linux-stable.git/net/ipv4, branch v3.18.22

inet: frags: fix defragmented packet's IP header for af_packet

2015-09-28T22:57:01+00:00

[ Upstream commit 0848f6428ba3a2e42db124d41ac6f548655735bf ]

When ip_frag_queue() computes positions, it assumes that the passed
sk_buff does not contain L2 headers.

However, when PACKET_FANOUT_FLAG_DEFRAG is used, IP reassembly
functions can be called on outgoing packets that contain L2 headers.

Also, IPv4 checksum is not corrected after reassembly.

Fixes: 7736d33f4262 ("packet: Add pre-defragmentation support for ipv4 fanouts.")
Signed-off-by: Edward Hyunkoo Jee 
Signed-off-by: Eric Dumazet 
Cc: Willem de Bruijn 
Cc: Jerry Chu 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ipv6: lock socket in ip6_datagram_connect()

2015-09-28T22:57:01+00:00

[ Upstream commit 03645a11a570d52e70631838cb786eb4253eb463 ]

ip6_datagram_connect() is doing a lot of socket changes without
socket being locked.

This looks wrong, at least for udp_lib_rehash() which could corrupt
lists because of concurrent udp_sk(sk)->udp_portaddr_hash accesses.

Signed-off-by: Eric Dumazet 
Acked-by: Herbert Xu 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ip_tunnel: fix ipv4 pmtu check to honor inner ip header df

2015-09-27T16:18:54+00:00

[ Upstream commit fc24f2b2094366da8786f59f2606307e934cea17 ]

Frag needed should be sent only if the inner header asked
to not fragment. Currently fragmentation is broken if the
tunnel has df set, but df was not asked in the original
packet. The tunnel's df needs to be still checked to update
internally the pmtu cache.

Commit 23a3647bc4f93bac broke it, and this commit fixes
the ipv4 df check back to the way it was.

Fixes: 23a3647bc4f93bac ("ip_tunnels: Use skb-len to PMTU check.")
Cc: Pravin B Shelar 
Signed-off-by: Timo Teräs 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ip_vti/ip6_vti: Preserve skb->mark after rcv_cb call

2015-08-27T17:26:14+00:00

[ Upstream commit d55c670cbc54b2270a465cdc382ce71adae45785 ]

The vti6_rcv_cb and vti_rcv_cb calls were leaving the skb->mark modified
after completing the function.  This resulted in the original skb->mark
value being lost.  Since we only need skb->mark to be set for
xfrm_policy_check we can pull the assignment into the rcv_cb calls and then
just restore the original mark after xfrm_policy_check has been completed.

Signed-off-by: Alexander Duyck 
Signed-off-by: Steffen Klassert 
Signed-off-by: Sasha Levin

ip_vti/ip6_vti: Do not touch skb->mark on xmit

2015-08-27T17:26:13+00:00

[ Upstream commit cd5279c194f89c9b97c294af4aaf4ea8c5e3c704 ]

Instead of modifying skb->mark we can simply modify the flowi_mark that is
generated as a result of the xfrm_decode_session.  By doing this we don't
need to actually touch the skb->mark and it can be preserved as it passes
out through the tunnel.

Signed-off-by: Alexander Duyck 
Signed-off-by: Steffen Klassert 
Signed-off-by: Sasha Levin

tcp: Do not call tcp_fastopen_reset_cipher from interrupt context

2015-07-05T14:12:59+00:00

[ Upstream commit dfea2aa654243f70dc53b8648d0bbdeec55a7df1 ]

tcp_fastopen_reset_cipher really cannot be called from interrupt
context. It allocates the tcp_fastopen_context with GFP_KERNEL and
calls crypto_alloc_cipher, which allocates all kind of stuff with
GFP_KERNEL.

Thus, we might sleep when the key-generation is triggered by an
incoming TFO cookie-request which would then happen in interrupt-
context, as shown by enabling CONFIG_DEBUG_ATOMIC_SLEEP:

[   36.001813] BUG: sleeping function called from invalid context at mm/slub.c:1266
[   36.003624] in_atomic(): 1, irqs_disabled(): 0, pid: 1016, name: packetdrill
[   36.004859] CPU: 1 PID: 1016 Comm: packetdrill Not tainted 4.1.0-rc7 #14
[   36.006085] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
[   36.008250]  00000000000004f2 ffff88007f8838a8 ffffffff8171d53a ffff880075a084a8
[   36.009630]  ffff880075a08000 ffff88007f8838c8 ffffffff810967d3 ffff88007f883928
[   36.011076]  0000000000000000 ffff88007f8838f8 ffffffff81096892 ffff88007f89be00
[   36.012494] Call Trace:
[   36.012953]    [] dump_stack+0x4f/0x6d
[   36.014085]  [] ___might_sleep+0x103/0x170
[   36.015117]  [] __might_sleep+0x52/0x90
[   36.016117]  [] kmem_cache_alloc_trace+0x47/0x190
[   36.017266]  [] ? tcp_fastopen_reset_cipher+0x42/0x130
[   36.018485]  [] tcp_fastopen_reset_cipher+0x42/0x130
[   36.019679]  [] tcp_fastopen_init_key_once+0x61/0x70
[   36.020884]  [] __tcp_fastopen_cookie_gen+0x1c/0x60
[   36.022058]  [] tcp_try_fastopen+0x58f/0x730
[   36.023118]  [] tcp_conn_request+0x3e8/0x7b0
[   36.024185]  [] ? __module_text_address+0x12/0x60
[   36.025327]  [] tcp_v4_conn_request+0x51/0x60
[   36.026410]  [] tcp_rcv_state_process+0x190/0xda0
[   36.027556]  [] ? __inet_lookup_established+0x47/0x170
[   36.028784]  [] tcp_v4_do_rcv+0x16d/0x3d0
[   36.029832]  [] ? security_sock_rcv_skb+0x16/0x20
[   36.030936]  [] tcp_v4_rcv+0x77a/0x7b0
[   36.031875]  [] ? iptable_filter_hook+0x33/0x70
[   36.032953]  [] ip_local_deliver_finish+0x92/0x1f0
[   36.034065]  [] ip_local_deliver+0x9a/0xb0
[   36.035069]  [] ? ip_rcv+0x3d0/0x3d0
[   36.035963]  [] ip_rcv_finish+0x119/0x330
[   36.036950]  [] ip_rcv+0x2e7/0x3d0
[   36.037847]  [] __netif_receive_skb_core+0x552/0x930
[   36.038994]  [] __netif_receive_skb+0x27/0x70
[   36.040033]  [] process_backlog+0xd2/0x1f0
[   36.041025]  [] net_rx_action+0x122/0x310
[   36.042007]  [] __do_softirq+0x103/0x2f0
[   36.042978]  [] do_softirq_own_stack+0x1c/0x30

This patch moves the call to tcp_fastopen_init_key_once to the places
where a listener socket creates its TFO-state, which always happens in
user-context (either from the setsockopt, or implicitly during the
listen()-call)

Cc: Eric Dumazet 
Cc: Hannes Frederic Sowa 
Fixes: 222e83d2e0ae ("tcp: switch tcp_fastopen key generation to net_get_random_once")
Signed-off-by: Christoph Paasch 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

tcp: tcp_get_info() should fetch socket fields once

2015-06-28T17:39:26+00:00

[ Upstream commit fad9dfefea6405039491e7e4fc21fb6e59e7d26c ]

tcp_get_info() can be called without holding socket lock,
so any socket fields can change under us.

Use READ_ONCE() to fetch sk_pacing_rate and sk_max_pacing_rate

Fixes: 977cb0ecf82e ("tcp: add pacing_rate information into tcp_info")
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ipv4/udp: Verify multicast group is ours in upd_v4_early_demux()

2015-06-15T18:26:54+00:00

[ Upstream commit 6e540309326188f769e03bb4c6dd8ff6752930c2 ]

421b3885bf6d56391297844f43fb7154a6396e12 "udp: ipv4: Add udp early
demux" introduced a regression that allowed sockets bound to INADDR_ANY
to receive packets from multicast groups that the socket had not joined.
For example a socket that had joined 224.168.2.9 could also receive
packets from 225.168.2.9 despite not having joined that group if
ip_early_demux is enabled.

Fix this by calling ip_check_mc_rcu() in udp_v4_early_demux() to verify
that the multicast packet is indeed ours.

Signed-off-by: Shawn Bohrer 
Reported-by: Yurij M. Plotnikov 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

tcp: fix child sockets to use system default congestion control if not set

2015-06-15T18:26:53+00:00

[ Upstream commit 9f950415e4e28e7cfae2e416b43e862e8101d996 ]

Linux 3.17 and earlier are explicitly engineered so that if the app
doesn't specifically request a CC module on a listener before the SYN
arrives, then the child gets the system default CC when the connection
is established. See tcp_init_congestion_control() in 3.17 or earlier,
which says "if no choice made yet assign the current value set as
default". The change ("net: tcp: assign tcp cong_ops when tcp sk is
created") altered these semantics, so that children got their parent
listener's congestion control even if the system default had changed
after the listener was created.

This commit returns to those original semantics from 3.17 and earlier,
since they are the original semantics from 2007 in 4d4d3d1e8 ("[TCP]:
Congestion control initialization."), and some Linux congestion
control workflows depend on that.

In summary, if a listener socket specifically sets TCP_CONGESTION to
"x", or the route locks the CC module to "x", then the child gets
"x". Otherwise the child gets current system default from
net.ipv4.tcp_congestion_control. That's the behavior in 3.17 and
earlier, and this commit restores that.

Fixes: 55d8694fa82c ("net: tcp: assign tcp cong_ops when tcp sk is created")
Cc: Florian Westphal 
Cc: Daniel Borkmann 
Cc: Glenn Judd 
Cc: Stephen Hemminger 
Signed-off-by: Neal Cardwell 
Signed-off-by: Eric Dumazet 
Signed-off-by: Yuchung Cheng 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

udp: fix behavior of wrong checksums

2015-06-15T18:26:53+00:00

[ Upstream commit beb39db59d14990e401e235faf66a6b9b31240b0 ]

We have two problems in UDP stack related to bogus checksums :

1) We return -EAGAIN to application even if receive queue is not empty.
   This breaks applications using edge trigger epoll()

2) Under UDP flood, we can loop forever without yielding to other
   processes, potentially hanging the host, especially on non SMP.

This patch is an attempt to make things better.

We might in the future add extra support for rt applications
wanting to better control time spent doing a recv() in a hostile
environment. For example we could validate checksums before queuing
packets in socket receive queue.

Signed-off-by: Eric Dumazet 
Cc: Willem de Bruijn 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin