writeback: Fix periodic writeback after fs mount

commit a5faeaf9109578e65e1a32e2a3e76c8b47e7dcb6 upstream.

Code in blkdev.c moves a device inode to default_backing_dev_info when
the last reference to the device is put and moves the device inode back
to its bdi when the first reference is acquired. This includes moving to
wb.b_dirty list if the device inode is dirty. The code however doesn't
setup timer to wake corresponding flusher thread and while wb.b_dirty
list is non-empty __mark_inode_dirty() will not set it up either. Thus
periodic writeback is effectively disabled until a sync(2) call which can
lead to unexpected data loss in case of crash or power failure.

Fix the problem by setting up a timer for periodic writeback in case we
add the first dirty inode to wb.b_dirty list in bdev_inode_switch_bdi().

Reported-by: Bert De Jonghe <Bert.DeJonghe@amplidata.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sparc32: vm_area_struct access for old Sun SPARCs.

upstream commit 961246b4ed8da3bcf4ee1eb9147f341013553e3c.

Commit e4c6bfd2d79d063017ab19a18915f0bc759f32d9 ("mm: rearrange
vm_area_struct for fewer cache misses") changed the layout of the
vm_area_struct structure, it broke several SPARC32 assembly routines
which used numerical constants for accessing the vm_mm field.

This patch defines the VMA_VM_MM constant to replace the immediate values.

Signed-off-by: Olivier DANET <odanet@caramail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: only apply anti-spoofing checks to not-pointopoint tunnels

[ Upstream commit 5c29fb12e8fb8a8105ea048cb160fd79a85a52bb ]

Because of commit 218774dc341f219bfcf940304a081b121a0e8099 ("ipv6: add
anti-spoofing checks for 6to4 and 6rd") the sit driver dropped packets
for 2002::/16 destinations and sources even when configured to work as a
tunnel with fixed endpoint. We may only apply the 6rd/6to4 anti-spoofing
checks if the device is not in pointopoint mode.

This was an oversight from me in the above commit, sorry.  Thanks to
Roman Mamedov for reporting this!

Reported-by: Roman Mamedov <rm@romanrm.ru>
Cc: David Miller <davem@davemloft.net>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
neighbour: fix a race in neigh_destroy()

[ Upstream commit c9ab4d85de222f3390c67aedc9c18a50e767531e ]

There is a race in neighbour code, because neigh_destroy() uses
skb_queue_purge(&neigh->arp_queue) without holding neighbour lock,
while other parts of the code assume neighbour rwlock is what
protects arp_queue

Convert all skb_queue_purge() calls to the __skb_queue_purge() variant

Use __skb_queue_head_init() instead of skb_queue_head_init()
to make clear we do not use arp_queue.lock

And hold neigh->lock in neigh_destroy() to close the race.

Reported-by: Joe Jin <joe.jin@oracle.com>
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>
x25: Fix broken locking in ioctl error paths.

[ Upstream commit 4ccb93ce7439b63c31bc7597bfffd13567fa483d ]

Two of the x25 ioctl cases have error paths that break out of the function without
unlocking the socket, leading to this warning:

================================================
[ BUG: lock held when returning to user space! ]
3.10.0-rc7+ #36 Not tainted
------------------------------------------------
trinity-child2/31407 is leaving the kernel with locks still held!
1 lock held by trinity-child2/31407:
 #0:  (sk_lock-AF_X25){+.+.+.}, at: [<ffffffffa024b6da>] x25_ioctl+0x8a/0x740 [x25]

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: Swap ver and type in pppoe_hdr

[ Upstream commit b1a5a34bd0b8767ea689e68f8ea513e9710b671e ]

Ver and type in pppoe_hdr should be swapped as defined by RFC2516
section-4.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gre: fix a regression in ioctl

[ Upstream commit 6c734fb8592f6768170e48e7102cb2f0a1bb9759 ]

When testing GRE tunnel, I got:

 # ip tunnel show
 get tunnel gre0 failed: Invalid argument
 get tunnel gre1 failed: Invalid argument

This is a regression introduced by commit c54419321455631079c7d
("GRE: Refactor GRE tunneling code.") because previously we
only check the parameters for SIOCADDTUNNEL and SIOCCHGTUNNEL,
after that commit, the check is moved for all commands.

So, just check for SIOCADDTUNNEL and SIOCCHGTUNNEL.

After this patch I got:

 # ip tunnel show
 gre0: gre/ip  remote any  local any  ttl inherit  nopmtudisc
 gre1: gre/ip  remote 192.168.122.101  local 192.168.122.45  ttl inherit

Signed-off-by: Cong Wang <amwang@redhat.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vti: remove duplicated code to fix a memory leak

[ Upstream commit ab6c7a0a43c2eaafa57583822b619b22637b49c7 ]

vti module allocates dev->tstats twice: in vti_fb_tunnel_init()
and in vti_tunnel_init(), this lead to a memory leak of
dev->tstats.

Just remove the duplicated operations in vti_fb_tunnel_init().

(candidate for -stable)

Signed-off-by: Cong Wang <amwang@redhat.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Saurabh Mohan <saurabh.mohan@vyatta.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6,mcast: always hold idev->lock before mca_lock

[ Upstream commit 8965779d2c0e6ab246c82a405236b1fb2adae6b2, with
  some bits from commit b7b1bfce0bb68bd8f6e62a28295922785cc63781
  ("ipv6: split duplicate address detection and router solicitation timer")
  to get the __ipv6_get_lladdr() used by this patch. ]

dingtianhong reported the following deadlock detected by lockdep:

 ======================================================
 [ INFO: possible circular locking dependency detected ]
 3.4.24.05-0.1-default #1 Not tainted
 -------------------------------------------------------
 ksoftirqd/0/3 is trying to acquire lock:
  (&ndev->lock){+.+...}, at: [<ffffffff8147f804>] ipv6_get_lladdr+0x74/0x120

 but task is already holding lock:
  (&mc->mca_lock){+.+...}, at: [<ffffffff8149d130>] mld_send_report+0x40/0x150

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (&mc->mca_lock){+.+...}:
        [<ffffffff810a8027>] validate_chain+0x637/0x730
        [<ffffffff810a8417>] __lock_acquire+0x2f7/0x500
        [<ffffffff810a8734>] lock_acquire+0x114/0x150
        [<ffffffff814f691a>] rt_spin_lock+0x4a/0x60
        [<ffffffff8149e4bb>] igmp6_group_added+0x3b/0x120
        [<ffffffff8149e5d8>] ipv6_mc_up+0x38/0x60
        [<ffffffff81480a4d>] ipv6_find_idev+0x3d/0x80
        [<ffffffff81483175>] addrconf_notify+0x3d5/0x4b0
        [<ffffffff814fae3f>] notifier_call_chain+0x3f/0x80
        [<ffffffff81073471>] raw_notifier_call_chain+0x11/0x20
        [<ffffffff813d8722>] call_netdevice_notifiers+0x32/0x60
        [<ffffffff813d92d4>] __dev_notify_flags+0x34/0x80
        [<ffffffff813d9360>] dev_change_flags+0x40/0x70
        [<ffffffff813ea627>] do_setlink+0x237/0x8a0
        [<ffffffff813ebb6c>] rtnl_newlink+0x3ec/0x600
        [<ffffffff813eb4d0>] rtnetlink_rcv_msg+0x160/0x310
        [<ffffffff814040b9>] netlink_rcv_skb+0x89/0xb0
        [<ffffffff813eb357>] rtnetlink_rcv+0x27/0x40
        [<ffffffff81403e20>] netlink_unicast+0x140/0x180
        [<ffffffff81404a9e>] netlink_sendmsg+0x33e/0x380
        [<ffffffff813c4252>] sock_sendmsg+0x112/0x130
        [<ffffffff813c537e>] __sys_sendmsg+0x44e/0x460
        [<ffffffff813c5544>] sys_sendmsg+0x44/0x70
        [<ffffffff814feab9>] system_call_fastpath+0x16/0x1b

 -> #0 (&ndev->lock){+.+...}:
        [<ffffffff810a798e>] check_prev_add+0x3de/0x440
        [<ffffffff810a8027>] validate_chain+0x637/0x730
        [<ffffffff810a8417>] __lock_acquire+0x2f7/0x500
        [<ffffffff810a8734>] lock_acquire+0x114/0x150
        [<ffffffff814f6c82>] rt_read_lock+0x42/0x60
        [<ffffffff8147f804>] ipv6_get_lladdr+0x74/0x120
        [<ffffffff8149b036>] mld_newpack+0xb6/0x160
        [<ffffffff8149b18b>] add_grhead+0xab/0xc0
        [<ffffffff8149d03b>] add_grec+0x3ab/0x460
        [<ffffffff8149d14a>] mld_send_report+0x5a/0x150
        [<ffffffff8149f99e>] igmp6_timer_handler+0x4e/0xb0
        [<ffffffff8105705a>] call_timer_fn+0xca/0x1d0
        [<ffffffff81057b9f>] run_timer_softirq+0x1df/0x2e0
        [<ffffffff8104e8c7>] handle_pending_softirqs+0xf7/0x1f0
        [<ffffffff8104ea3b>] __do_softirq_common+0x7b/0xf0
        [<ffffffff8104f07f>] __thread_do_softirq+0x1af/0x210
        [<ffffffff8104f1c1>] run_ksoftirqd+0xe1/0x1f0
        [<ffffffff8106c7de>] kthread+0xae/0xc0
        [<ffffffff814fff74>] kernel_thread_helper+0x4/0x10

actually we can just hold idev->lock before taking pmc->mca_lock,
and avoid taking idev->lock again when iterating idev->addr_list,
since the upper callers of mld_newpack() already take
read_lock_bh(&idev->lock).

Reported-by: dingtianhong <dingtianhong@huawei.com>
Cc: dingtianhong <dingtianhong@huawei.com>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Tested-by: Ding Tianhong <dingtianhong@huawei.com>
Tested-by: Chen Weilong <chenweilong@huawei.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ip_tunnels: Use skb-len to PMTU check.

[ Upstream commit 23a3647bc4f93bac3776c66dc2c7f7f68b3cd662 ]

In path mtu check, ip header total length works for gre device
but not for gre-tap device.  Use skb len which is consistent
for all tunneling types.  This is old bug in gre.
This also fixes mtu calculation bug introduced by
commit c54419321455631079c7d (GRE: Refactor GRE tunneling code).

Reported-by: Timo Teras <timo.teras@iki.fi>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
l2tp: add missing .owner to struct pppox_proto

[ Upstream commit e1558a93b61962710733dc8c11a2bc765607f1cd ]

Add missing .owner of struct pppox_proto. This prevents the
module from being removed from underneath its users.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipip: fix a regression in ioctl

[ Upstream commit 3b7b514f44bff05d26a6499c4d4fac2a83938e6e ]

This is a regression introduced by
commit fd58156e456d9f68fe0448 (IPIP: Use ip-tunneling code.)

Similar to GRE tunnel, previously we only check the parameters
for SIOCADDTUNNEL and SIOCCHGTUNNEL, after that commit, the
check is moved for all commands.

So, just check for SIOCADDTUNNEL and SIOCCHGTUNNEL.

Also, the check for i_key, o_key etc. is suspicious too,
which did not exist before, reset them before passing
to ip_tunnel_ioctl().

Signed-off-by: Cong Wang <amwang@redhat.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: call udp_push_pending_frames when uncorking a socket with AF_INET pending data

[ Upstream commit 8822b64a0fa64a5dd1dfcf837c5b0be83f8c05d1 ]

We accidentally call down to ip6_push_pending_frames when uncorking
pending AF_INET data on a ipv6 socket. This results in the following
splat (from Dave Jones):

skbuff: skb_under_panic: text:ffffffff816765f6 len:48 put:40 head:ffff88013deb6df0 data:ffff88013deb6dec tail:0x2c end:0xc0 dev:<NULL>
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:126!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in: dccp_ipv4 dccp 8021q garp bridge stp dlci mpoa snd_seq_dummy sctp fuse hidp tun bnep nfnetlink scsi_transport_iscsi rfcomm can_raw can_bcm af_802154 appletalk caif_socket can caif ipt_ULOG x25 rose af_key pppoe pppox ipx phonet irda llc2 ppp_generic slhc p8023 psnap p8022 llc crc_ccitt atm bluetooth
+netrom ax25 nfc rfkill rds af_rxrpc coretemp hwmon kvm_intel kvm crc32c_intel snd_hda_codec_realtek ghash_clmulni_intel microcode pcspkr snd_hda_codec_hdmi snd_hda_intel snd_hda_codec snd_hwdep usb_debug snd_seq snd_seq_device snd_pcm e1000e snd_page_alloc snd_timer ptp snd pps_core soundcore xfs libcrc32c
CPU: 2 PID: 8095 Comm: trinity-child2 Not tainted 3.10.0-rc7+ #37
task: ffff8801f52c2520 ti: ffff8801e6430000 task.ti: ffff8801e6430000
RIP: 0010:[<ffffffff816e759c>]  [<ffffffff816e759c>] skb_panic+0x63/0x65
RSP: 0018:ffff8801e6431de8  EFLAGS: 00010282
RAX: 0000000000000086 RBX: ffff8802353d3cc0 RCX: 0000000000000006
RDX: 0000000000003b90 RSI: ffff8801f52c2ca0 RDI: ffff8801f52c2520
RBP: ffff8801e6431e08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff88022ea0c800
R13: ffff88022ea0cdf8 R14: ffff8802353ecb40 R15: ffffffff81cc7800
FS:  00007f5720a10740(0000) GS:ffff880244c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000005862000 CR3: 000000022843c000 CR4: 00000000001407e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 ffff88013deb6dec 000000000000002c 00000000000000c0 ffffffff81a3f6e4
 ffff8801e6431e18 ffffffff8159a9aa ffff8801e6431e90 ffffffff816765f6
 ffffffff810b756b 0000000700000002 ffff8801e6431e40 0000fea9292aa8c0
Call Trace:
 [<ffffffff8159a9aa>] skb_push+0x3a/0x40
 [<ffffffff816765f6>] ip6_push_pending_frames+0x1f6/0x4d0
 [<ffffffff810b756b>] ? mark_held_locks+0xbb/0x140
 [<ffffffff81694919>] udp_v6_push_pending_frames+0x2b9/0x3d0
 [<ffffffff81694660>] ? udplite_getfrag+0x20/0x20
 [<ffffffff8162092a>] udp_lib_setsockopt+0x1aa/0x1f0
 [<ffffffff811cc5e7>] ? fget_light+0x387/0x4f0
 [<ffffffff816958a4>] udpv6_setsockopt+0x34/0x40
 [<ffffffff815949f4>] sock_common_setsockopt+0x14/0x20
 [<ffffffff81593c31>] SyS_setsockopt+0x71/0xd0
 [<ffffffff816f5d54>] tracesys+0xdd/0xe2
Code: 00 00 48 89 44 24 10 8b 87 d8 00 00 00 48 89 44 24 08 48 8b 87 e8 00 00 00 48 c7 c7 c0 04 aa 81 48 89 04 24 31 c0 e8 e1 7e ff ff <0f> 0b 55 48 89 e5 0f 0b 55 48 89 e5 0f 0b 55 48 89 e5 0f 0b 55
RIP  [<ffffffff816e759c>] skb_panic+0x63/0x65
 RSP <ffff8801e6431de8>

This patch adds a check if the pending data is of address family AF_INET
and directly calls udp_push_ending_frames from udp_v6_push_pending_frames
if that is the case.

This bug was found by Dave Jones with trinity.

(Also move the initialization of fl6 below the AF_INET check, even if
not strictly necessary.)

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Dave Jones <davej@redhat.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: ip6_append_data_mtu did not care about pmtudisc and frag_size

[ Upstream commit 75a493e60ac4bbe2e977e7129d6d8cbb0dd236be ]

If the socket had an IPV6_MTU value set, ip6_append_data_mtu lost track
of this when appending the second frame on a corked socket. This results
in the following splat:

[37598.993962] ------------[ cut here ]------------
[37598.994008] kernel BUG at net/core/skbuff.c:2064!
[37598.994008] invalid opcode: 0000 [#1] SMP
[37598.994008] Modules linked in: tcp_lp uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core videodev media vfat fat usb_storage fuse ebtable_nat xt_CHECKSUM bridge stp llc ipt_MASQUERADE nf_conntrack_netbios_ns nf_conntrack_broadcast ip6table_mangle ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 iptable_nat
+nf_nat_ipv4 nf_nat iptable_mangle nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ebtable_filter ebtables ip6table_filter ip6_tables be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i cxgb3 mdio libcxgbi ib_iser rdma_cm ib_addr iw_cm ib_cm ib_sa ib_mad ib_core iscsi_tcp libiscsi_tcp libiscsi
+scsi_transport_iscsi rfcomm bnep iTCO_wdt iTCO_vendor_support snd_hda_codec_conexant arc4 iwldvm mac80211 snd_hda_intel acpi_cpufreq mperf coretemp snd_hda_codec microcode cdc_wdm cdc_acm
[37598.994008]  snd_hwdep cdc_ether snd_seq snd_seq_device usbnet mii joydev btusb snd_pcm bluetooth i2c_i801 e1000e lpc_ich mfd_core ptp iwlwifi pps_core snd_page_alloc mei cfg80211 snd_timer thinkpad_acpi snd tpm_tis soundcore rfkill tpm tpm_bios vhost_net tun macvtap macvlan kvm_intel kvm uinput binfmt_misc
+dm_crypt i915 i2c_algo_bit drm_kms_helper drm i2c_core wmi video
[37598.994008] CPU 0
[37598.994008] Pid: 27320, comm: t2 Not tainted 3.9.6-200.fc18.x86_64 #1 LENOVO 27744PG/27744PG
[37598.994008] RIP: 0010:[<ffffffff815443a5>]  [<ffffffff815443a5>] skb_copy_and_csum_bits+0x325/0x330
[37598.994008] RSP: 0018:ffff88003670da18  EFLAGS: 00010202
[37598.994008] RAX: ffff88018105c018 RBX: 0000000000000004 RCX: 00000000000006c0
[37598.994008] RDX: ffff88018105a6c0 RSI: ffff88018105a000 RDI: ffff8801e1b0aa00
[37598.994008] RBP: ffff88003670da78 R08: 0000000000000000 R09: ffff88018105c040
[37598.994008] R10: ffff8801e1b0aa00 R11: 0000000000000000 R12: 000000000000fff8
[37598.994008] R13: 00000000000004fc R14: 00000000ffff0504 R15: 0000000000000000
[37598.994008] FS:  00007f28eea59740(0000) GS:ffff88023bc00000(0000) knlGS:0000000000000000
[37598.994008] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[37598.994008] CR2: 0000003d935789e0 CR3: 00000000365cb000 CR4: 00000000000407f0
[37598.994008] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[37598.994008] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[37598.994008] Process t2 (pid: 27320, threadinfo ffff88003670c000, task ffff88022c162ee0)
[37598.994008] Stack:
[37598.994008]  ffff88022e098a00 ffff88020f973fc0 0000000000000008 00000000000004c8
[37598.994008]  ffff88020f973fc0 00000000000004c4 ffff88003670da78 ffff8801e1b0a200
[37598.994008]  0000000000000018 00000000000004c8 ffff88020f973fc0 00000000000004c4
[37598.994008] Call Trace:
[37598.994008]  [<ffffffff815fc21f>] ip6_append_data+0xccf/0xfe0
[37598.994008]  [<ffffffff8158d9f0>] ? ip_copy_metadata+0x1a0/0x1a0
[37598.994008]  [<ffffffff81661f66>] ? _raw_spin_lock_bh+0x16/0x40
[37598.994008]  [<ffffffff8161548d>] udpv6_sendmsg+0x1ed/0xc10
[37598.994008]  [<ffffffff812a2845>] ? sock_has_perm+0x75/0x90
[37598.994008]  [<ffffffff815c3693>] inet_sendmsg+0x63/0xb0
[37598.994008]  [<ffffffff812a2973>] ? selinux_socket_sendmsg+0x23/0x30
[37598.994008]  [<ffffffff8153a450>] sock_sendmsg+0xb0/0xe0
[37598.994008]  [<ffffffff810135d1>] ? __switch_to+0x181/0x4a0
[37598.994008]  [<ffffffff8153d97d>] sys_sendto+0x12d/0x180
[37598.994008]  [<ffffffff810dfb64>] ? __audit_syscall_entry+0x94/0xf0
[37598.994008]  [<ffffffff81020ed1>] ? syscall_trace_enter+0x231/0x240
[37598.994008]  [<ffffffff8166a7e7>] tracesys+0xdd/0xe2
[37598.994008] Code: fe 07 00 00 48 c7 c7 04 28 a6 81 89 45 a0 4c 89 4d b8 44 89 5d a8 e8 1b ac b1 ff 44 8b 5d a8 4c 8b 4d b8 8b 45 a0 e9 cf fe ff ff <0f> 0b 66 0f 1f 84 00 00 00 00 00 66 66 66 66 90 55 48 89 e5 48
[37598.994008] RIP  [<ffffffff815443a5>] skb_copy_and_csum_bits+0x325/0x330
[37598.994008]  RSP <ffff88003670da18>
[37599.007323] ---[ end trace d69f6a17f8ac8eee ]---

While there, also check if path mtu discovery is activated for this
socket. The logic was adapted from ip6_append_data when first writing
on the corked socket.

This bug was introduced with commit
0c1833797a5a6ec23ea9261d979aa18078720b74 ("ipv6: fix incorrect ipsec
fragment").

v2:
a) Replace IPV6_PMTU_DISC_DO with IPV6_PMTUDISC_PROBE.
b) Don't pass ipv6_pinfo to ip6_append_data_mtu (suggestion by Gao
   feng, thanks!).
c) Change mtu to unsigned int, else we get a warning about
   non-matching types because of the min()-macro type-check.

Acked-by: Gao feng <gaofeng@cn.fujitsu.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: rt6_check_neigh should successfully verify neigh if no NUD information are available

[ Upstream commit 3630d40067a21d4dfbadc6002bb469ce26ac5d52 ]

After the removal of rt->n we do not create a neighbour entry at route
insertion time (rt6_bind_neighbour is gone). As long as no neighbour is
created because of "useful traffic" we skip this routing entry because
rt6_check_neigh cannot pick up a valid neighbour (neigh == NULL) and
thus returns false.

This change was introduced by commit
887c95cc1da53f66a5890fdeab13414613010097 ("ipv6: Complete neighbour
entry removal from dst_entry.")

To quote RFC4191:
"If the host has no information about the router's reachability, then
the host assumes the router is reachable."

and also:
"A host MUST NOT probe a router's reachability in the absence of useful
traffic that the host would have sent to the router if it were reachable."

So, just assume the router is reachable and let's rt6_probe do the
rest. We don't need to create a neighbour on route insertion time.

If we don't compile with CONFIG_IPV6_ROUTER_PREF (RFC4191 support)
a neighbour is only valid if its nud_state is NUD_VALID. I did not find
any references that we should probe the router on route insertion time
via the other RFCs. So skip this route in that case.

v2:
a) use IS_ENABLED instead of #ifdefs (thanks to Sergei Shtylyov)

Reported-by: Pierre Emeriaud <petrus.lt@gmail.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sfc: Fix memory leak when discarding scattered packets

[ Upstream commit 734d4e159b283a4ae4d007b7e7a91d84398ccb92 ]

Commit 2768935a4660 ('sfc: reuse pages to avoid DMA mapping/unmapping
costs') did not fully take account of DMA scattering which was
introduced immediately before.  If a received packet is invalid and
must be discarded, we only drop a reference to the first buffer's
page, but we need to drop a reference for each buffer the packet
used.

I think this bug was missed partly because efx_recycle_rx_buffers()
was not renamed and so no longer does what its name says.  It does not
change the state of buffers, but only prepares the underlying pages
for recycling.  Rename it accordingly.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/cadence/macb: fix bug/typo in extracting gem_irq_read_clear bit

[ Upstream commit 01276ed2424eb78c95461545410923d5da154d31 ]

Signed-off-by: Jongsung Kim <neidhard.kim@lge.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
virtio: support unlocked queue poll

[ Upstream commit cc229884d3f77ec3b1240e467e0236c3e0647c0c ]

This adds a way to check ring empty state after enable_cb outside any
locks. Will be used by virtio_net.

Note: there's room for more optimization: caller is likely to have a
memory barrier already, which means we might be able to get rid of a
barrier here.  Deferring this optimization until we do some
benchmarking.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
virtio_net: fix race in RX VQ processing

[ Upstream commit cbdadbbf0c790f79350a8f36029208944c5487d0 ]

virtio net called virtqueue_enable_cq on RX path after napi_complete, so
with NAPI_STATE_SCHED clear - outside the implicit napi lock.
This violates the requirement to synchronize virtqueue_enable_cq wrt
virtqueue_add_buf.  In particular, used event can move backwards,
causing us to lose interrupts.
In a debug build, this can trigger panic within START_USE.

Jason Wang reports that he can trigger the races artificially,
by adding udelay() in virtqueue_enable_cb() after virtio_mb().

However, we must call napi_complete to clear NAPI_STATE_SCHED before
polling the virtqueue for used buffers, otherwise napi_schedule_prep in
a callback will fail, causing us to lose RX events.

To fix, call virtqueue_enable_cb_prepare with NAPI_STATE_SCHED
set (under napi lock), later call virtqueue_poll with
NAPI_STATE_SCHED clear (outside the lock).

Reported-by: Jason Wang <jasowang@redhat.com>
Tested-by: Jason Wang <jasowang@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vhost-net: fix use-after-free in vhost_net_flush

[ Upstream commit c38e39c378f46f00ce922dd40a91043a9925c28d ]

vhost_net_ubuf_put_and_wait has a confusing name:
it will actually also free it's argument.
Thus since commit 1280c27f8e29acf4af2da914e80ec27c3dbd5c01
    "vhost-net: flush outstanding DMAs on memory change"
vhost_net_flush tries to use the argument after passing it
to vhost_net_ubuf_put_and_wait, this results
in use after free.
To fix, don't free the argument in vhost_net_ubuf_put_and_wait,
add an new API for callers that want to free ubufs.

Acked-by: Asias He <asias@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>