linux-stable.git/net/ipv4, branch v4.9.95

route: check sysctl_fib_multipath_use_neigh earlier than hash

2018-04-13T17:48:36+00:00

[ Upstream commit 6174a30df1b902e1fedbd728f5343937e83e64e6 ]

Prior to this patch, when one packet is hashed into path [1]
(hash <= nh_upper_bound) and it's neigh is dead, it will try
path [2]. However, if path [2]'s neigh is alive but it's
hash > nh_upper_bound, it will not return this alive path.
This packet will never be sent even if path [2] is alive.

 3.3.3.1/24:
  nexthop via 1.1.1.254 dev eth1 weight 1 <--[1] (dead neigh)
  nexthop via 2.2.2.254 dev eth2 weight 1 <--[2]

With sysctl_fib_multipath_use_neigh set is supposed to find an
available path respecting to the l3/l4 hash. But if there is
no available route with this hash, it should at least return
an alive route even with other hash.

This patch is to fix it by processing fib_multipath_use_neigh
earlier than the hash check, so that it will at least return
an alive route if there is when fib_multipath_use_neigh is
enabled. It's also compatible with before when there are alive
routes with the l3/l4 hash.

Fixes: a6db4494d218 ("net: ipv4: Consider failed nexthops in multipath routes")
Reported-by: Jianlin Shi 
Signed-off-by: Xin Long 
Acked-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ip_tunnel: better validate user provided tunnel names

2018-04-13T17:48:34+00:00

[ Upstream commit 9cb726a212a82c88c98aa9f0037fd04777cd8fe5 ]

Use dev_valid_name() to make sure user does not provide illegal
device name.

syzbot caught the following bug :

BUG: KASAN: stack-out-of-bounds in strlcpy include/linux/string.h:300 [inline]
BUG: KASAN: stack-out-of-bounds in __ip_tunnel_create+0xca/0x6b0 net/ipv4/ip_tunnel.c:257
Write of size 20 at addr ffff8801ac79f810 by task syzkaller268107/4482

CPU: 0 PID: 4482 Comm: syzkaller268107 Not tainted 4.16.0+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b9/0x29f lib/dump_stack.c:53
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0xac/0x2f5 mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 memcpy+0x37/0x50 mm/kasan/kasan.c:303
 strlcpy include/linux/string.h:300 [inline]
 __ip_tunnel_create+0xca/0x6b0 net/ipv4/ip_tunnel.c:257
 ip_tunnel_create net/ipv4/ip_tunnel.c:352 [inline]
 ip_tunnel_ioctl+0x818/0xd40 net/ipv4/ip_tunnel.c:861
 ipip_tunnel_ioctl+0x1c5/0x420 net/ipv4/ipip.c:350
 dev_ifsioc+0x43e/0xb90 net/core/dev_ioctl.c:334
 dev_ioctl+0x69a/0xcc0 net/core/dev_ioctl.c:525
 sock_ioctl+0x47e/0x680 net/socket.c:1015
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1cf/0x1650 fs/ioctl.c:684
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
 SYSC_ioctl fs/ioctl.c:708 [inline]
 SyS_ioctl+0x24/0x30 fs/ioctl.c:706
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

arp: fix arp_filter on l3slave devices

2018-04-13T17:48:32+00:00

[ Upstream commit 58b35f27689b5eb514fc293c332966c226b1b6e4 ]

arp_filter performs an ip_route_output search for arp source address and
checks if output device is the same where the arp request was received,
if it is not, the arp request is not answered.

This route lookup is always done on main route table so l3slave devices
never find the proper route and arp is not answered.

Passing l3mdev_master_ifindex_rcu(dev) return value as oif fixes the
lookup for l3slave devices while maintaining same behavior for non
l3slave devices as this function returns 0 in that case.

Fixes: 613d09b30f8b ("net: Use VRF device index for lookups on TX")
Signed-off-by: Miguel Fadon Perlines 
Acked-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipsec: check return value of skb_to_sgvec always

2018-04-13T17:48:31+00:00

commit 3f29770723fe498a5c5f57c3a31a996ebdde03e1 upstream.

Signed-off-by: Jason A. Donenfeld 
Cc: Steffen Klassert 
Cc: Herbert Xu 
Cc: "David S. Miller" 
Signed-off-by: David S. Miller 
[natechancellor: Adjusted context due to lack of fca11ebde3f0]
Signed-off-by: Nathan Chancellor 
Signed-off-by: Greg Kroah-Hartman

tcp: better validation of received ack sequences

2018-04-13T17:48:06+00:00

[ Upstream commit d0e1a1b5a833b625c93d3d49847609350ebd79db ]

Paul Fiterau Brostean reported :


Linux TCP stack we analyze exhibits behavior that seems odd to me.
The scenario is as follows (all packets have empty payloads, no window
scaling, rcv/snd window size should not be a factor):

       TEST HARNESS (CLIENT)                        LINUX SERVER

   1.  -                                          LISTEN (server listen,
then accepts)

   2.  - -->                --> SYN-RECEIVED

   3.  - <--   <-- SYN-RECEIVED

   4.  - -->       --> ESTABLISHED

   5.  - <--   <-- FIN WAIT-1 (server
opts to close the data connection calling "close" on the connection
socket)

   6.  - -->  --> CLOSING (client sends
FIN,ACK with not yet sent acknowledgement number)

   7.  - <--       <-- CLOSING (ACK is 102
instead of 101, why?)

... (silence from CLIENT)

   8.  - <--   <-- CLOSING
(retransmission, again ACK is 102)

Now, note that packet 6 while having the expected sequence number,
acknowledges something that wasn't sent by the server. So I would
expect
the packet to maybe prompt an ACK response from the server, and then be
ignored. Yet it is not ignored and actually leads to an increase of the
acknowledgement number in the server's retransmission of the FIN,ACK
packet. The explanation I found is that the FIN  in packet 6 was
processed, despite the acknowledgement number being unacceptable.
Further experiments indeed show that the server processes this FIN,
transitioning to CLOSING, then on receiving an ACK for the FIN it had
send in packet 5, the server (or better said connection) transitions
from CLOSING to TIME_WAIT (as signaled by netstat).



Indeed, tcp_rcv_state_process() calls tcp_ack() but
does not exploit the @acceptable status but for TCP_SYN_RECV
state.

What we want here is to send a challenge ACK, if not in TCP_SYN_RECV
state. TCP_FIN_WAIT1 state is not the only state we should fix.

Add a FLAG_NO_CHALLENGE_ACK so that tcp_rcv_state_process()
can choose to send a challenge ACK and discard the packet instead
of wrongly change socket state.

With help from Neal Cardwell.

Signed-off-by: Eric Dumazet 
Reported-by: Paul Fiterau Brostean 
Cc: Neal Cardwell 
Cc: Yuchung Cheng 
Cc: Soheil Hassas Yeganeh 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

arp: honour gratuitous ARP _replies_

2018-04-13T17:47:59+00:00

[ Upstream commit 23d268eb240954e6e78f7cfab04f2b1e79f84489 ]

When arp_accept is 1, gratuitous ARPs are supposed to override matching
entries irrespective of whether they arrive during locktime. This was
implemented in commit 56022a8fdd87 ("ipv4: arp: update neighbour address
when a gratuitous arp is received and arp_accept is set")

There is a glitch in the patch though. RFC 2002, section 4.6, "ARP,
Proxy ARP, and Gratuitous ARP", defines gratuitous ARPs so that they can
be either of Request or Reply type. Those Reply gratuitous ARPs can be
triggered with standard tooling, for example, arping -A option does just
that.

This patch fixes the glitch, making both Request and Reply flavours of
gratuitous ARPs to behave identically.

As per RFC, if gratuitous ARPs are of Reply type, their Target Hardware
Address field should also be set to the link-layer address to which this
cache entry should be updated. The field is present in ARP over Ethernet
but not in IEEE 1394. In this patch, I don't consider any broadcasted
ARP replies as gratuitous if the field is not present, to conform the
standard. It's not clear whether there is such a thing for IEEE 1394 as
a gratuitous ARP reply; until it's cleared up, we will ignore such
broadcasts. Note that they will still update existing ARP cache entries,
assuming they arrive out of locktime time interval.

Signed-off-by: Ihar Hrachyshka 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ipmr: vrf: Find VIFs using the actual device

2018-04-13T17:47:59+00:00

[ Upstream commit bcfc7d33110b0f33069d74138eeb7ca9acbb3c85 ]

The skb->dev that is passed into ip_mr_input is
the loX device for VRFs. When we lookup a vif
for this dev, none is found as we do not create
vifs for loopbacks. Instead lookup a vif for the
actual device that the packet was received on,
eg the vlan.

Signed-off-by: Thomas Winter 
cc: David Ahern 
cc: Nikolay Aleksandrov 
cc: roopa 
Acked-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_nat_h323: fix logical-not-parentheses warning

2018-04-08T10:12:44+00:00

commit eee6ebbac18a189ef33d25ea9b8bcae176515e49 upstream.

Clang produces the following warning:

net/ipv4/netfilter/nf_nat_h323.c:553:6: error:
logical not is only applied to the left hand side of this comparison
  [-Werror,-Wlogical-not-parentheses]
if (!set_h225_addr(skb, protoff, data, dataoff, taddr,
    ^
add parentheses after the '!' to evaluate the comparison first
add parentheses around left hand side expression to silence this warning

There's not necessarily a bug here, but it's cleaner to return early,
ex:

if (x)
  return
...

rather than:

if (x == 0)
  ...
else
  return

Also added a return code check that seemed to be missing in one
instance.

Signed-off-by: Nick Desaulniers 
Signed-off-by: Pablo Neira Ayuso 
Cc: Nathan Chancellor 
Signed-off-by: Greg Kroah-Hartman

net: Only honor ifindex in IP_PKTINFO if non-0

2018-03-31T16:11:34+00:00

[ Upstream commit 2cbb4ea7de167b02ffa63e9cdfdb07a7e7094615 ]

Only allow ifindex from IP_PKTINFO to override SO_BINDTODEVICE settings
if the index is actually set in the message.

Signed-off-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: Fix hlist corruptions in inet_evict_bucket()

2018-03-31T16:11:33+00:00

[ Upstream commit a560002437d3646dafccecb1bf32d1685112ddda ]

inet_evict_bucket() iterates global list, and
several tasks may call it in parallel. All of
them hash the same fq->list_evictor to different
lists, which leads to list corruption.

This patch makes fq be hashed to expired list
only if this has not been made yet by another
task. Since inet_frag_alloc() allocates fq
using kmem_cache_zalloc(), we may rely on
list_evictor is initially unhashed.

The problem seems to exist before async
pernet_operations, as there was possible to have
exit method to be executed in parallel with
inet_frags::frags_work, so I add two Fixes tags.
This also may go to stable.

Fixes: d1fe19444d82 "inet: frag: don't re-use chainlist for evictor"
Fixes: f84c6821aa54 "net: Convert pernet_subsys, registered from inet_init()"
Signed-off-by: Kirill Tkhai 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman