Linux 3.0.64 (Squashed commit)

rtlwifi: Fix the usage of the wrong variable in usb.c

commit 0a06ad8e3a1cb5311b7dbafde45410aa1bce9d40 upstream.

In routine _rtl_rx_pre_process(), skb_dequeue() is called to get an skb;
however, the wrong variable name is used in subsequent calls.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

virtio_console: Don't access uninitialized data.

commit aded024a12b32fc1ed9a80639681daae2d07ec25 upstream.

Don't access uninitialized work-queue when removing device.
The work queue is initialized only if the device multi-queue.
So don't call cancel_work unless this is a multi-queue device.

This fixes the following panic:

Kernel panic - not syncing: BUG!
Call Trace:
62031b28:  [<6026085d>] panic+0x16b/0x2d3
62031b30:  [<6004ef5e>] flush_work+0x0/0x1d7
62031b60:  [<602606f2>] panic+0x0/0x2d3
62031b68:  [<600333b0>] memcpy+0x0/0x140
62031b80:  [<6002d58a>] unblock_signals+0x0/0x84
62031ba0:  [<602609c5>] printk+0x0/0xa0
62031bd8:  [<60264e51>] __mutex_unlock_slowpath+0x13d/0x148
62031c10:  [<6004ef5e>] flush_work+0x0/0x1d7
62031c18:  [<60050234>] try_to_grab_pending+0x0/0x17e
62031c38:  [<6004e984>] get_work_gcwq+0x71/0x8f
62031c48:  [<60050539>] __cancel_work_timer+0x5b/0x115
62031c78:  [<628acc85>] unplug_port+0x0/0x191 [virtio_console]
62031c98:  [<6005061c>] cancel_work_sync+0x12/0x14
62031ca8:  [<628ace96>] virtcons_remove+0x80/0x15c [virtio_console]
62031ce8:  [<628191de>] virtio_dev_remove+0x1e/0x7e [virtio]
62031d08:  [<601cf242>] __device_release_driver+0x75/0xe4
62031d28:  [<601cf2dd>] device_release_driver+0x2c/0x40
62031d48:  [<601ce0dd>] driver_unbind+0x7d/0xc6
62031d88:  [<601cd5d9>] drv_attr_store+0x27/0x29
62031d98:  [<60115f61>] sysfs_write_file+0x100/0x14d
62031df8:  [<600b737d>] vfs_write+0xcb/0x184
62031e08:  [<600b58b8>] filp_close+0x88/0x94
62031e38:  [<600b7686>] sys_write+0x59/0x88
62031e88:  [<6001ced1>] handle_syscall+0x5d/0x80
62031ea8:  [<60030a74>] userspace+0x405/0x531
62031f08:  [<600d32cc>] sys_dup+0x0/0x5e
62031f28:  [<601b11d6>] strcpy+0x0/0x18
62031f38:  [<600be46c>] do_execve+0x10/0x12
62031f48:  [<600184c7>] run_init_process+0x43/0x45
62031fd8:  [<60019a91>] new_thread_handler+0xba/0xbc

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel/resource.c: fix stack overflow in __reserve_region_with_split()

commit 4965f5667f36a95b41cda6638875bc992bd7d18b upstream.

Using a recursive call add a non-conflicting region in
__reserve_region_with_split() could result in a stack overflow in the case
that the recursive calls are too deep.  Convert the recursive calls to an
iterative loop to avoid the problem.

Tested on a machine containing 135 regions.  The kernel no longer panicked
with stack overflow.

Also tested with code arbitrarily adding regions with no conflict,
embedding two consecutive conflicts and embedding two non-consecutive
conflicts.

Signed-off-by: T Makphaibulchoke <tmac@hp.com>
Reviewed-by: Ram Pai <linuxram@us.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@gmail.com>
Cc: Wei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mac80211: synchronize scan off/on-channel and PS states

commit aacde9ee45225f7e0b90960f479aef83c66bfdc0 upstream.

Since:

commit b23b025fe246f3acc2988eb6d400df34c27cb8ae
Author: Ben Greear <greearb@candelatech.com>
Date:   Fri Feb 4 11:54:17 2011 -0800

    mac80211: Optimize scans on current operating channel.

we do not disable PS while going back to operational channel (on
ieee80211_scan_state_suspend) and deffer that until scan finish.
But since we are allowed to send frames, we can send a frame to AP
without PM bit set, so disable PS on AP side. Then when we switch
to off-channel (in ieee80211_scan_state_resume) we do not enable PS.
Hence we are off-channel with PS disabled, frames are not buffered
by AP.

To fix remove offchannel_ps_disable argument and always enable PS when
going off-channel and disable it when going on-channel, like it was
before.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Tested-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net: prevent setting ttl=0 via IP_TTL

[ Upstream commit c9be4a5c49cf51cc70a993f004c5bb30067a65ce ]

A regression is introduced by the following commit:

	commit 4d52cfbef6266092d535237ba5a4b981458ab171
	Author: Eric Dumazet <eric.dumazet@gmail.com>
	Date:   Tue Jun 2 00:42:16 2009 -0700

	    net: ipv4/ip_sockglue.c cleanups

	    Pure cleanups

but it is not a pure cleanup...

	-               if (val != -1 && (val < 1 || val>255))
	+               if (val != -1 && (val < 0 || val > 255))

Since there is no reason provided to allow ttl=0, change it back.

Reported-by: nitin padalia <padalia.nitin@gmail.com>
Cc: nitin padalia <padalia.nitin@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MAINTAINERS: Stephen Hemminger email change

[ Upstream commit adbbf69d1a54abf424e91875746a610dcc80017d ]

I changed my email because the vyatta.com mail server is now
redirected to brocade.com; and the Brocade mail system
is not friendly to Linux desktop users.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

isdn/gigaset: fix zero size border case in debug dump

[ Upstream commit d721a1752ba544df8d7d36959038b26bc92bdf80 ]

If subtracting 12 from l leaves zero we'd do a zero size allocation,
leading to an oops later when we try to set the NUL terminator.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

r8169: remove the obsolete and incorrect AMD workaround

[ Upstream commit 5d0feaff230c0abfe4a112e6f09f096ed99e0b2d ]

This was introduced in commit 6dccd16 "r8169: merge with version
6.001.00 of Realtek's r8169 driver". I did not find the version
6.001.00 online, but in 6.002.00 or any later r8169 from Realtek
this hunk is no longer present.

Also commit 05af214 "r8169: fix Ethernet Hangup for RTL8110SC
rev d" claims to have fixed this issue otherwise.

The magic compare mask of 0xfffe000 is dubious as it masks
parts of the Reserved part, and parts of the VLAN tag. But this
does not make much sense as the VLAN tag parts are perfectly
valid there. In matter of fact this seems to be triggered with
any VLAN tagged packet as RxVlanTag bit is matched. I would
suspect 0xfffe0000 was intended to test reserved part only.

Finally, this hunk is evil as it can cause more packets to be
handled than what was NAPI quota causing net/core/dev.c:
net_rx_action(): WARN_ON_ONCE(work > weight) to trigger, and
mess up the NAPI state causing device to hang.

As result, any system using VLANs and having high receive
traffic (so that NAPI poll budget limits rtl_rx) would result
in device hang.

Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Acked-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net: loopback: fix a dst refcounting issue

[ Upstream commit 794ed393b707f01858f5ebe2ae5eabaf89d00022 ]

Ben Greear reported crashes in ip_rcv_finish() on a stress
test involving many macvlans.

We tracked the bug to a dst use after free. ip_rcv_finish()
was calling dst->input() and got garbage for dst->input value.

It appears the bug is in loopback driver, lacking
a skb_dst_force() before calling netif_rx().

As a result, a non refcounted dst, normally protected by a
RCU read_lock section, was escaping this section and could
be freed before the packet being processed.

  [<ffffffff813a3c4d>] loopback_xmit+0x64/0x83
  [<ffffffff81477364>] dev_hard_start_xmit+0x26c/0x35e
  [<ffffffff8147771a>] dev_queue_xmit+0x2c4/0x37c
  [<ffffffff81477456>] ? dev_hard_start_xmit+0x35e/0x35e
  [<ffffffff8148cfa6>] ? eth_header+0x28/0xb6
  [<ffffffff81480f09>] neigh_resolve_output+0x176/0x1a7
  [<ffffffff814ad835>] ip_finish_output2+0x297/0x30d
  [<ffffffff814ad6d5>] ? ip_finish_output2+0x137/0x30d
  [<ffffffff814ad90e>] ip_finish_output+0x63/0x68
  [<ffffffff814ae412>] ip_output+0x61/0x67
  [<ffffffff814ab904>] dst_output+0x17/0x1b
  [<ffffffff814adb6d>] ip_local_out+0x1e/0x23
  [<ffffffff814ae1c4>] ip_queue_xmit+0x315/0x353
  [<ffffffff814adeaf>] ? ip_send_unicast_reply+0x2cc/0x2cc
  [<ffffffff814c018f>] tcp_transmit_skb+0x7ca/0x80b
  [<ffffffff814c3571>] tcp_connect+0x53c/0x587
  [<ffffffff810c2f0c>] ? getnstimeofday+0x44/0x7d
  [<ffffffff810c2f56>] ? ktime_get_real+0x11/0x3e
  [<ffffffff814c6f9b>] tcp_v4_connect+0x3c2/0x431
  [<ffffffff814d6913>] __inet_stream_connect+0x84/0x287
  [<ffffffff814d6b38>] ? inet_stream_connect+0x22/0x49
  [<ffffffff8108d695>] ? _local_bh_enable_ip+0x84/0x9f
  [<ffffffff8108d6c8>] ? local_bh_enable+0xd/0x11
  [<ffffffff8146763c>] ? lock_sock_nested+0x6e/0x79
  [<ffffffff814d6b38>] ? inet_stream_connect+0x22/0x49
  [<ffffffff814d6b49>] inet_stream_connect+0x33/0x49
  [<ffffffff814632c6>] sys_connect+0x75/0x98

This bug was introduced in linux-2.6.35, in commit
7fee226ad2397b (net: add a noref bit on skb dst)

skb_dst_force() is enforced in dev_queue_xmit() for devices having a
qdisc.

Reported-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

pktgen: correctly handle failures when adding a device

[ Upstream commit 604dfd6efc9b79bce432f2394791708d8e8f6efc ]

The return value of pktgen_add_device() is not checked, so
even if we fail to add some device, for example, non-exist one,
we still see "OK:...". This patch fixes it.

After this patch, I got:

	# echo "add_device non-exist" > /proc/net/pktgen/kpktgend_0
	-bash: echo: write error: No such device
	# cat /proc/net/pktgen/kpktgend_0
	Running:
	Stopped:
	Result: ERROR: can not add device non-exist
	# echo "add_device eth0" > /proc/net/pktgen/kpktgend_0
	# cat /proc/net/pktgen/kpktgend_0
	Running:
	Stopped: eth0
	Result: OK: add_device=eth0

(Candidate for -stable)

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ipv6: do not create neighbor entries for local delivery

[ Upstream commit bd30e947207e2ea0ff2c08f5b4a03025ddce48d3 ]

They will be created at output, if ever needed. This avoids creating
empty neighbor entries when TPROXYing/Forwarding packets for addresses
that are not even directly reachable.

Note that IPv4 already handles it this way. No neighbor entries are
created for local input.

Tested by myself and customer.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

packet: fix leakage of tx_ring memory

[ Upstream commit 9665d5d62487e8e7b1f546c00e11107155384b9a ]

When releasing a packet socket, the routine packet_set_ring() is reused
to free rings instead of allocating them. But when calling it for the
first time, it fills req->tp_block_nr with the value of rb->pg_vec_len
which in the second invocation makes it bail out since req->tp_block_nr
is greater zero but req->tp_block_size is zero.

This patch solves the problem by passing a zeroed auto-variable to
packet_set_ring() upon each invocation from packet_release().

As far as I can tell, this issue exists even since 69e3c75 (net: TX_RING
and packet mmap), i.e. the original inclusion of TX ring support into
af_packet, but applies only to sockets with both RX and TX ring
allocated, which is probably why this was unnoticed all the time.

Signed-off-by: Phil Sutter <phil.sutter@viprinet.com>
Cc: Johann Baudy <johann.baudy@gnu-log.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

atm/iphase: rename fregt_t -> ffreg_t

[ Upstream commit ab54ee80aa7585f9666ff4dd665441d7ce41f1e8 ]

We have conflicting type qualifiers for "freg_t" in s390's ptrace.h and the
iphase atm device driver, which causes the compile error below.
Unfortunately the s390 typedef can't be renamed, since it's a user visible api,
nor can I change the include order in s390 code to avoid the conflict.

So simply rename the iphase typedef to a new name. Fixes this compile error:

In file included from drivers/atm/iphase.c:66:0:
drivers/atm/iphase.h:639:25: error: conflicting type qualifiers for 'freg_t'
In file included from next/arch/s390/include/asm/ptrace.h:9:0,
                 from next/arch/s390/include/asm/lowcore.h:12,
                 from next/arch/s390/include/asm/thread_info.h:30,
                 from include/linux/thread_info.h:54,
                 from include/linux/preempt.h:9,
                 from include/linux/spinlock.h:50,
                 from include/linux/seqlock.h:29,
                 from include/linux/time.h:5,
                 from include/linux/stat.h:18,
                 from include/linux/module.h:10,
                 from drivers/atm/iphase.c:43:
next/arch/s390/include/uapi/asm/ptrace.h:197:3: note: previous declaration of 'freg_t' was here

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: chas williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

sctp: refactor sctp_outq_teardown to insure proper re-initalization

[ Upstream commit 2f94aabd9f6c925d77aecb3ff020f1cc12ed8f86 ]

Jamie Parsons reported a problem recently, in which the re-initalization of an
association (The duplicate init case), resulted in a loss of receive window
space.  He tracked down the root cause to sctp_outq_teardown, which discarded
all the data on an outq during a re-initalization of the corresponding
association, but never reset the outq->outstanding_data field to zero.  I wrote,
and he tested this fix, which does a proper full re-initalization of the outq,
fixing this problem, and hopefully future proofing us from simmilar issues down
the road.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Jamie Parsons <Jamie.Parsons@metaswitch.com>
Tested-by: Jamie Parsons <Jamie.Parsons@metaswitch.com>
CC: Jamie Parsons <Jamie.Parsons@metaswitch.com>
CC: Vlad Yasevich <vyasevich@gmail.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: netdev@vger.kernel.org
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net: sctp: sctp_setsockopt_auth_key: use kzfree instead of kfree

[ Upstream commit 6ba542a291a5e558603ac51cda9bded347ce7627 ]

In sctp_setsockopt_auth_key, we create a temporary copy of the user
passed shared auth key for the endpoint or association and after
internal setup, we free it right away. Since it's sensitive data, we
should zero out the key before returning the memory back to the
allocator. Thus, use kzfree instead of kfree, just as we do in
sctp_auth_key_put().

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net: sctp: sctp_endpoint_free: zero out secret key data

[ Upstream commit b5c37fe6e24eec194bb29d22fdd55d73bcc709bf ]

On sctp_endpoint_destroy, previously used sensitive keying material
should be zeroed out before the memory is returned, as we already do
with e.g. auth keys when released.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tcp: frto should not set snd_cwnd to 0

[ Upstream commit 2e5f421211ff76c17130b4597bc06df4eeead24f ]

Commit 9dc274151a548 (tcp: fix ABC in tcp_slow_start())
uncovered a bug in FRTO code :
tcp_process_frto() is setting snd_cwnd to 0 if the number
of in flight packets is 0.

As Neal pointed out, if no packet is in flight we lost our
chance to disambiguate whether a loss timeout was spurious.

We should assume it was a proper loss.

Reported-by: Pasi Kärkkäinen <pasik@iki.fi>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tcp: fix for zero packets_in_flight was too broad

[ Upstream commit 6731d2095bd4aef18027c72ef845ab1087c3ba63 ]

There are transients during normal FRTO procedure during which
the packets_in_flight can go to zero between write_queue state
updates and firing the resulting segments out. As FRTO processing
occurs during that window the check must be more precise to
not match "spuriously" :-). More specificly, e.g., when
packets_in_flight is zero but FLAG_DATA_ACKED is true the problematic
branch that set cwnd into zero would not be taken and new segments
might be sent out later.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Tested-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tcp: fix MSG_SENDPAGE_NOTLAST logic

[ Upstream commit ae62ca7b03217be5e74759dc6d7698c95df498b3 ]

commit 35f9c09fe9c72e (tcp: tcp_sendpages() should call tcp_push() once)
added an internal flag : MSG_SENDPAGE_NOTLAST meant to be set on all
frags but the last one for a splice() call.

The condition used to set the flag in pipe_to_sendpage() relied on
splice() user passing the exact number of bytes present in the pipe,
or a smaller one.

But some programs pass an arbitrary high value, and the test fails.

The effect of this bug is a lack of tcp_push() at the end of a
splice(pipe -> socket) call, and possibly very slow or erratic TCP
sessions.

We should both test sd->total_len and fact that another fragment
is in the pipe (pipe->nrbufs > 1)

Many thanks to Willy for providing very clear bug report, bisection
and test programs.

Reported-by: Willy Tarreau <w@1wt.eu>
Bisected-by: Willy Tarreau <w@1wt.eu>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

bridge: Pull ip header into skb->data before looking into ip header.

[ Upstream commit 6caab7b0544e83e6c160b5e80f5a4a7dd69545c7 ]

If lower layer driver leaves the ip header in the skb fragment, it needs to
be first pulled into skb->data before inspecting ip header length or ip version
number.

Signed-off-by: Sarveshwar Bandi <sarveshwar.bandi@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tg3: Avoid null pointer dereference in tg3_interrupt in netconsole mode

[ Upstream commit 9c13cb8bb477a83b9a3c9e5a5478a4e21294a760 ]

When netconsole is enabled, logging messages generated during tg3_open
can result in a null pointer dereference for the uninitialized tg3
status block. Use the irq_sync flag to disable polling in the early
stages. irq_sync is cleared when the driver is enabling interrupts after
all initialization is completed.

Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tg3: Fix crc errors on jumbo frame receive

[ Upstream commit daf3ec688e057f6060fb9bb0819feac7a8bbf45c ]

TG3_PHY_AUXCTL_SMDSP_ENABLE/DISABLE macros do a blind write to the phy
auxiliary control register and overwrite the EXT_PKT_LEN (bit 14) resulting
in intermittent crc errors on jumbo frames with some link partners. Change
the code to do a read/modify/write.

Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

xen/netback: shutdown the ring if it contains garbage.

[ Upstream commit 48856286b64e4b66ec62b94e504d0b29c1ade664 ]

A buggy or malicious frontend should not be able to confuse netback.
If we spot anything which is not as it should be then shutdown the
device and don't try to continue with the ring in a potentially
hostile state. Well behaved and non-hostile frontends will not be
penalised.

As well as making the existing checks for such errors fatal also add a
new check that ensures that there isn't an insane number of requests
on the ring (i.e. more than would fit in the ring). If the ring
contains garbage then previously is was possible to loop over this
insane number, getting an error each time and therefore not generating
any more pending requests and therefore not exiting the loop in
xen_netbk_tx_build_gops for an externded period.

Also turn various netdev_dbg calls which no precipitate a fatal error
into netdev_err, they are rate limited because the device is shutdown
afterwards.

This fixes at least one known DoS/softlockup of the backend domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

xen/netback: don't leak pages on failure in xen_netbk_tx_check_gop.

[ Upstream commit 7d5145d8eb2b9791533ffe4dc003b129b9696c48 ]

Signed-off-by: Matthew Daley <mattjd@gmail.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

xen/netback: free already allocated memory on failure in xen_netbk_get_requests

[ Upstream commit 4cc7c1cb7b11b6f3515bd9075527576a1eecc4aa ]

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

netback: correct netbk_tx_err to handle wrap around.

[ Upstream commit b9149729ebdcfce63f853aa54a404c6a8f6ebbf3 ]

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>