Special care is taken inside sk_port_alloc to avoid overwriting
skc_node/skc_nulls_node. We should also avoid overwriting
skc_bind_node/skc_portaddr_node.

The patch fixes the following crash:

 BUG: unable to handle kernel paging request at fffffffffffffff0
 IP: [<ffffffff812ec6dd>] udp4_lib_lookup2+0xad/0x370
 [<ffffffff812ecc22>] __udp4_lib_lookup+0x282/0x360
 [<ffffffff812ed63e>] __udp4_lib_rcv+0x31e/0x700
 [<ffffffff812bba45>] ? ip_local_deliver_finish+0x65/0x190
 [<ffffffff812bbbf8>] ? ip_local_deliver+0x88/0xa0
 [<ffffffff812eda35>] udp_rcv+0x15/0x20
 [<ffffffff812bba45>] ip_local_deliver_finish+0x65/0x190
 [<ffffffff812bbbf8>] ip_local_deliver+0x88/0xa0
 [<ffffffff812bb2cd>] ip_rcv_finish+0x32d/0x6f0
 [<ffffffff8128c14c>] ? netif_receive_skb+0x99c/0x11c0
 [<ffffffff812bb94b>] ip_rcv+0x2bb/0x350
 [<ffffffff8128c14c>] netif_receive_skb+0x99c/0x11c0
Signed-off-by: NLeonard Crestez <lcrestez@ixiacom.com>
Signed-off-by: NOctavian Purdila <opurdila@ixiacom.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The first big packets sent to a "low-MTU" client correctly
triggers the creation of a temporary route containing the reduced MTU.

But after the temporary route has expired, new ICMP6 "packet too big"
will be sent, rt6_pmtu_discovery will find the previous EXPIRED route
check that its mtu isn't bigger then in icmp packet and do nothing
before the temporary route will not deleted by gc.

I make the simple experiment:
while :; do
    time ( dd if=/dev/zero bs=10K count=1 | ssh hostname dd of=/dev/null ) || break;
done

The "time" reports real 0m0.197s if a temporary route isn't expired, but
it reports real 0m52.837s (!!!!) immediately after a temporare route has
expired.
Signed-off-by: NAndrey Vagin <avagin@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On suspend, there might be usb wireless drivers which wrongly trigger
the warning in ieee80211_work_work. If an usb driver doesn't have a
suspend hook, the usb stack will disconnect the device. On disconnect,
a mac80211 driver calls ieee80211_unregister_hw, which calls dev_close,
which calls ieee80211_stop, and in the end calls ieee80211_work_purge->
ieee80211_work_work.

The problem is that this call to ieee80211_work_purge comes after
mac80211 is suspended, triggering the warning even when we don't have
work queued in work_list (the expected case when already suspended),
because it always calls ieee80211_work_work.

So, just call ieee80211_work_work in ieee80211_work_purge if we really
have to abort work. This addresses the warning reported at
https://bugzilla.kernel.org/show_bug.cgi?id=24402Signed-off-by: NHerton Ronaldo Krzesinski <herton@mandriva.com.br>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

dev_open will eventually call ieee80211_ibss_join which sets up the
skb used for beacons/probe-responses however it is possible to
receive beacons that attempt to merge before this occurs causing
a null pointer dereference.  Check ssid_len as that is the last
thing set in ieee80211_ibss_join.

This occurs quite easily in the presence of adhoc nodes with hidden SSID's

revised previous patch to check further up based on irc feedback
Signed-off-by: NTim Harvey <harvey.tim@gmail.com>
Reviewed-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

After commit c1f19b51 (net: support time stamping in phy devices.),
kernel might crash if CONFIG_NETWORK_PHY_TIMESTAMPING=y and
skb_defer_rx_timestamp() handles a packet without an ethernet header.

Fixes kernel bugzilla #24102

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=24102Reported-and-tested-by: NAndrew Watts <akwatts@ymail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ATM subsystem was incorrectly creating the 'device' link for ATM
nodes in sysfs.  This led to incorrect device/parent relationships
exposed by sysfs and udev.  Instead of rolling the 'device' link by hand
in the generic ATM code, pass each ATM driver's bus device down to the
sysfs code and let sysfs do this stuff correctly.
Signed-off-by: NDan Williams <dcbw@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SCTP_SET_PEER_PRIMARY_ADDR does not accpet v4mapped address, using
v4mapped address in SCTP_SET_PEER_PRIMARY_ADDR socket option will
get -EADDRNOTAVAIL error if v4map is enabled. This patch try to
fix it by mapping v4mapped address to v4 address if allowed.
Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Acked-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

New idev are advertised with NL group RTNLGRP_IPV6_IFADDR, but
should use RTNLGRP_IPV6_IFINFO.
Bug was introduced by commit 8d7a76c9.
Signed-off-by: NWang Xuefu <xuefu.wang@6wind.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: NThomas Graf <tgraf@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NMartin Lucina <mato@kotelna.sk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

xfrm_state_migrate calls kfree instead of xfrm_state_put to free
a failed state. According to git commit 553f9118 this can cause
memory leaks.
Signed-off-by: NThomas Egerer <thomas.egerer@secunet.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Unconditional use of skb->dev won't work here,
try to fetch the econet device via skb_dst()->dev
instead.

Suggested by Eric Dumazet.
Reported-by: NNelson Elhage <nelhage@ksplice.com>
Tested-by: NNelson Elhage <nelhage@ksplice.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make sure sysctl_tcp_cookie_size is read once in
tcp_cookie_size_check(), or we might return an illegal value to caller
if sysctl_tcp_cookie_size is changed by another cpu.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: William Allen Simpson <william.allen.simpson@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sysctl_tcp_tso_win_divisor might be set to zero while one cpu runs in
tcp_tso_should_defer(). Make sure we dont allow a divide by zero by
reading sysctl_tcp_tso_win_divisor exactly once.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

mac80211 doesn't handle shared skbs correctly at the moment. As a result
a possible resize can trigger a BUG in pskb_expand_head.

[  676.030000] Kernel bug detected[#1]:
[  676.030000] Cpu 0
[  676.030000] $ 0   : 00000000 00000000 819662ff 00000002
[  676.030000] $ 4   : 81966200 00000020 00000000 00000020
[  676.030000] $ 8   : 819662e0 800043c0 00000002 00020000
[  676.030000] $12   : 3b9aca00 00000000 00000000 00470000
[  676.030000] $16   : 80ea2000 00000000 00000000 00000000
[  676.030000] $20   : 818aa200 80ea2018 80ea2000 00000008
[  676.030000] $24   : 00000002 800ace5c
[  676.030000] $28   : 8199a000 8199bd20 81938f88 80f180d4
[  676.030000] Hi    : 0000026e
[  676.030000] Lo    : 0000757e
[  676.030000] epc   : 801245e4 pskb_expand_head+0x44/0x1d8
[  676.030000]     Not tainted
[  676.030000] ra    : 80f180d4 ieee80211_skb_resize+0xb0/0x114 [mac80211]
[  676.030000] Status: 1000a403    KERNEL EXL IE
[  676.030000] Cause : 10800024
[  676.030000] PrId  : 0001964c (MIPS 24Kc)
[  676.030000] Modules linked in: mac80211_hwsim rt2800lib rt2x00soc rt2x00pci rt2x00lib mac80211 crc_itu_t crc_ccitt cfg80211 compat arc4 aes_generic deflate ecb cbc [last unloaded: rt2800pci]
[  676.030000] Process kpktgend_0 (pid: 97, threadinfo=8199a000, task=81879f48, tls=00000000)
[  676.030000] Stack : ffffffff 00000000 00000000 00000014 00000004 80ea2000 00000000 00000000
[  676.030000]         818aa200 80f180d4 ffffffff 0000000a 81879f78 81879f48 81879f48 00000018
[  676.030000]         81966246 80ea2000 818432e0 80f1a420 80203050 81814d98 00000001 81879f48
[  676.030000]         81879f48 00000018 81966246 818432e0 0000001a 8199bdd4 0000001c 80f1b72c
[  676.030000]         80203020 8001292c 80ef4aa2 7f10b55d 801ab5b8 81879f48 00000188 80005c90
[  676.030000]         ...
[  676.030000] Call Trace:
[  676.030000] [<801245e4>] pskb_expand_head+0x44/0x1d8
[  676.030000] [<80f180d4>] ieee80211_skb_resize+0xb0/0x114 [mac80211]
[  676.030000] [<80f1a420>] ieee80211_xmit+0x150/0x22c [mac80211]
[  676.030000] [<80f1b72c>] ieee80211_subif_start_xmit+0x6f4/0x73c [mac80211]
[  676.030000] [<8014361c>] pktgen_thread_worker+0xfac/0x16f8
[  676.030000] [<8002ebe8>] kthread+0x7c/0x88
[  676.030000] [<80008e0c>] kernel_thread_helper+0x10/0x18
[  676.030000]
[  676.030000]
[  676.030000] Code: 24020001  10620005  2502001f <0200000d> 0804917a  00000000  2502001f  00441023  00531021

Fix this by making a local copy of shared skbs prior to mangeling them.
To avoid copying the skb unnecessarily move the skb_copy call below the
checks that don't need write access to the skb.

Also, move the assignment of nh_pos and h_pos below the skb_copy to point
to the correct skb.

It would be possible to avoid another resize of the copied skb by using
skb_copy_expand instead of skb_copy but that would make the patch more
complex. Also, shared skbs are a corner case right now, so the resize
shouldn't matter much.

Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Rather than printing the message to the log, use a mib counter to keep
track of the count of occurences of time wait bucket overflow.  Reduces
spam in logs.
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

x25 does not decrement the network device reference counts on module unload.
Thus unregistering any pre-existing interface after unloading the x25 module
hangs and results in

 unregister_netdevice: waiting for tap0 to become free. Usage count = 1

This patch decrements the reference counts of all interfaces in x25_link_free,
the way it is already done in x25_link_device_down for NETDEV_DOWN events.
Signed-off-by: NApollon Oikonomopoulos <apollon@noc.grnet.gr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Using the SOCK_DGRAM enum results in
"net-pf-2-proto-SOCK_DGRAM-type-115", so use the numeric value like it
is done in net/dccp.
Signed-off-by: NMichal Marek <mmarek@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We need to drop the mutex and do a dev_put, so set an error code and break like
the other paths, instead of returning directly.
Signed-off-by: NNelson Elhage <nelhage@ksplice.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Le dimanche 05 décembre 2010 à 12:23 +0100, Eric Dumazet a écrit :
> Le dimanche 05 décembre 2010 à 09:19 +0100, Eric Dumazet a écrit :
>
> > Hmm..
> >
> > If somebody can explain why RTNL is held in arp_ioctl() (and therefore
> > in arp_req_delete()), we might first remove RTNL use in arp_ioctl() so
> > that your patch can be applied.
> >
> > Right now it is not good, because RTNL wont be necessarly held when you
> > are going to call arp_invalidate() ?
>
> While doing this analysis, I found a refcount bug in llc, I'll send a
> patch for net-2.6

Oh well, of course I must first fix the bug in net-2.6, and wait David
pull the fix in net-next-2.6 before sending this rcu conversion.

Note: this patch should be sent to stable teams (2.6.34 and up)

[PATCH net-2.6] llc: fix a device refcount imbalance

commit abf9d537 (llc: add support for SO_BINDTODEVICE) added one
refcount imbalance in llc_ui_bind(), because dev_getbyhwaddr() doesnt
take a reference on device, while dev_get_by_index() does.

Fix this using RCU locking. And since an RCU conversion will be done for
2.6.38 for dev_getbyhwaddr(), put the rcu_read_lock/unlock exactly at
their final place.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: stable@kernel.org
Cc: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The bug has to do with boundary checks on the initial receive window.
If the initial receive window falls between init_cwnd and the
receive window specified by the user, the initial window is incorrectly
brought down to init_cwnd. The correct behavior is to allow it to
remain unchanged.
Signed-off-by: NNandita Dukkipati <nanditad@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Due to commit 63ce0900 connections initiated through TTYs created with
"rfcomm bind ..." would have security level BT_SECURITY_SDP instead of
BT_SECURITY_LOW. This would cause instant connection failure between any
two SSP capable devices due to the L2CAP connect request to RFCOMM being
sent before authentication has been performed. This patch fixes the
regression by always initializing the DLC security level to
BT_SECURITY_LOW.
Signed-off-by: NJohan Hedberg <johan.hedberg@nokia.com>
Acked-by: NLuiz Augusto von Dentz <luiz.dentz-von@nokia.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Pavel Emelyanov tried to fix a race between sk_filter_(de|at)tach and
sk_clone() in commit 47e958ea

Problem is we can have several clones sharing a common sk_filter, and
these clones might want to sk_filter_attach() their own filters at the
same time, and can overwrite old_filter->rcu, corrupting RCU queues.

We can not use filter->rcu without being sure no other thread could do
the same thing.

Switch code to a more conventional ref-counting technique : Do the
atomic decrement immediately and queue one rcu call back when last
reference is released.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I found a problem using an IPv6 over IPv4 tunnel.  When CONFIG_IPV6_SIT
was enabled, the packets would be rejected as net/ipv6/sit.c was catching
all IPPROTO_IPV6 packets and returning an ICMP port unreachable error.

I think this patch fixes the problem cleanly.  I believe the code in
net/ipv4/tunnel4.c:tunnel4_rcv takes care of it properly if none of the
handlers claim the skb.
Signed-off-by: NDavid McCullough <david_mccullough@mcafee.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ip6_tunnel always assumes it consumes 40 bytes (ip6 hdr) of the mtu of the
underlaying device. So for a normal ethernet bearer, the mtu of the ip6_tunnel is
1460.
However, when creating a tunnel the encap limit option is enabled by default, and it
consumes 8 bytes more, so the true mtu shall be 1452.

I dont really know if this breaks some statement in some RFC, so this is a request for
comments.
Signed-off-by: NAnders Franzen <anders.franzen@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Th commit titled "mac80211: clean up rx handling wrt. found_sta"
removed found_sta variable which caused a MIC failure event
to be reported twice for a single failure to supplicant resulted
in STA disconnect.

This should fix WPA specific countermeasures WiFi test case (5.2.17)
issues with mac80211 based drivers which report MIC failure events in
rx status.

Cc: Stable <stable@kernel.org> (2.6.37)
Signed-off-by: NSenthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch fixes an curious issue due to insufficient
rx frame filtering.

Saqeb Akhter reported frequent disconnects while streaming
videos over samba: <http://marc.info/?m=128600031109136>
> [ 1166.512087] wlan1: deauthenticated from 30:46:9a:10:49:f7 (Reason: 7)
> [ 1526.059997] wlan1: deauthenticated from 30:46:9a:10:49:f7 (Reason: 7)
> [ 2125.324356] wlan1: deauthenticated from 30:46:9a:10:49:f7 (Reason: 7)
> [...]

The reason is that the device generates frames with slightly
bogus SA/TA addresses.

e.g.:
 [ 2314.402316] Ignore 9f:1f:31:f8:64:ff
 [ 2314.402321] Ignore 9f:1f:31:f8:64:ff
 [ 2352.453804] Ignore 0d:1f:31:f8:64:ff
 [ 2352.453808] Ignore 0d:1f:31:f8:64:ff
 					   ^^ the group-address flag is set!
 (the correct SA/TA would be: 00:1f:31:f8:64:ff)

Since the AP does not know from where the frames come, it
generates a DEAUTH response for the (invalid) mcast address.
This mcast deauth frame then passes through all filters and
tricks the stack into thinking that the AP brutally kicked
us!

This patch fixes the problem by simply ignoring
non-broadcast, group-addressed deauth/disassoc frames.

Cc: Jouni Malinen <j@w1.fi>
Cc: Johannes Berg <johannes@sipsolutions.net>
Reported-by: NSaqeb Akhter <saqeb.akhter@gmail.com>
Signed-off-by: NChristian Lamparter <chunkeey@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In order for frame injection to work properly for some use cases
(e.g., finding the station entry and keys for encryption), mac80211
needs to find the correct sdata entry. This works when the main vif
is in AP mode, but commit a2c1e3da
broke this particular use case for station main vif. While this type of
injection is quite unusual operation, it has some uses and we should fix
it. Do this by changing the monitor vif sdata selection to allow station
vif to be selected instead of limiting it to just AP vifs. We still need
to skip some iftypes to avoid selecting unsuitable vif for injection.
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Its easy to eat all kernel memory and trigger NMI watchdog, using an
exploit program that queues unix sockets on top of others.

lkml ref : http://lkml.org/lkml/2010/11/25/8

This mechanism is used in applications, one choice we have is to have a
recursion limit.

Other limits might be needed as well (if we queue other types of files),
since the passfd mechanism is currently limited by socket receive queue
sizes only.

Add a recursion_level to unix socket, allowing up to 4 levels.

Each time we send an unix socket through sendfd mechanism, we copy its
recursion level (plus one) to receiver. This recursion level is cleared
when socket receive queue is emptied.
Reported-by: NМарк Коренберг <socketpair@gmail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

inet sockets corresponding to passive connections are added to the bind hash
using ___inet_inherit_port(). These sockets are later removed from the bind
hash using __inet_put_port(). These two functions are not exactly symmetrical.
__inet_put_port() decrements hashinfo->bsockets and tb->num_owners, whereas
___inet_inherit_port() does not increment them. This results in both of these
going to -ve values.

This patch fixes this by calling inet_bind_hash() from ___inet_inherit_port(),
which does the right thing.

'bsockets' and 'num_owners' were introduced by commit a9d8f911
(inet: Allowing more than 64k connections and heavily optimize bind(0))
Signed-off-by: NNagendra Singh Tomar <tomer_iisc@yahoo.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Acked-by: NEvgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A single uninitialized padding byte is leaked to userspace.
Signed-off-by: NDan Rosenberg <drosenberg@vsecurity.com>
CC: stable <stable@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This fixes a bug in updating the Greatest Acknowledgment number Received (GAR):
the current implementation does not track the greatest received value -
lower values in the range AWL..AWH (RFC 4340, 7.5.1) erase higher ones.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcp_win_from_space() does the following:

      if (sysctl_tcp_adv_win_scale <= 0)
              return space >> (-sysctl_tcp_adv_win_scale);
      else
              return space - (space >> sysctl_tcp_adv_win_scale);

"space" is int.

As per C99 6.5.7 (3) shifting int for 32 or more bits is
undefined behaviour.

Indeed, if sysctl_tcp_adv_win_scale is exactly 32,
space >> 32 equals space and function returns 0.

Which means we busyloop in tcp_fixup_rcvbuf().

Restrict net.ipv4.tcp_adv_win_scale to [-31, 31].

Fix https://bugzilla.kernel.org/show_bug.cgi?id=20312

Steps to reproduce:

      echo 32 >/proc/sys/net/ipv4/tcp_adv_win_scale
      wget www.kernel.org
      [softlockup]
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The /proc/net/tcp leaks openreq sockets from other namespaces.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove the if and else conditional because the code is in mainline and there
is no need in it being there.
Signed-off-by: NTracey Dent <tdent48227@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't declare variable sized array of iovecs on the stack since this
could cause stack overflow if msg->msgiovlen is large.  Instead, coalesce
the user-supplied data into a new buffer and use a single iovec for it.
Signed-off-by: NPhil Blundell <philb@gnu.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add missing check for capable(CAP_NET_ADMIN) in SIOCSIFADDR operation.
Signed-off-by: NPhil Blundell <philb@gnu.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Later parts of econet_sendmsg() rely on saddr != NULL, so return early
with EINVAL if NULL was passed otherwise an oops may occur.
Signed-off-by: NPhil Blundell <philb@gnu.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use TCP_MIN_MSS instead of constant 64.
Reported-by: NMin Zhang <mzhang@mvista.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Vegard Nossum found a unix socket OOM was possible, posting an exploit
program.

My analysis is we can eat all LOWMEM memory before unix_gc() being
called from unix_release_sock(). Moreover, the thread blocked in
unix_gc() can consume huge amount of time to perform cleanup because of
huge working set.

One way to handle this is to have a sensible limit on unix_tot_inflight,
tested from wait_for_unix_gc() and to force a call to unix_gc() if this
limit is hit.

This solves the OOM and also reduce overall latencies, and should not
slowdown normal workloads.
Reported-by: NVegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Return 0 in that situation could lead to errors in the caller.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>