linux-stable.git/net/ipv4, branch v3.18.26

fou: clean up socket with kfree_rcu

2016-01-15T23:41:52+00:00

[ Upstream commit 3036facbb7be3a169e35be3b271162b0fa564a2d ]

fou->udp_offloads is managed by RCU. As it is actually included inside
the fou sockets, we cannot let the memory go out of scope before a grace
period. We either can synchronize_rcu or switch over to kfree_rcu to
manage the sockets. kfree_rcu seems appropriate as it is used by vxlan
and geneve.

Fixes: 23461551c00628c ("fou: Support for foo-over-udp RX path")
Cc: Tom Herbert 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: fix IP early demux races

2016-01-15T23:41:51+00:00

[ Upstream commit 5037e9ef9454917b047f9f3a19b4dd179fbf7cd4 ]

David Wilder reported crashes caused by dst reuse.


  I am seeing a crash on a distro V4.2.3 kernel caused by a double
  release of a dst_entry.  In ipv4_dst_destroy() the call to
  list_empty() finds a poisoned next pointer, indicating the dst_entry
  has already been removed from the list and freed. The crash occurs
  18 to 24 hours into a run of a network stress exerciser.


Thanks to his detailed report and analysis, we were able to understand
the core issue.

IP early demux can associate a dst to skb, after a lookup in TCP/UDP
sockets.

When socket cache is not properly set, we want to store into
sk->sk_dst_cache the dst for future IP early demux lookups,
by acquiring a stable refcount on the dst.

Problem is this acquisition is simply using an atomic_inc(),
which works well, unless the dst was queued for destruction from
dst_release() noticing dst refcount went to zero, if DST_NOCACHE
was set on dst.

We need to make sure current refcount is not zero before incrementing
it, or risk double free as David reported.

This patch, being a stable candidate, adds two new helpers, and use
them only from IP early demux problematic paths.

It might be possible to merge in net-next skb_dst_force() and
skb_dst_force_safe(), but I prefer having the smallest patch for stable
kernels : Maybe some skb_dst_force() callers do not expect skb->dst
can suddenly be cleared.

Can probably be backported back to linux-3.6 kernels

Reported-by: David J. Wilder 
Tested-by: David J. Wilder 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: add validation for the socket syscall protocol argument

2016-01-15T23:41:51+00:00

[ Upstream commit 79462ad02e861803b3840cc782248c7359451cd9 ]

郭永刚 reported that one could simply crash the kernel as root by
using a simple program:

	int socket_fd;
	struct sockaddr_in addr;
	addr.sin_port = 0;
	addr.sin_addr.s_addr = INADDR_ANY;
	addr.sin_family = 10;

	socket_fd = socket(10,3,0x40000000);
	connect(socket_fd , &addr,16);

AF_INET, AF_INET6 sockets actually only support 8-bit protocol
identifiers. inet_sock's skc_protocol field thus is sized accordingly,
thus larger protocol identifiers simply cut off the higher bits and
store a zero in the protocol fields.

This could lead to e.g. NULL function pointer because as a result of
the cut off inet_num is zero and we call down to inet_autobind, which
is NULL for raw sockets.

kernel: Call Trace:
kernel:  [] ? inet_autobind+0x2e/0x70
kernel:  [] inet_dgram_connect+0x54/0x80
kernel:  [] SYSC_connect+0xd9/0x110
kernel:  [] ? ptrace_notify+0x5b/0x80
kernel:  [] ? syscall_trace_enter_phase2+0x108/0x200
kernel:  [] SyS_connect+0xe/0x10
kernel:  [] tracesys_phase2+0x84/0x89

I found no particular commit which introduced this problem.

CVE: CVE-2015-8543
Cc: Cong Wang 
Reported-by: 郭永刚 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: ipmr: fix static mfc/dev leaks on table destruction

2015-12-14T17:19:25+00:00

[ Upstream commit 0e615e9601a15efeeb8942cf7cd4dadba0c8c5a7 ]

When destroying an mrt table the static mfc entries and the static
devices are kept, which leads to devices that can never be destroyed
(because of refcnt taken) and leaked memory, for example:
unreferenced object 0xffff880034c144c0 (size 192):
  comm "mfc-broken", pid 4777, jiffies 4320349055 (age 46001.964s)
  hex dump (first 32 bytes):
    98 53 f0 34 00 88 ff ff 98 53 f0 34 00 88 ff ff  .S.4.....S.4....
    ef 0a 0a 14 01 02 03 04 00 00 00 00 01 00 00 00  ................
  backtrace:
    [] kmemleak_alloc+0x4e/0xb0
    [] kmem_cache_alloc+0x190/0x300
    [] ip_mroute_setsockopt+0x5cb/0x910
    [] do_ip_setsockopt.isra.11+0x105/0xff0
    [] ip_setsockopt+0x30/0xa0
    [] raw_setsockopt+0x33/0x90
    [] sock_common_setsockopt+0x14/0x20
    [] SyS_setsockopt+0x71/0xc0
    [] entry_SYSCALL_64_fastpath+0x16/0x7a
    [] 0xffffffffffffffff

Make sure that everything is cleaned on netns destruction.

Signed-off-by: Nikolay Aleksandrov 
Reviewed-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

tcp: initialize tp->copied_seq in case of cross SYN connection

2015-12-14T17:19:25+00:00

[ Upstream commit 142a2e7ece8d8ac0e818eb2c91f99ca894730e2a ]

Dmitry provided a syzkaller (http://github.com/google/syzkaller)
generated program that triggers the WARNING at
net/ipv4/tcp.c:1729 in tcp_recvmsg() :

WARN_ON(tp->copied_seq != tp->rcv_nxt &&
        !(flags & (MSG_PEEK | MSG_TRUNC)));

His program is specifically attempting a Cross SYN TCP exchange,
that we support (for the pleasure of hackers ?), but it looks we
lack proper tcp->copied_seq initialization.

Thanks again Dmitry for your report and testings.

Signed-off-by: Eric Dumazet 
Reported-by: Dmitry Vyukov 
Tested-by: Dmitry Vyukov 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

tcp: fix potential huge kmalloc() calls in TCP_REPAIR

2015-12-14T17:19:24+00:00

[ Upstream commit 5d4c9bfbabdb1d497f21afd81501e5c54b0c85d9 ]

tcp_send_rcvq() is used for re-injecting data into tcp receive queue.

Problems :

- No check against size is performed, allowed user to fool kernel in
  attempting very large memory allocations, eventually triggering
  OOM when memory is fragmented.

- In case of fault during the copy we do not return correct errno.

Lets use alloc_skb_with_frags() to cook optimal skbs.

Fixes: 292e8d8c8538 ("tcp: Move rcvq sending to tcp_input.c")
Fixes: c0e88ff0f256 ("tcp: Repair socket queues")
Signed-off-by: Eric Dumazet 
Cc: Pavel Emelyanov 
Acked-by: Pavel Emelyanov 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

tcp: md5: fix lockdep annotation

2015-12-14T17:19:24+00:00

[ Upstream commit 1b8e6a01e19f001e9f93b39c32387961c91ed3cc ]

When a passive TCP is created, we eventually call tcp_md5_do_add()
with sk pointing to the child. It is not owner by the user yet (we
will add this socket into listener accept queue a bit later anyway)

But we do own the spinlock, so amend the lockdep annotation to avoid
following splat :

[ 8451.090932] net/ipv4/tcp_ipv4.c:923 suspicious rcu_dereference_protected() usage!
[ 8451.090932]
[ 8451.090932] other info that might help us debug this:
[ 8451.090932]
[ 8451.090934]
[ 8451.090934] rcu_scheduler_active = 1, debug_locks = 1
[ 8451.090936] 3 locks held by socket_sockopt_/214795:
[ 8451.090936]  #0:  (rcu_read_lock){.+.+..}, at: [] __netif_receive_skb_core+0x151/0xe90
[ 8451.090947]  #1:  (rcu_read_lock){.+.+..}, at: [] ip_local_deliver_finish+0x43/0x2b0
[ 8451.090952]  #2:  (slock-AF_INET){+.-...}, at: [] sk_clone_lock+0x1c5/0x500
[ 8451.090958]
[ 8451.090958] stack backtrace:
[ 8451.090960] CPU: 7 PID: 214795 Comm: socket_sockopt_

[ 8451.091215] Call Trace:
[ 8451.091216]    [] dump_stack+0x55/0x76
[ 8451.091229]  [] lockdep_rcu_suspicious+0xeb/0x110
[ 8451.091235]  [] tcp_md5_do_add+0x1bf/0x1e0
[ 8451.091239]  [] tcp_v4_syn_recv_sock+0x1f1/0x4c0
[ 8451.091242]  [] ? tcp_v4_md5_hash_skb+0x167/0x190
[ 8451.091246]  [] tcp_check_req+0x3c8/0x500
[ 8451.091249]  [] ? tcp_v4_inbound_md5_hash+0x11e/0x190
[ 8451.091253]  [] tcp_v4_rcv+0x3c0/0x9f0
[ 8451.091256]  [] ? ip_local_deliver_finish+0x43/0x2b0
[ 8451.091260]  [] ip_local_deliver_finish+0xb6/0x2b0
[ 8451.091263]  [] ? ip_local_deliver_finish+0x43/0x2b0
[ 8451.091267]  [] ip_local_deliver+0x48/0x80
[ 8451.091270]  [] ip_rcv_finish+0x160/0x700
[ 8451.091273]  [] ip_rcv+0x29e/0x3d0
[ 8451.091277]  [] __netif_receive_skb_core+0xb47/0xe90

Fixes: a8afca0329988 ("tcp: md5: protects md5sig_info with RCU")
Signed-off-by: Eric Dumazet 
Reported-by: Willem de Bruijn 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ipv4: disable BH when changing ip local port range

2015-12-14T17:17:30+00:00

[ Upstream commit 4ee3bd4a8c7463cdef0b82ebc33fc94a9170a7e0 ]

This fixes the following lockdep warning:

 [ INFO: inconsistent lock state ]
 4.3.0-rc7+ #1197 Not tainted
 ---------------------------------
 inconsistent {IN-SOFTIRQ-R} -> {SOFTIRQ-ON-W} usage.
 sysctl/1019 [HC0[0]:SC0[0]:HE1:SE1] takes:
  (&(&net->ipv4.ip_local_ports.lock)->seqcount){+.+-..}, at: [] ipv4_local_port_range+0xb4/0x12a
 {IN-SOFTIRQ-R} state was registered at:
   [] __lock_acquire+0x2f6/0xdf0
   [] lock_acquire+0x11c/0x1a4
   [] inet_get_local_port_range+0x4e/0xae
   [] udp_flow_src_port.constprop.40+0x23/0x116
   [] vxlan_xmit_one+0x219/0xa6a
   [] vxlan_xmit+0xa6b/0xaa5
   [] dev_hard_start_xmit+0x2ae/0x465
   [] __dev_queue_xmit+0x531/0x633
   [] dev_queue_xmit_sk+0x13/0x15
   [] neigh_resolve_output+0x12f/0x14d
   [] ip6_finish_output2+0x344/0x39f
   [] ip6_finish_output+0x88/0x8e
   [] ip6_output+0x91/0xe5
   [] dst_output_sk+0x47/0x4c
   [] NF_HOOK_THRESH.constprop.30+0x38/0x82
   [] mld_sendpack+0x189/0x266
   [] mld_ifc_timer_expire+0x1ef/0x223
   [] call_timer_fn+0xfb/0x28c
   [] run_timer_softirq+0x1c7/0x1f1

Fixes: b8f1a55639e6 ("udp: Add function to make source port for UDP tunnels")
Cc: Tom Herbert 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ipv6: gre: support SIT encapsulation

2015-12-03T15:18:20+00:00

[ Upstream commit 7e3b6e7423d5f994257c1de88e06b509673fdbcf ]

gre_gso_segment() chokes if SIT frames were aggregated by GRO engine.

Fixes: 61c1db7fae21e ("ipv6: sit: add GSO/TSO support")
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ipmr: fix possible race resulting from improper usage of IP_INC_STATS_BH() in preemptible context.

2015-12-03T15:12:17+00:00

[ Upstream commit 44f49dd8b5a606870a1f21101522a0f9c4414784 ]

Fixes the following kernel BUG :

BUG: using __this_cpu_add() in preemptible [00000000] code: bash/2758
caller is __this_cpu_preempt_check+0x13/0x15
CPU: 0 PID: 2758 Comm: bash Tainted: P           O   3.18.19 #2
 ffffffff8170eaca ffff880110d1b788 ffffffff81482b2a 0000000000000000
 0000000000000000 ffff880110d1b7b8 ffffffff812010ae ffff880007cab800
 ffff88001a060800 ffff88013a899108 ffff880108b84240 ffff880110d1b7c8
Call Trace:
[] dump_stack+0x52/0x80
[] check_preemption_disabled+0xce/0xe1
[] __this_cpu_preempt_check+0x13/0x15
[] ipmr_queue_xmit+0x647/0x70c
[] ip_mr_forward+0x32f/0x34e
[] ip_mroute_setsockopt+0xe03/0x108c
[] ? get_parent_ip+0x11/0x42
[] ? pollwake+0x4d/0x51
[] ? default_wake_function+0x0/0xf
[] ? get_parent_ip+0x11/0x42
[] ? __wake_up_common+0x45/0x77
[] ? _raw_spin_unlock_irqrestore+0x1d/0x32
[] ? __wake_up_sync_key+0x4a/0x53
[] ? sock_def_readable+0x71/0x75
[] do_ip_setsockopt+0x9d/0xb55
[] ? unix_seqpacket_sendmsg+0x3f/0x41
[] ? sock_sendmsg+0x6d/0x86
[] ? sockfd_lookup_light+0x12/0x5d
[] ? SyS_sendto+0xf3/0x11b
[] ? new_sync_read+0x82/0xaa
[] compat_ip_setsockopt+0x3b/0x99
[] compat_raw_setsockopt+0x11/0x32
[] compat_sock_common_setsockopt+0x18/0x1f
[] compat_SyS_setsockopt+0x1a9/0x1cf
[] compat_SyS_socketcall+0x180/0x1e3
[] cstar_dispatch+0x7/0x1e

Signed-off-by: Ani Sinha 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin