized with proxy struct file_operations for
regular files:

	-               if (de->proc_fops)
	-                       inode->i_fop = de->proc_fops;
	+               if (de->proc_fops) {
	+                       if (S_ISREG(inode->i_mode))
	+                               inode->i_fop = &proc_reg_file_ops;
	+                       else
	+                               inode->i_fop = de->proc_fops;
	+               }

VFS stopped pinning module at this point.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 15:01:33 -05:00
Guillaume Nault
da9ca825ef l2tp: remove the .tunnel_sock field from struct pppol2tp_session
The last user of .tunnel_sock is pppol2tp_connect() which defensively
uses it to verify internal data consistency.

This check isn't necessary: l2tp_session_get() guarantees that the
returned session belongs to the tunnel passed as parameter. And
.tunnel_sock is never updated, so checking that it still points to
the parent tunnel socket is useless; that test can never fail.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-11 22:08:23 +09:00
Guillaume Nault
7198c77aa0 l2tp: avoid using ->tunnel_sock for getting session's parent tunnel
Sessions don't need to use l2tp_sock_to_tunnel(xxx->tunnel_sock) for
accessing their parent tunnel. They have the .tunnel field in the
l2tp_session structure for that. Furthermore, in all these cases, the
session is registered, so we're guaranteed that .tunnel isn't NULL and
that the session properly holds a reference on the tunnel.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-11 22:08:23 +09:00
David S. Miller
ed29668d1a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Smooth Cong Wang's bug fix into 'net-next'.  Basically put
the bulk of the tcf_block_put() logic from 'net' into
tcf_block_put_ext(), but after the offload unbind.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02 15:23:39 +09:00
Guillaume Nault
a4346210c4 l2tp: remove ->ref() and ->deref()
The ->ref() and ->deref() callbacks are unused since PPP stopped using
them in ee40fb2e1e ("l2tp: protect sock pointer of struct pppol2tp_session with RCU").

We can thus remove them from struct l2tp_session and drop the do_ref
parameter of l2tp_session_get*().

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-01 10:57:24 +09:00
Guillaume Nault
f9e56baf03 l2tp: hold tunnel in pppol2tp_connect()
Use l2tp_tunnel_get() in pppol2tp_connect() to ensure the tunnel isn't
going to disappear while processing the rest of the function.

Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-31 10:59:52 +09:00
Guillaume Nault
f98be6c635 l2tp: initialise PPP sessions before registering them
pppol2tp_connect() initialises L2TP sessions after they've been exposed
to the rest of the system by l2tp_session_register(). This puts
sessions into transient states that are the source of several races, in
particular with session's deletion path.

This patch centralises the initialisation code into
pppol2tp_session_init(), which is called before the registration phase.
The only field that can't be set before session registration is the
pppol2tp socket pointer, which has already been converted to RCU. So
pppol2tp_connect() should now be race-free.

The session's .session_close() callback is now set before registration.
Therefore, it's always called when l2tp_core deletes the session, even
if it was created by pppol2tp_session_create() and hasn't been plugged
to a pppol2tp socket yet. That'd prevent session free because the extra
reference taken by pppol2tp_session_close() wouldn't be dropped by the
socket's ->sk_destruct() callback (pppol2tp_session_destruct()).
We could set .session_close() only while connecting a session to its
pppol2tp socket, or teach pppol2tp_session_close() to avoid grabbing a
reference when the session isn't connected, but that'd require adding
some form of synchronisation to be race free.

Instead of that, we can just let the pppol2tp socket hold a reference
on the session as soon as it starts depending on it (that is, in
pppol2tp_connect()). Then we don't need to utilise
pppol2tp_session_close() to hold a reference at the last moment to
prevent l2tp_core from dropping it.

When releasing the socket, pppol2tp_release() now deletes the session
using the standard l2tp_session_delete() function, instead of merely
removing it from hash tables. l2tp_session_delete() drops the reference
the sessions holds on itself, but also makes sure it doesn't remove a
session twice. So it can safely be called, even if l2tp_core already
tried, or is concurrently trying, to remove the session.
Finally, pppol2tp_session_destruct() drops the reference held by the
socket.

Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-29 11:16:22 +09:00
Guillaume Nault
ee40fb2e1e l2tp: protect sock pointer of struct pppol2tp_session with RCU
pppol2tp_session_create() registers sessions that can't have their
corresponding socket initialised. This socket has to be created by
userspace, then connected to the session by pppol2tp_connect().
Therefore, we need to protect the pppol2tp socket pointer of L2TP
sessions, so that it can safely be updated when userspace is connecting
or closing the socket. This will eventually allow pppol2tp_connect()
to avoid generating transient states while initialising its parts of the
session.

To this end, this patch protects the pppol2tp socket pointer using RCU.

The pppol2tp socket pointer is still set in pppol2tp_connect(), but
only once we know the function isn't going to fail. It's eventually
reset by pppol2tp_release(), which now has to wait for a grace period
to elapse before it can drop the last reference on the socket. This
ensures that pppol2tp_session_get_sock() can safely grab a reference
on the socket, even after ps->sk is reset to NULL but before this
operation actually gets visible from pppol2tp_session_get_sock().

The rest is standard RCU conversion: pppol2tp_recv(), which already
runs in atomic context, is simply enclosed by rcu_read_lock() and
rcu_read_unlock(), while other functions are converted to use
pppol2tp_session_get_sock() followed by sock_put().
pppol2tp_session_setsockopt() is a special case. It used to retrieve
the pppol2tp socket from the L2TP session, which itself was retrieved
from the pppol2tp socket. Therefore we can just avoid dereferencing
ps->sk and directly use the original socket pointer instead.

With all users of ps->sk now handling NULL and concurrent updates, the
L2TP ->ref() and ->deref() callbacks aren't needed anymore. Therefore,
rather than converting pppol2tp_session_sock_hold() and
pppol2tp_session_sock_put(), we can just drop them.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-29 11:16:22 +09:00
Guillaume Nault
3953ae7b21 l2tp: don't register sessions in l2tp_session_create()
Sessions created by l2tp_session_create() aren't fully initialised:
some pseudo-wire specific operations need to be done before making the
session usable. Therefore the PPP and Ethernet pseudo-wires continue
working on the returned l2tp session while it's already been exposed to
the rest of the system.
This can lead to various issues. In particular, the session may enter
the deletion process before having been fully initialised, which will
confuse the session removal code.

This patch moves session registration out of l2tp_session_create(), so
that callers can control when the session is exposed to the rest of the
system. This is done by the new l2tp_session_register() function.

Only pppol2tp_session_create() can be easily converted to avoid
modifying its session after registration (the debug message is dropped
in order to avoid the need for holding a reference on the session).

For pppol2tp_connect() and l2tp_eth_create()), more work is needed.
That'll be done in followup patches. For now, let's just register the
session right after its creation, like it was done before. The only
difference is that we can easily take a reference on the session before
registering it, so, at least, we're sure it's not going to be freed
while we're working on it.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-29 11:16:21 +09:00
Guillaume Nault
5903f59493 l2tp: check ps->sock before running pppol2tp_session_ioctl()
When pppol2tp_session_ioctl() is called by pppol2tp_tunnel_ioctl(),
the session may be unconnected. That is, it was created by
pppol2tp_session_create() and hasn't been connected with
pppol2tp_connect(). In this case, ps->sock is NULL, so we need to check
for this case in order to avoid dereferencing a NULL pointer.

Fixes: 309795f4be ("l2tp: Add netlink control API for L2TP")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-14 18:38:56 -07:00
Guillaume Nault
cdd10c9627 l2tp: ensure sessions are freed after their PPPOL2TP socket
If l2tp_tunnel_delete() or l2tp_tunnel_closeall() deletes a session
right after pppol2tp_release() orphaned its socket, then the 'sock'
variable of the pppol2tp_session_close() callback is NULL. Yet the
session is still used by pppol2tp_release().

Therefore we need to take an extra reference in any case, to prevent
l2tp_tunnel_delete() or l2tp_tunnel_closeall() from freeing the session.

Since the pppol2tp_session_close() callback is only set if the session
is associated to a PPPOL2TP socket and that both l2tp_tunnel_delete()
and l2tp_tunnel_closeall() hold the PPPOL2TP socket before calling
pppol2tp_session_close(), we're sure that pppol2tp_session_close() and
pppol2tp_session_destruct() are paired and called in the right order.
So the reference taken by the former will be released by the later.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-25 14:44:41 -07:00
Guillaume Nault
f026bc29a8 l2tp: pass tunnel pointer to ->session_create()
Using l2tp_tunnel_find() in pppol2tp_session_create() and
l2tp_eth_create() is racy, because no reference is held on the
returned session. These functions are only used to implement the
->session_create callback which is run by l2tp_nl_cmd_session_create().
Therefore searching for the parent tunnel isn't necessary because
l2tp_nl_cmd_session_create() already has a pointer to it and holds a
reference.

This patch modifies ->session_create()'s prototype to directly pass the
the parent tunnel as parameter, thus avoiding searching for it in
pppol2tp_session_create() and l2tp_eth_create().

Since we have to touch the ->session_create() call in
l2tp_nl_cmd_session_create(), let's also remove the useless conditional:
we know that ->session_create isn't NULL at this point because it's
already been checked earlier in this same function.

Finally, one might be tempted to think that the removed
l2tp_tunnel_find() calls were harmless because they would return the
same tunnel as the one held by l2tp_nl_cmd_session_create() anyway.
But that tunnel might be removed and a new one created with same tunnel
Id before the l2tp_tunnel_find() call. In this case l2tp_tunnel_find()
would return the new tunnel which wouldn't be protected by the
reference held by l2tp_nl_cmd_session_create().

Fixes: 309795f4be ("l2tp: Add netlink control API for L2TP")
Fixes: d9e31d17ce ("l2tp: Add L2TP ethernet pseudowire support")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-03 11:04:21 -07:00
Reshetova, Elena
fbea9e0760 net, l2tp: convert l2tp_tunnel.ref_count from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-04 22:35:15 +01:00
Guillaume Nault
321a52a391 l2tp: don't mask errors in pppol2tp_getsockopt()
pppol2tp_getsockopt() doesn't take into account the error code returned
by pppol2tp_tunnel_getsockopt() or pppol2tp_session_getsockopt(). If
error occurs there, pppol2tp_getsockopt() continues unconditionally and
reports erroneous values.

Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-08 08:29:04 -07:00
Guillaume Nault
364700cf8f l2tp: don't mask errors in pppol2tp_setsockopt()
pppol2tp_setsockopt() unconditionally overwrites the error value
returned by pppol2tp_tunnel_setsockopt() or
pppol2tp_session_setsockopt(), thus hiding errors from userspace.

Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-08 08:29:04 -07:00
Guillaume Nault
249ee819e2 l2tp: fix PPP pseudo-wire auto-loading
PPP pseudo-wire type is 7 (11 is L2TP_PWTYPE_IP).

Fixes: f1f39f9110 ("l2tp: auto load type modules")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-04 10:08:42 -07:00
Guillaume Nault
e08293a4cc l2tp: take reference on sessions being dumped
Take a reference on the sessions returned by l2tp_session_find_nth()
(and rename it l2tp_session_get_nth() to reflect this change), so that
caller is assured that the session isn't going to disappear while
processing it.

For procfs and debugfs handlers, the session is held in the .start()
callback and dropped in .show(). Given that pppol2tp_seq_session_show()
dereferences the associated PPPoL2TP socket and that
l2tp_dfs_seq_session_show() might call pppol2tp_show(), we also need to
call the session's .ref() callback to prevent the socket from going
away from under us.

Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Fixes: 0ad6614048 ("l2tp: Add debugfs files for dumping l2tp debug info")
Fixes: 309795f4be ("l2tp: Add netlink control API for L2TP")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-04 10:00:56 -07:00
Guillaume Nault
dbdbc73b44 l2tp: fix duplicate session creation
l2tp_session_create() relies on its caller for checking for duplicate
sessions. This is racy since a session can be concurrently inserted
after the caller's verification.

Fix this by letting l2tp_session_create() verify sessions uniqueness
upon insertion. Callers need to be adapted to check for
l2tp_session_create()'s return code instead of calling
l2tp_session_find().

pppol2tp_connect() is a bit special because it has to work on existing
sessions (if they're not connected) or to create a new session if none
is found. When acting on a preexisting session, a reference must be
held or it could go away on us. So we have to use l2tp_session_get()
instead of l2tp_session_find() and drop the reference before exiting.

Fixes: d9e31d17ce ("l2tp: Add L2TP ethernet pseudowire support")
Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-01 20:16:41 -07:00
Guillaume Nault
57377d6354 l2tp: ensure session can't get removed during pppol2tp_session_ioctl()
Holding a reference on session is required before calling
pppol2tp_session_ioctl(). The session could get freed while processing the
ioctl otherwise. Since pppol2tp_session_ioctl() uses the session's socket,
we also need to take a reference on it in l2tp_session_get().

Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-01 20:16:41 -07:00
Guillaume Nault
e91793bb61 l2tp: purge socket queues in the .destruct() callback
The Rx path may grab the socket right before pppol2tp_release(), but
nothing guarantees that it will enqueue packets before
skb_queue_purge(). Therefore, the socket can be destroyed without its
queues fully purged.

Fix this by purging queues in pppol2tp_session_destruct() where we're
guaranteed nothing is still referencing the socket.

Fixes: 9e9cb6221a ("l2tp: fix userspace reception on plain L2TP sockets")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-29 09:26:28 -07:00
Asbjørn Sloth Tønnesen
fba40c632c net: l2tp: ppp: change PPPOL2TP_MSG_* => L2TP_MSG_*
Signed-off-by: Asbjoern Sloth Toennesen <asbjorn@asbjorn.st>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-10 23:29:11 -05:00
Asbjørn Sloth Tønnesen
3f9b9770b4 net: l2tp: fix negative assignment to unsigned int
recv_seq, send_seq and lns_mode mode are all defined as
unsigned int foo:1;

Signed-off-by: Asbjoern Sloth Toennesen <asbjorn@asbjorn.st>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-09 18:55:36 -05:00
Javier Martinez Canillas
9dd79945b0 l2tp: use IS_ENABLED() instead of checking for built-in or module
The IS_ENABLED() macro checks if a Kconfig symbol has been enabled either
built-in or as a module, use that macro instead of open coding the same.

Using the macro makes the code more readable by helping abstract away some
of the Kconfig built-in and module enable details.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-10 21:19:11 -07:00
David S. Miller
6abdd5f593 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
All three conflicts were cases of simple overlapping
changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-30 00:54:02 -04:00