linux-stable.git/drivers/net/ppp/pptp.c, branch linux-3.16.y

ipv4: hash net ptr into fragmentation bucket selection

2019-08-13T11:39:30+00:00

commit b6a7719aedd7e5c0f2df7641aa47386111682df4 upstream.

As namespaces are sometimes used with overlapping ip address ranges,
we should also use the namespace as input to the hash to select the ip
fragmentation counter bucket.

Cc: Eric Dumazet 
Cc: Flavio Leitner 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

pptp: dst_release sk_dst_cache in pptp_sock_destruct

2019-07-09T21:04:18+00:00

commit 9417d81f4f8adfe20a12dd1fadf73a618cbd945d upstream.

sk_setup_caps() is called to set sk->sk_dst_cache in pptp_connect,
so we have to dst_release(sk->sk_dst_cache) in pptp_sock_destruct,
otherwise, the dst refcnt will leak.

It can be reproduced by this syz log:

  r1 = socket$pptp(0x18, 0x1, 0x2)
  bind$pptp(r1, &(0x7f0000000100)={0x18, 0x2, {0x0, @local}}, 0x1e)
  connect$pptp(r1, &(0x7f0000000000)={0x18, 0x2, {0x3, @remote}}, 0x1e)

Consecutive dmesg warnings will occur:

  unregister_netdevice: waiting for lo to become free. Usage count = 1

v1->v2:
  - use rcu_dereference_protected() instead of rcu_dereference_check(),
    as suggested by Eric.

Fixes: 00959ade36ac ("PPTP: PPP over IPv4 (Point-to-Point Tunneling Protocol)")
Reported-by: Xiumei Mu 
Signed-off-by: Xin Long 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

pptp: fix illegal memory access caused by multiple bind()s

2016-02-25T10:50:58+00:00

commit 9a368aff9cb370298fa02feeffa861f2db497c18 upstream.

Several times already this has been reported as kasan reports caused by
syzkaller and trinity and people always looked at RCU races, but it is
much more simple. :)

In case we bind a pptp socket multiple times, we simply add it to
the callid_sock list but don't remove the old binding. Thus the old
socket stays in the bucket with unused call_id indexes and doesn't get
cleaned up. This causes various forms of kasan reports which were hard
to pinpoint.

Simply don't allow multiple binds and correct error handling in
pptp_bind. Also keep sk_state bits in place in pptp_connect.

Fixes: 00959ade36acad ("PPTP: PPP over IPv4 (Point-to-Point Tunneling Protocol)")
Cc: Dmitry Kozlov 
Cc: Sasha Levin 
Cc: Dmitry Vyukov 
Reported-by: Dmitry Vyukov 
Cc: Dave Jones 
Reported-by: Dave Jones 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
Signed-off-by: Luis Henriques

pptp: verify sockaddr_len in pptp_bind() and pptp_connect()

2016-01-04T17:20:47+00:00

commit 09ccfd238e5a0e670d8178cf50180ea81ae09ae1 upstream.

Reported-by: Dmitry Vyukov 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Luis Henriques

pptp: fix stack info leak in pptp_getname()

2014-12-01T10:02:10+00:00

commit a5f6fc28d6e6cc379c6839f21820e62262419584 upstream.

pptp_getname() only partially initializes the stack variable sa,
particularly only fills the pptp part of the sa_addr union. The code
thereby discloses 16 bytes of kernel stack memory via getsockname().

Fix this by memset(0)'ing the union before.

Cc: Dmitry Kozlov 
Signed-off-by: Mathias Krause 
Signed-off-by: David S. Miller 
Signed-off-by: Luis Henriques

inetpeer: get rid of ip_id_count

2014-06-02T18:00:41+00:00

Ideally, we would need to generate IP ID using a per destination IP
generator.

linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.

1) each inet_peer struct consumes 192 bytes

2) inetpeer cache uses a binary tree of inet_peer structs,
   with a nominal size of ~66000 elements under load.

3) lookups in this tree are hitting a lot of cache lines, as tree depth
   is about 20.

4) If server deals with many tcp flows, we have a high probability of
   not finding the inet_peer, allocating a fresh one, inserting it in
   the tree with same initial ip_id_count, (cf secure_ip_id())

5) We garbage collect inet_peer aggressively.

IP ID generation do not have to be 'perfect'

Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.

We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.

ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)

secure_ip_id() and secure_ipv6_id() no longer are needed.

Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

ip: generate unique IP identificator if local fragmentation is allowed

2013-09-19T18:11:15+00:00

If local fragmentation is allowed, then ip_select_ident() and
ip_select_ident_more() need to generate unique IDs to ensure
correct defragmentation on the peer.

For example, if IPsec (tunnel mode) has to encrypt large skbs
that have local_df bit set, then all IP fragments that belonged
to different ESP datagrams would have used the same identificator.
If one of these IP fragments would get lost or reordered, then
peer could possibly stitch together wrong IP fragments that did
not belong to the same datagram. This would lead to a packet loss
or data corruption.

Signed-off-by: Ansis Atteka 
Signed-off-by: David S. Miller

pptp: fix byte order warnings

2013-08-13T22:10:22+00:00

Pptp driver has lots of byte order warnings from sparse.
This was because the on-the-wire header is in network byte order (obviously)
but the definition did not reflect that.

Also, the address structure to user space actually put the call id
in host order. Rather than break ABI compatibility, just acknowledge
the existing design.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

pptp: fix sparse pointer warning

2013-08-09T21:14:50+00:00

callid_sock array is referenced via rcu_dereference and
sparse rcu checks complains about address space mismatch.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

pptp: lookup route with the proper net namespace

2012-08-08T22:57:10+00:00

pptp always use init_net as the net namespace to lookup
route, this will cause route lookup failed in container.

because we already set the correct net namespace to struct
sock in pptp_create,so fix this by using sock_net(sk) to
replace &init_net.

Signed-off-by: Gao feng 
Signed-off-by: David S. Miller