linux-stable.git/net/openvswitch, branch v4.9.170

openvswitch: fix flow actions reallocation

2019-04-17T06:36:44+00:00

[ Upstream commit f28cd2af22a0c134e4aa1c64a70f70d815d473fb ]

The flow action buffer can be resized if it's not big enough to contain
all the requested flow actions. However, this resize doesn't take into
account the new requested size, the buffer is only increased by a factor
of 2x. This might be not enough to contain the new data, causing a
buffer overflow, for example:

[   42.044472] =============================================================================
[   42.045608] BUG kmalloc-96 (Not tainted): Redzone overwritten
[   42.046415] -----------------------------------------------------------------------------

[   42.047715] Disabling lock debugging due to kernel taint
[   42.047716] INFO: 0x8bf2c4a5-0x720c0928. First byte 0x0 instead of 0xcc
[   42.048677] INFO: Slab 0xbc6d2040 objects=29 used=18 fp=0xdc07dec4 flags=0x2808101
[   42.049743] INFO: Object 0xd53a3464 @offset=2528 fp=0xccdcdebb

[   42.050747] Redzone 76f1b237: cc cc cc cc cc cc cc cc                          ........
[   42.051839] Object d53a3464: 6b 6b 6b 6b 6b 6b 6b 6b 0c 00 00 00 6c 00 00 00  kkkkkkkk....l...
[   42.053015] Object f49a30cc: 6c 00 0c 00 00 00 00 00 00 00 00 03 78 a3 15 f6  l...........x...
[   42.054203] Object acfe4220: 20 00 02 00 ff ff ff ff 00 00 00 00 00 00 00 00   ...............
[   42.055370] Object 21024e91: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[   42.056541] Object 070e04c3: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[   42.057797] Object 948a777a: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[   42.059061] Redzone 8bf2c4a5: 00 00 00 00                                      ....
[   42.060189] Padding a681b46e: 5a 5a 5a 5a 5a 5a 5a 5a                          ZZZZZZZZ

Fix by making sure the new buffer is properly resized to contain all the
requested data.

BugLink: https://bugs.launchpad.net/bugs/1813244
Signed-off-by: Andrea Righi 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

openvswitch: Avoid OOB read when parsing flow nlattrs

2019-01-31T07:12:33+00:00

[ Upstream commit 04a4af334b971814eedf4e4a413343ad3287d9a9 ]

For nested and variable attributes, the expected length of an attribute
is not known and marked by a negative number.  This results in an OOB
read when the expected length is later used to check if the attribute is
all zeros. Fix this by using the actual length of the attribute rather
than the expected length.

Signed-off-by: Ross Lagerwall 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

openvswitch: Remove padding from packet before L3+ conntrack processing

2018-05-30T05:50:23+00:00

[ Upstream commit 9382fe71c0058465e942a633869629929102843d ]

IPv4 and IPv6 packets may arrive with lower-layer padding that is not
included in the L3 length. For example, a short IPv4 packet may have
up to 6 bytes of padding following the IP payload when received on an
Ethernet device with a minimum packet length of 64 bytes.

Higher-layer processing functions in netfilter (e.g. nf_ip_checksum(),
and help() in nf_conntrack_ftp) assume skb->len reflects the length of
the L3 header and payload, rather than referring back to
ip_hdr->tot_len or ipv6_hdr->payload_len, and get confused by
lower-layer padding.

In the normal IPv4 receive path, ip_rcv() trims the packet to
ip_hdr->tot_len before invoking netfilter hooks. In the IPv6 receive
path, ip6_rcv() does the same using ipv6_hdr->payload_len. Similarly
in the br_netfilter receive path, br_validate_ipv4() and
br_validate_ipv6() trim the packet to the L3 length before invoking
netfilter hooks.

Currently in the OVS conntrack receive path, ovs_ct_execute() pulls
the skb to the L3 header but does not trim it to the L3 length before
calling nf_conntrack_in(NF_INET_PRE_ROUTING). When
nf_conntrack_proto_tcp encounters a packet with lower-layer padding,
nf_ip_checksum() fails causing a "nf_ct_tcp: bad TCP checksum" log
message. While extra zero bytes don't affect the checksum, the length
in the IP pseudoheader does. That length is based on skb->len, and
without trimming, it doesn't match the length the sender used when
computing the checksum.

In ovs_ct_execute(), trim the skb to the L3 length before higher-layer
processing.

Signed-off-by: Ed Swierk 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

openvswitch: Don't swap table in nlattr_set() after OVS_ATTR_NESTED is found

2018-05-19T08:26:58+00:00

[ Upstream commit 72f17baf2352ded6a1d3f4bb2d15da8c678cd2cb ]

If an OVS_ATTR_NESTED attribute type is found while walking
through netlink attributes, we call nlattr_set() recursively
passing the length table for the following nested attributes, if
different from the current one.

However, once we're done with those sub-nested attributes, we
should continue walking through attributes using the current
table, instead of using the one related to the sub-nested
attributes.

For example, given this sequence:

1  OVS_KEY_ATTR_PRIORITY
2  OVS_KEY_ATTR_TUNNEL
3	OVS_TUNNEL_KEY_ATTR_ID
4	OVS_TUNNEL_KEY_ATTR_IPV4_SRC
5	OVS_TUNNEL_KEY_ATTR_IPV4_DST
6	OVS_TUNNEL_KEY_ATTR_TTL
7	OVS_TUNNEL_KEY_ATTR_TP_SRC
8	OVS_TUNNEL_KEY_ATTR_TP_DST
9  OVS_KEY_ATTR_IN_PORT
10 OVS_KEY_ATTR_SKB_MARK
11 OVS_KEY_ATTR_MPLS

we switch to the 'ovs_tunnel_key_lens' table on attribute #3,
and we don't switch back to 'ovs_key_lens' while setting
attributes #9 to #11 in the sequence. As OVS_KEY_ATTR_MPLS
evaluates to 21, and the array size of 'ovs_tunnel_key_lens' is
15, we also get this kind of KASan splat while accessing the
wrong table:

[ 7654.586496] ==================================================================
[ 7654.594573] BUG: KASAN: global-out-of-bounds in nlattr_set+0x164/0xde9 [openvswitch]
[ 7654.603214] Read of size 4 at addr ffffffffc169ecf0 by task handler29/87430
[ 7654.610983]
[ 7654.612644] CPU: 21 PID: 87430 Comm: handler29 Kdump: loaded Not tainted 3.10.0-866.el7.test.x86_64 #1
[ 7654.623030] Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.1.7 06/16/2016
[ 7654.631379] Call Trace:
[ 7654.634108]  [] dump_stack+0x19/0x1b
[ 7654.639843]  [] print_address_description+0x33/0x290
[ 7654.647129]  [] ? nlattr_set+0x164/0xde9 [openvswitch]
[ 7654.654607]  [] kasan_report.part.3+0x242/0x330
[ 7654.661406]  [] __asan_report_load4_noabort+0x34/0x40
[ 7654.668789]  [] nlattr_set+0x164/0xde9 [openvswitch]
[ 7654.676076]  [] ovs_nla_get_match+0x10c8/0x1900 [openvswitch]
[ 7654.684234]  [] ? genl_rcv+0x28/0x40
[ 7654.689968]  [] ? netlink_unicast+0x3f3/0x590
[ 7654.696574]  [] ? ovs_nla_put_tunnel_info+0xb0/0xb0 [openvswitch]
[ 7654.705122]  [] ? unwind_get_return_address+0xb0/0xb0
[ 7654.712503]  [] ? system_call_fastpath+0x1c/0x21
[ 7654.719401]  [] ? update_stack_state+0x229/0x370
[ 7654.726298]  [] ? update_stack_state+0x229/0x370
[ 7654.733195]  [] ? kasan_unpoison_shadow+0x35/0x50
[ 7654.740187]  [] ? kasan_kmalloc+0xaa/0xe0
[ 7654.746406]  [] ? kasan_slab_alloc+0x12/0x20
[ 7654.752914]  [] ? memset+0x31/0x40
[ 7654.758456]  [] ovs_flow_cmd_new+0x2b2/0xf00 [openvswitch]

[snip]

[ 7655.132484] The buggy address belongs to the variable:
[ 7655.138226]  ovs_tunnel_key_lens+0xf0/0xffffffffffffd400 [openvswitch]
[ 7655.145507]
[ 7655.147166] Memory state around the buggy address:
[ 7655.152514]  ffffffffc169eb80: 00 00 00 00 00 00 00 00 00 00 fa fa fa fa fa fa
[ 7655.160585]  ffffffffc169ec00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 7655.168644] >ffffffffc169ec80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fa fa
[ 7655.176701]                                                              ^
[ 7655.184372]  ffffffffc169ed00: fa fa fa fa 00 00 00 00 fa fa fa fa 00 00 00 05
[ 7655.192431]  ffffffffc169ed80: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00
[ 7655.200490] ==================================================================

Reported-by: Hangbin Liu 
Fixes: 982b52700482 ("openvswitch: Fix mask generation for nested attributes.")
Signed-off-by: Stefano Brivio 
Reviewed-by: Sabrina Dubroca 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

openvswitch: Delete conntrack entry clashing with an expectation.

2018-03-24T10:00:14+00:00

[ Upstream commit cf5d70918877c6a6655dc1e92e2ebb661ce904fd ]

Conntrack helpers do not check for a potentially clashing conntrack
entry when creating a new expectation.  Also, nf_conntrack_in() will
check expectations (via init_conntrack()) only if a conntrack entry
can not be found.  The expectation for a packet which also matches an
existing conntrack entry will not be removed by conntrack, and is
currently handled inconsistently by OVS, as OVS expects the
expectation to be removed when the connection tracking entry matching
that expectation is confirmed.

It should be noted that normally an IP stack would not allow reuse of
a 5-tuple of an old (possibly lingering) connection for a new data
connection, so this is somewhat unlikely corner case.  However, it is
possible that a misbehaving source could cause conntrack entries be
created that could then interfere with new related connections.

Fix this in the OVS module by deleting the clashing conntrack entry
after an expectation has been matched.  This causes the following
nf_conntrack_in() call also find the expectation and remove it when
creating the new conntrack entry, as well as the forthcoming reply
direction packets to match the new related connection instead of the
old clashing conntrack entry.

Fixes: 7f8a436eaa2c ("openvswitch: Add conntrack action")
Reported-by: Yang Song 
Signed-off-by: Jarno Rajahalme 
Acked-by: Joe Stringer 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

openvswitch: fix the incorrect flow action alloc size

2018-02-03T16:05:37+00:00

[ Upstream commit 67c8d22a73128ff910e2287567132530abcf5b71 ]

If we want to add a datapath flow, which has more than 500 vxlan outputs'
action, we will get the following error reports:
  openvswitch: netlink: Flow action size 32832 bytes exceeds max
  openvswitch: netlink: Flow action size 32832 bytes exceeds max
  openvswitch: netlink: Actions may not be safe on all matching packets
  ... ...

It seems that we can simply enlarge the MAX_ACTIONS_BUFSIZE to fix it, but
this is not the root cause. For example, for a vxlan output action, we need
about 60 bytes for the nlattr, but after it is converted to the flow
action, it only occupies 24 bytes. This means that we can still support
more than 1000 vxlan output actions for a single datapath flow under the
the current 32k max limitation.

So even if the nla_len(attr) is larger than MAX_ACTIONS_BUFSIZE, we
shouldn't report EINVAL and keep it move on, as the judgement can be
done by the reserve_sfa_size.

Signed-off-by: zhangliping 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

openvswitch: fix skb_panic due to the incorrect actions attrlen

2017-08-30T08:21:40+00:00

[ Upstream commit 494bea39f3201776cdfddc232705f54a0bd210c4 ]

For sw_flow_actions, the actions_len only represents the kernel part's
size, and when we dump the actions to the userspace, we will do the
convertions, so it's true size may become bigger than the actions_len.

But unfortunately, for OVS_PACKET_ATTR_ACTIONS, we use the actions_len
to alloc the skbuff, so the user_skb's size may become insufficient and
oops will happen like this:
  skbuff: skb_over_panic: text:ffffffff8148fabf len:1749 put:157 head:
  ffff881300f39000 data:ffff881300f39000 tail:0x6d5 end:0x6c0 dev:
  ------------[ cut here ]------------
  kernel BUG at net/core/skbuff.c:129!
  [...]
  Call Trace:
   
   [] skb_put+0x43/0x44
   [] skb_zerocopy+0x6c/0x1f4
   [] queue_userspace_packet+0x3a3/0x448 [openvswitch]
   [] ovs_dp_upcall+0x30/0x5c [openvswitch]
   [] output_userspace+0x132/0x158 [openvswitch]
   [] ? ip6_rcv_finish+0x74/0x77 [ipv6]
   [] do_execute_actions+0xcc1/0xdc8 [openvswitch]
   [] ovs_execute_actions+0x74/0x106 [openvswitch]
   [] ovs_dp_process_packet+0xe1/0xfd [openvswitch]
   [] ? key_extract+0x63c/0x8d5 [openvswitch]
   [] ovs_vport_receive+0xa1/0xc3 [openvswitch]
  [...]

Also we can find that the actions_len is much little than the orig_len:
  crash> struct sw_flow_actions 0xffff8812f539d000
  struct sw_flow_actions {
    rcu = {
      next = 0xffff8812f5398800,
      func = 0xffffe3b00035db32
    },
    orig_len = 1384,
    actions_len = 592,
    actions = 0xffff8812f539d01c
  }

So as a quick fix, use the orig_len instead of the actions_len to alloc
the user_skb.

Last, this oops happened on our system running a relative old kernel, but
the same risk still exists on the mainline, since we use the wrong
actions_len from the beginning.

Fixes: ccea74457bbd ("openvswitch: include datapath actions with sampled-packet upcall to userspace")
Cc: Neil McKee 
Signed-off-by: Liping Zhang 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

openvswitch: fix potential out of bound access in parse_ct

2017-08-11T15:49:32+00:00

[ Upstream commit 69ec932e364b1ba9c3a2085fe96b76c8a3f71e7c ]

Before the 'type' is validated, we shouldn't use it to fetch the
ovs_ct_attr_lens's minlen and maxlen, else, out of bound access
may happen.

Fixes: 7f8a436eaa2c ("openvswitch: Add conntrack action")
Signed-off-by: Liping Zhang 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

openvswitch: Add missing case OVS_TUNNEL_KEY_ATTR_PAD

2017-03-30T07:41:21+00:00

[ Upstream commit 8f3dbfd79ed9ef9770305a7cc4e13dfd31ad2cd0 ]

Added a case for OVS_TUNNEL_KEY_ATTR_PAD to the switch statement
in ip_tun_from_nlattr in order to prevent the default case
returning an error.

Fixes: b46f6ded906e ("libnl: nla_put_be64(): align on a 64-bit area")
Signed-off-by: Kris Murphy 
Acked-by: Joe Stringer 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net/openvswitch: Set the ipv6 source tunnel key address attribute correctly

2017-03-30T07:41:20+00:00

[ Upstream commit 3d20f1f7bd575d147ffa75621fa560eea0aec690 ]

When dealing with ipv6 source tunnel key address attribute
(OVS_TUNNEL_KEY_ATTR_IPV6_SRC) we are wrongly setting the tunnel
dst ip, fix that.

Fixes: 6b26ba3a7d95 ('openvswitch: netlink attributes for IPv6 tunneling')
Signed-off-by: Or Gerlitz 
Reported-by: Paul Blakey 
Acked-by: Jiri Benc 
Acked-by: Joe Stringer 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman