Merge tag 'mac80211-for-net-2020-10-30' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211



Johannes Berg says:

====================
A couple of fixes, for
 * HE on 2.4 GHz
 * a few issues syzbot found, but we have many more reports :-(
 * a regression in nl80211-transported EAPOL frames which had
   affected a number of users, from Mathy
 * kernel-doc markings in mac80211, from Mauro
 * a format argument in reg.c, from Ye Bin
====================

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Incorrect netlink report logic in flowtable and genID.

2) Add a selftest to check that wireguard passes the right sk
   to ip_route_me_harder, from Jason A. Donenfeld.

3) Pass the actual sk to ip_route_me_harder(), also from Jason.

4) Missing expression validation of updates via nft --check.

5) Update byte and packet counters regardless of whether they
   match, from Stefano Brivio.
====================

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The tunnel device such as vxlan, bareudp and geneve in the lwt mode set
the outer df only based TUNNEL_DONT_FRAGMENT.
And this was also the behavior for gre device before switching to use
ip_md_tunnel_xmit in commit 962924fa ("ip_gre: Refactor collect
metatdata mode tunnel xmit to ip_md_tunnel_xmit")

When the ip_gre in lwt mode xmit with ip_md_tunnel_xmi changed the rule and
make the discrepancy between handling of DF by different tunnels. So in the
ip_md_tunnel_xmit should follow the same rule like other tunnels.

Fixes: cfc7381b

 ("ip_tunnel: add collect_md mode to IPIP tunnel")
Signed-off-by: wenxu <wenxu@ucloud.cn>
Link: https://lore.kernel.org/r/1604028728-31100-1-git-send-email-wenxu@ucloud.cn


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In my test setup, I had a SAMA5D27 device configured with ip forwarding, and
second device with usb ethernet (r8152) sending ICMP packets.  If the packet
was larger than about 220 bytes, the SAMA5 device would "oops" with the
following trace:

kernel BUG at net/core/skbuff.c:1863!
Internal error: Oops - BUG: 0 [#1] ARM
Modules linked in: xt_MASQUERADE ppp_async ppp_generic slhc iptable_nat xt_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 can_raw can bridge stp llc ipt_REJECT nf_reject_ipv4 sd_mod cdc_ether usbnet usb_storage r8152 scsi_mod mii o
ption usb_wwan usbserial micrel macb at91_sama5d2_adc phylink gpio_sama5d2_piobu m_can_platform m_can industrialio_triggered_buffer kfifo_buf of_mdio can_dev fixed_phy sdhci_of_at91 sdhci_pltfm libphy sdhci mmc_core ohci_at91 ehci_atmel o
hci_hcd iio_rescale industrialio sch_fq_codel spidev prox2_hal(O)
CPU: 0 PID: 0 Comm: swapper Tainted: G           O      5.9.1-prox2+ #1
Hardware name: Atmel SAMA5
PC is at skb_put+0x3c/0x50
LR is at macb_start_xmit+0x134/0xad0 [macb]
pc : [<c05258cc>]    lr : [<bf0ea5b8>]    psr: 20070113
sp : c0d01a60  ip : c07232c0  fp : c4250000
r10: c0d03cc8  r9 : 00000000  r8 : c0d038c0
r7 : 00000000  r6 : 00000008  r5 : c59b66c0  r4 : 0000002a
r3 : 8f659eff  r2 : c59e9eea  r1 : 00000001  r0 : c59b66c0
Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 10c53c7d  Table: 2640c059  DAC: 00000051
Process swapper (pid: 0, stack limit = 0x75002d81)

<snipped stack>

[<c05258cc>] (skb_put) from [<bf0ea5b8>] (macb_start_xmit+0x134/0xad0 [macb])
[<bf0ea5b8>] (macb_start_xmit [macb]) from [<c053e504>] (dev_hard_start_xmit+0x90/0x11c)
[<c053e504>] (dev_hard_start_xmit) from [<c0571180>] (sch_direct_xmit+0x124/0x260)
[<c0571180>] (sch_direct_xmit) from [<c053eae4>] (__dev_queue_xmit+0x4b0/0x6d0)
[<c053eae4>] (__dev_queue_xmit) from [<c05a5650>] (ip_finish_output2+0x350/0x580)
[<c05a5650>] (ip_finish_output2) from [<c05a7e24>] (ip_output+0xb4/0x13c)
[<c05a7e24>] (ip_output) from [<c05a39d0>] (ip_forward+0x474/0x500)
[<c05a39d0>] (ip_forward) from [<c05a13d8>] (ip_sublist_rcv_finish+0x3c/0x50)
[<c05a13d8>] (ip_sublist_rcv_finish) from [<c05a19b8>] (ip_sublist_rcv+0x11c/0x188)
[<c05a19b8>] (ip_sublist_rcv) from [<c05a2494>] (ip_list_rcv+0xf8/0x124)
[<c05a2494>] (ip_list_rcv) from [<c05403c4>] (__netif_receive_skb_list_core+0x1a0/0x20c)
[<c05403c4>] (__netif_receive_skb_list_core) from [<c05405c4>] (netif_receive_skb_list_internal+0x194/0x230)
[<c05405c4>] (netif_receive_skb_list_internal) from [<c0540684>] (gro_normal_list.part.0+0x14/0x28)
[<c0540684>] (gro_normal_list.part.0) from [<c0541280>] (napi_complete_done+0x16c/0x210)
[<c0541280>] (napi_complete_done) from [<bf14c1c0>] (r8152_poll+0x684/0x708 [r8152])
[<bf14c1c0>] (r8152_poll [r8152]) from [<c0541424>] (net_rx_action+0x100/0x328)
[<c0541424>] (net_rx_action) from [<c01012ec>] (__do_softirq+0xec/0x274)
[<c01012ec>] (__do_softirq) from [<c012d6d4>] (irq_exit+0xcc/0xd0)
[<c012d6d4>] (irq_exit) from [<c0160960>] (__handle_domain_irq+0x58/0xa4)
[<c0160960>] (__handle_domain_irq) from [<c0100b0c>] (__irq_svc+0x6c/0x90)
Exception stack(0xc0d01ef0 to 0xc0d01f38)
1ee0:                                     00000000 0000003d 0c31f383 c0d0fa00
1f00: c0d2eb80 00000000 c0d2e630 4dad8c49 4da967b0 0000003d 0000003d 00000000
1f20: fffffff5 c0d01f40 c04e0f88 c04e0f8c 30070013 ffffffff
[<c0100b0c>] (__irq_svc) from [<c04e0f8c>] (cpuidle_enter_state+0x7c/0x378)
[<c04e0f8c>] (cpuidle_enter_state) from [<c04e12c4>] (cpuidle_enter+0x28/0x38)
[<c04e12c4>] (cpuidle_enter) from [<c014f710>] (do_idle+0x194/0x214)
[<c014f710>] (do_idle) from [<c014fa50>] (cpu_startup_entry+0xc/0x14)
[<c014fa50>] (cpu_startup_entry) from [<c0a00dc8>] (start_kernel+0x46c/0x4a0)
Code: e580c054 8a000002 e1a00002 e8bd8070 (e7f001f2)
---[ end trace 146c8a334115490c ]---

The solution was to force nonlinear buffers to be cloned.  This was previously
reported by Klaus Doth (https://www.spinics.net/lists/netdev/msg556937.html

)
but never formally submitted as a patch.

This is the third revision, hopefully the formatting is correct this time!

Suggested-by: Klaus Doth <krnl@doth.eu>
Fixes: 653e92a9

 ("net: macb: add support for padding and fcs computation")
Signed-off-by: Mark Deneen <mdeneen@saucontech.com>
Link: https://lore.kernel.org/r/20201030155814.622831-1-mdeneen@saucontech.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Hangbin Liu says:

====================
IPv6: reply ICMP error if fragment doesn't contain all headers

When our Engineer run latest IPv6 Core Conformance test, test v6LC.1.3.6:
First Fragment Doesn’t Contain All Headers[1] failed. The test purpose is to
verify that the node (Linux for example) should properly process IPv6 packets
that don’t include all the headers through the Upper-Layer header.

Based on RFC 8200, Section 4.5 Fragment Header

  -  If the first fragment does not include all headers through an
     Upper-Layer header, then that fragment should be discarded and
     an ICMP Parameter Problem, Code 3, message should be sent to
     the source of the fragment, with the Pointer field set to zero.

The first patch add a definition for ICMPv6 Parameter Problem, code 3.
The second patch add a check for the 1st fragment packet to make sure
Upper-Layer header exist.

[1] Page 68, v6LC.1.3.6: First Fragment Doesn’t Contain All Headers part A, B,
C and D at https://ipv6ready.org/docs/Core_Conformance_5_0_0.pdf
[2] My reproducer:

import sys, os
from scapy.all import *

def send_frag_dst_opt(src_ip6, dst_ip6):
    ip6 = IPv6(src = src_ip6, dst = dst_ip6, nh = 44)

    frag_1 = IPv6ExtHdrFragment(nh = 60, m = 1)
    dst_opt = IPv6ExtHdrDestOpt(nh = 58)

    frag_2 = IPv6ExtHdrFragment(nh = 58, offset = 4, m = 1)
    icmp_echo = ICMPv6EchoRequest(seq = 1)

    pkt_1 = ip6/frag_1/dst_opt
    pkt_2 = ip6/frag_2/icmp_echo

    send(pkt_1)
    send(pkt_2)

def send_frag_route_opt(src_ip6, dst_ip6):
    ip6 = IPv6(src = src_ip6, dst = dst_ip6, nh = 44)

    frag_1 = IPv6ExtHdrFragment(nh = 43, m = 1)
    route_opt = IPv6ExtHdrRouting(nh = 58)

    frag_2 = IPv6ExtHdrFragment(nh = 58, offset = 4, m = 1)
    icmp_echo = ICMPv6EchoRequest(seq = 2)

    pkt_1 = ip6/frag_1/route_opt
    pkt_2 = ip6/frag_2/icmp_echo

    send(pkt_1)
    send(pkt_2)

if __name__ == '__main__':
    src = sys.argv[1]
    dst = sys.argv[2]
    conf.iface = sys.argv[3]
    send_frag_dst_opt(src, dst)
    send_frag_route_opt(src, dst)
====================

Link: https://lore.kernel.org/r/20201027123313.3717941-1-liuhangbin@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Based on RFC 8200, Section 4.5 Fragment Header:

  -  If the first fragment does not include all headers through an
     Upper-Layer header, then that fragment should be discarded and
     an ICMP Parameter Problem, Code 3, message should be sent to
     the source of the fragment, with the Pointer field set to zero.

Checking each packet header in IPv6 fast path will have performance impact,
so I put the checking in ipv6_frag_rcv().

As the packet may be any kind of L4 protocol, I only checked some common
protocols' header length and handle others by (offset + 1) > skb->len.
Also use !(frag_off & htons(IP6_OFFSET)) to catch atomic fragments
(fragmented packet with only one fragment).

When send ICMP error message, if the 1st truncated fragment is ICMP message,
icmp6_send() will break as is_ineligible() return true. So I added a check
in is_ineligible() to let fragment packet with nexthdr ICMP but no ICMP header
return false.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Based on RFC7112, Section 6:

   IANA has added the following "Type 4 - Parameter Problem" message to
   the "Internet Control Message Protocol version 6 (ICMPv6) Parameters"
   registry:

      CODE     NAME/DESCRIPTION
       3       IPv6 First Fragment has incomplete IPv6 Header Chain

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The position index in leq_seq_next is not updated when the next
entry is fetched an no more entries are available. This causes
seq_file to report the following error:

"seq_file: buggy .next function lec_seq_next [lec] did not update
 position index"

Fix this by always updating the position index.

[ Note: this is an ancient 2002 bug, the sha is from the
  tglx/history repo ]

Fixes 4aea2cbff417 ("[ATM]: Move lan seq_file ops to lec.c [1/3]")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20201027114925.21843-1-colin.king@canonical.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In ip_set_match_extensions(), for sets with counters, we take care of
updating counters themselves by calling ip_set_update_counter(), and of
checking if the given comparison and values match, by calling
ip_set_match_counter() if needed.

However, if a given comparison on counters doesn't match the configured
values, that doesn't mean the set entry itself isn't matching.

This fix restores the behaviour we had before commit 4750005a


("netfilter: ipset: Fix "don't update counters" mode when counters used
at the matching"), without reintroducing the issue fixed there: back
then, mtype_data_match() first updated counters in any case, and then
took care of matching on counters.

Now, if the IPSET_FLAG_SKIP_COUNTER_UPDATE flag is set,
ip_set_update_counter() will anyway skip counter updates if desired.

The issue observed is illustrated by this reproducer:

  ipset create c hash:ip counters
  ipset add c 192.0.2.1
  iptables -I INPUT -m set --match-set c src --bytes-gt 800 -j DROP

if we now send packets from 192.0.2.1, bytes and packets counters
for the entry as shown by 'ipset list' are always zero, and, no
matter how many bytes we send, the rule will never match, because
counters themselves are not updated.

Reported-by: Mithil Mhatre <mmhatre@redhat.com>
Fixes: 4750005a

 ("netfilter: ipset: Fix "don't update counters" mode when counters used at the matching")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Commit 0366f7e0 ("net: stmmac: add ethtool support for get/set
channels") refactored channel initialization, but during that operation,
the spinlock initialization got lost. Fix this. This fixes the following
lockdep warning:

meson8b-dwmac ff3f0000.ethernet eth0: Link is Up - 1Gbps/Full - flow control off
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 1 PID: 331 Comm: kworker/1:2H Not tainted 5.9.0-rc3+ #1858
Hardware name: Hardkernel ODROID-N2 (DT)
Workqueue: kblockd blk_mq_run_work_fn
Call trace:
 dump_backtrace+0x0/0x1d0
 show_stack+0x14/0x20
 dump_stack+0xe8/0x154
 register_lock_class+0x58c/0x590
 __lock_acquire+0x7c/0x1790
 lock_acquire+0xf4/0x440
 _raw_spin_lock_irqsave+0x80/0xb0
 stmmac_tx_timer+0x4c/0xb0 [stmmac]
 call_timer_fn+0xc4/0x3e8
 run_timer_softirq+0x2b8/0x6c0
 efi_header_end+0x114/0x5f8
 irq_exit+0x104/0x110
 __handle_domain_irq+0x60/0xb8
 gic_handle_irq+0x58/0xb0
 el1_irq+0xbc/0x180
 _raw_spin_unlock_irqrestore+0x48/0x90
 mmc_blk_rw_wait+0x70/0x160
 mmc_blk_mq_issue_rq+0x510/0x830
 mmc_mq_queue_rq+0x13c/0x278
 blk_mq_dispatch_rq_list+0x2a0/0x698
 __blk_mq_do_dispatch_sched+0x254/0x288
 __blk_mq_sched_dispatch_requests+0x190/0x1d8
 blk_mq_sched_dispatch_requests+0x34/0x70
 __blk_mq_run_hw_queue+0xcc/0x148
 blk_mq_run_work_fn+0x20/0x28
 process_one_work+0x2a8/0x718
 worker_thread+0x48/0x460
 kthread+0x134/0x160
 ret_from_fork+0x10/0x1c

Fixes: 0366f7e0

 ("net: stmmac: add ethtool support for get/set channels")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20201029185011.4749-1-m.szyprowski@samsung.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The commit "stmmac: intel: Adding ref clock 1us tic for LPI cntr"
introduced a regression which leads to the kernel panic duing loading
of the dwmac_intel module.

Move the code block after pci resources is obtained.

Fixes: b4c5f83a

 ("stmmac: intel: Adding ref clock 1us tic for LPI cntr")
Cc: Voon Weifeng <weifeng.voon@intel.com>
Signed-off-by: Wong Vee Khee <vee.khee.wong@intel.com>
Link: https://lore.kernel.org/r/20201029093228.1741-1-vee.khee.wong@intel.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When PTP timestamping is enabled on Tx, the controller
inserts the Tx timestamp at the beginning of the frame
buffer, between SFD and the L2 frame header. This means
that the skb provided by the stack is required to have
enough headroom otherwise a new skb needs to be created
by the driver to accommodate the timestamp inserted by h/w.
Up until now the driver was relying on the second option,
using skb_realloc_headroom() to create a new skb to accommodate
PTP frames. Turns out that this method is not reliable, as
reallocation of skbs for PTP frames along with the required
overhead (skb_set_owner_w, consume_skb) is causing random
crashes in subsequent skb_*() calls, when multiple concurrent
TCP streams are run at the same time on the same device
(as seen in James' report).
Note that these crashes don't occur with a single TCP stream,
nor with multiple concurrent UDP streams, but only when multiple
TCP streams are run concurrently with the PTP packet flow
(doing skb reallocation).
This patch enforces the first method, by requesting enough
headroom from the stack to accommodate PTP frames, and so avoiding
skb_realloc_headroom() & co, and the crashes no longer occur.
There's no reason not to set needed_headroom to a large enough
value to accommodate PTP frames, so in this regard this patch
is a fix.

Reported-by: James Jurack <james.jurack@ametek.com>
Fixes: bee9e58c

 ("gianfar:don't add FCB length to hard_header_len")
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Link: https://lore.kernel.org/r/20201020173605.1173-1-claudiu.manoil@nxp.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When PTP timestamping is enabled on Tx, the controller
inserts the Tx timestamp at the beginning of the frame
buffer, between SFD and the L2 frame header.  This means
that the skb provided by the stack is required to have
enough headroom otherwise a new skb needs to be created
by the driver to accommodate the timestamp inserted by h/w.
Up until now the driver was relying on skb_realloc_headroom()
to create new skbs to accommodate PTP frames.  Turns out that
this method is not reliable in this context at least, as
skb_realloc_headroom() for PTP frames can cause random crashes,
mostly in subsequent skb_*() calls, when multiple concurrent
TCP streams are run at the same time with the PTP flow
on the same device (as seen in James' report).  I also noticed
that when the system is loaded by sending multiple TCP streams,
the driver receives cloned skbs in large numbers.
skb_cow_head() instead proves to be stable in this scenario,
and not only handles cloned skbs too but it's also more efficient
and widely used in other drivers.
The commit introducing skb_realloc_headroom in the driver
goes back to 2009, commit 93c1285c
("gianfar: reallocate skb when headroom is not enough for fcb").
For practical purposes I'm referencing a newer commit (from 2012)
that brings the code to its current structure (and fixes the PTP
case).

Fixes: 9c4886e5

 ("gianfar: Fix invalid TX frames returned on error queue when time stamping")
Reported-by: James Jurack <james.jurack@ametek.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Link: https://lore.kernel.org/r/20201029081057.8506-1-claudiu.manoil@nxp.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Some (apparently older) versions of the FEC hardware block do not like
the MMFR register being cleared to avoid generation of MII events at
initialization time. The action of clearing this register results in no
future MII events being generated at all on the problem block. This means
the probing of the MDIO bus will find no PHYs.

Create a quirk that can be checked at the FECs MII init time so that
the right thing is done. The quirk is set as appropriate for the FEC
hardware blocks that are known to need this.

Fixes: f166f890

 ("net: ethernet: fec: Replace interrupt driven MDIO with polled IO")
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
Acked-by: Fugang Duan <fugand.duan@nxp.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Link: https://lore.kernel.org/r/20201028052232.1315167-1-gerg@linux-m68k.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

ip6_tnl_encap assigns to proto transport protocol which
encapsulates inner packet, but we must pass to set_inner_ipproto
protocol of that inner packet.

Calling set_inner_ipproto after ip6_tnl_encap might break gso.
For example, in case of encapsulating ipv6 packet in fou6 packet, inner_ipproto
would be set to IPPROTO_UDP instead of IPPROTO_IPV6. This would lead to
incorrect calling sequence of gso functions:
ipv6_gso_segment -> udp6_ufo_fragment -> skb_udp_tunnel_segment -> udp6_ufo_fragment
instead of:
ipv6_gso_segment -> udp6_ufo_fragment -> skb_udp_tunnel_segment -> ip6ip6_gso_segment

Fixes: 6c11fbf9

 ("ip6_tunnel: add MPLS transmit support")
Signed-off-by: Alexander Ovechkin <ovov@yandex-team.ru>
Link: https://lore.kernel.org/r/20201029171012.20904-1-ovov@yandex-team.ru


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

If userspace does not include the trailing end of batch message, then
nfnetlink aborts the transaction. This allows to check that ruleset
updates trigger no errors.

After this patch, invoking this command from the prerouting chain:

 # nft -c add rule x y fib saddr . oif type local

fails since oif is not supported there.

This patch fixes the lack of rule validation from the abort/check path
to catch configuration errors such as the one above.

Fixes: a654de8f

 ("netfilter: nf_tables: fix chain dependency validation")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

If netfilter changes the packet mark when mangling, the packet is
rerouted using the route_me_harder set of functions. Prior to this
commit, there's one big difference between route_me_harder and the
ordinary initial routing functions, described in the comment above
__ip_queue_xmit():

   /* Note: skb->sk can be different from sk, in case of tunnels */
   int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,

That function goes on to correctly make use of sk->sk_bound_dev_if,
rather than skb->sk->sk_bound_dev_if. And indeed the comment is true: a
tunnel will receive a packet in ndo_start_xmit with an initial skb->sk.
It will make some transformations to that packet, and then it will send
the encapsulated packet out of a *new* socket. That new socket will
basically always have a different sk_bound_dev_if (otherwise there'd be
a routing loop). So for the purposes of routing the encapsulated packet,
the routing information as it pertains to the socket should come from
that socket's sk, rather than the packet's original skb->sk. For that
reason __ip_queue_xmit() and related functions all do the right thing.

One might argue that all tunnels should just call skb_orphan(skb) before
transmitting the encapsulated packet into the new socket. But tunnels do
*not* do this -- and this is wisely avoided in skb_scrub_packet() too --
because features like TSQ rely on skb->destructor() being called when
that buffer space is truely available again. Calling skb_orphan(skb) too
early would result in buffers filling up unnecessarily and accounting
info being all wrong. Instead, additional routing must take into account
the new sk, just as __ip_queue_xmit() notes.

So, this commit addresses the problem by fishing the correct sk out of
state->sk -- it's already set properly in the call to nf_hook() in
__ip_local_out(), which receives the sk as part of its normal
functionality. So we make sure to plumb state->sk through the various
route_me_harder functions, and then make correct use of it following the
example of __ip_queue_xmit().

Fixes: 1da177e4

 ("Linux-2.6.12-rc2")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

If netfilter changes the packet mark, the packet is rerouted. The
ip_route_me_harder family of functions fails to use the right sk, opting
to instead use skb->sk, resulting in a routing loop when used with
tunnels. With the next change fixing this issue in netfilter, test for
the relevant condition inside our test suite, since wireguard was where
the bug was discovered.

Reported-by: Chen Minqiang <ptpt52@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

The netlink report should be sent regardless the available listeners.

Fixes: 84d7fce6 ("netfilter: nf_tables: export rule-set generation ID")
Fixes: 3b49e2e9

 ("netfilter: nf_tables: add flow table netlink frontend")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

After the previous similar bugfix there was another bug here,
if no VHT elements were found we also disabled HE. Fix this to
disable HE only on the 5 GHz band; on 6 GHz it was already not
disabled, and on 2.4 GHz there need (should) not be any VHT.

Fixes: 57fa5e85 ("mac80211: determine chandef from HE 6 GHz operation")
Link: https://lore.kernel.org/r/20201013140156.535a2fc6192f.Id6e5e525a60ac18d245d86f4015f1b271fce6ee6@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Fix follow warning:
[net/wireless/reg.c:3619]: (warning) %d in format string (no. 2)
requires 'int' but the argument type is 'unsigned int'.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Link: https://lore.kernel.org/r/20201009070215.63695-1-yebin10@huawei.com


Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Some identifiers have different names between their prototypes
and the kernel-doc markup.

Others need to be fixed, as kernel-doc markups should use this format:
        identifier - description

In the specific case of __sta_info_flush(), add a documentation
for sta_info_flush(), as this one is the one used outside
sta_info.c.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Link: https://lore.kernel.org/r/978d35eef2dc76e21c81931804e4eaefbd6d635e.1603469755.git.mchehab+huawei@kernel.org


Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When (for example) an IBSS station is pre-moved to AUTHORIZED
before it's inserted, and then the insertion fails, we don't
clean up the fast RX/TX states that might already have been
created, since we don't go through all the state transitions
again on the way down.

Do that, if it hasn't been done already, when the station is
freed. I considered only freeing the fast TX/RX state there,
but we might add more state so it's more robust to wind down
the state properly.

Note that we warn if the station was ever inserted, it should
have been properly cleaned up in that case, and the driver
will probably not like things happening out of order.

Reported-by:  <syzbot+2e293dbd67de2836ba42@syzkaller.appspotmail.com>
Link: https://lore.kernel.org/r/20201009141710.7223b322a955.I95bd08b9ad0e039c034927cce0b75beea38e059b@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>

There's a race condition in the netdev registration in that
NETDEV_REGISTER actually happens after the netdev is available,
and so if we initialize things only there, we might get called
with an uninitialized wdev through nl80211 - not using a wdev
but using a netdev interface index.

I found this while looking into a syzbot report, but it doesn't
really seem to be related, and unfortunately there's no repro
for it (yet). I can't (yet) explain how it managed to get into
cfg80211_release_pmsr() from nl80211_netlink_notify() without
the wdev having been initialized, as the latter only iterates
the wdevs that are linked into the rdev, which even without the
change here happened after init.

However, looking at this, it seems fairly clear that the init
needs to be done earlier, otherwise we might even re-init on a
netns move, when data might still be pending.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20201009135821.fdcbba3aad65.Ie9201d91dbcb7da32318812effdc1561aeaf4cdc@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When ieee80211_skb_resize() is called from ieee80211_build_hdr()
the skb has no 802.11 header yet, in fact it consist only of the
payload as the ethernet frame is removed. As such, we're using
the payload data for ieee80211_is_mgmt(), which is of course
completely wrong. This didn't really hurt us because these are
always data frames, so we could only have added more tailroom
than we needed if we determined it was a management frame and
sdata->crypto_tx_tailroom_needed_cnt was false.

However, syzbot found that of course there need not be any payload,
so we're using at best uninitialized memory for the check.

Fix this to pass explicitly the kind of frame that we have instead
of checking there, by replacing the "bool may_encrypt" argument
with an argument that can carry the three possible states - it's
not going to be encrypted, it's a management frame, or it's a data
frame (and then we check sdata->crypto_tx_tailroom_needed_cnt).

Reported-by:  <syzbot+32fd1a1bfe355e93f1e2@syzkaller.appspotmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20201009132538.e1fd7f802947.I799b288466ea2815f9d4c84349fae697dca2f189@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When sending EAPOL frames via NL80211 they are treated as injected
frames in mac80211. Due to commit 1df2bdba ("mac80211: never drop
injected frames even if normally not allowed") these injected frames
were not assigned a sta context in the function ieee80211_tx_dequeue,
causing certain wireless network cards to always send EAPOL frames in
plaintext. This may cause compatibility issues with some clients or
APs, which for instance can cause the group key handshake to fail and
in turn would cause the station to get disconnected.

This commit fixes this regression by assigning a sta context in
ieee80211_tx_dequeue to injected frames as well.

Note that sending EAPOL frames in plaintext is not a security issue
since they contain their own encryption and authentication protection.

Cc: stable@vger.kernel.org
Fixes: 1df2bdba

 ("mac80211: never drop injected frames even if normally not allowed")
Reported-by: Thomas Deutschmann <whissi@gentoo.org>
Tested-by: Christian Hesse <list@eworm.de>
Tested-by: Thomas Deutschmann <whissi@gentoo.org>
Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>
Link: https://lore.kernel.org/r/20201019160113.350912-1-Mathy.Vanhoef@kuleuven.be


Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Merge tag 'fallthrough-fixes-clang-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux

Pull fallthrough fix from Gustavo A. R. Silva:
 "This fixes a ton of fall-through warnings when building with Clang
  12.0.0 and -Wimplicit-fallthrough"

* tag 'fallthrough-fixes-clang-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
  include: jhash/signal: Fix fall-through warnings for Clang

Pull networking fixes from Jakub Kicinski:
 "Current release regressions:

   - r8169: fix forced threading conflicting with other shared
     interrupts; we tried to fix the use of raise_softirq_irqoff from an
     IRQ handler on RT by forcing hard irqs, but this driver shares
     legacy PCI IRQs so drop the _irqoff() instead

   - tipc: fix memory leak caused by a recent syzbot report fix to
     tipc_buf_append()

  Current release - bugs in new features:

   - devlink: Unlock on error in dumpit() and fix some error codes

   - net/smc: fix null pointer dereference in smc_listen_decline()

  Previous release - regressions:

   - tcp: Prevent low rmem stalls with SO_RCVLOWAT.

   - net: protect tcf_block_unbind with block lock

   - ibmveth: Fix use of ibmveth in a bridge; the self-imposed filtering
     to only send legal frames to the hypervisor was too strict

   - net: hns3: Clear the CMDQ registers before unmapping BAR region;
     incorrect cleanup order was leading to a crash

   - bnxt_en - handful of fixes to fixes:
      - Send HWRM_FUNC_RESET fw command unconditionally, even if there
        are PCIe errors being reported
      - Check abort error state in bnxt_open_nic().
      - Invoke cancel_delayed_work_sync() for PFs also.
      - Fix regression in workqueue cleanup logic in bnxt_remove_one().

   - mlxsw: Only advertise link modes supported by both driver and
     device, after removal of 56G support from the driver 56G was not
     cleared from advertised modes

   - net/smc: fix suppressed return code

  Previous release - always broken:

   - netem: fix zero division in tabledist, caused by integer overflow

   - bnxt_en: Re-write PCI BARs after PCI fatal error.

   - cxgb4: set up filter action after rewrites

   - net: ipa: command payloads already mapped

  Misc:

   - s390/ism: fix incorrect system EID, it's okay to change since it
     was added in current release

   - vsock: use ns_capable_noaudit() on socket create to suppress false
     positive audit messages"

* tag 'net-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (36 commits)
  r8169: fix issue with forced threading in combination with shared interrupts
  netem: fix zero division in tabledist
  ibmvnic: fix ibmvnic_set_mac
  mptcp: add missing memory scheduling in the rx path
  tipc: fix memory leak caused by tipc_buf_append()
  gtp: fix an use-before-init in gtp_newlink()
  net: protect tcf_block_unbind with block lock
  ibmveth: Fix use of ibmveth in a bridge.
  net/sched: act_mpls: Add softdep on mpls_gso.ko
  ravb: Fix bit fields checking in ravb_hwtstamp_get()
  devlink: Unlock on error in dumpit()
  devlink: Fix some error codes
  chelsio/chtls: fix memory leaks in CPL handlers
  chelsio/chtls: fix deadlock issue
  net: hns3: Clear the CMDQ registers before unmapping BAR region
  bnxt_en: Send HWRM_FUNC_RESET fw command unconditionally.
  bnxt_en: Check abort error state in bnxt_open_nic().
  bnxt_en: Re-write PCI BARs after PCI fatal error.
  bnxt_en: Invoke cancel_delayed_work_sync() for PFs also.
  bnxt_en: Fix regression in workqueue cleanup logic in bnxt_remove_one().
  ...

Pull rdma fixes from Jason Gunthorpe:
 "The good news is people are testing rc1 in the RDMA world - the bad
  news is testing of the for-next area is not as good as I had hoped, as
  we really should have caught at least the rdma_connect_locked() issue
  before now.

  Notable merge window regressions that didn't get caught/fixed in time
  for rc1:

   - Fix in kernel users of rxe, they were broken by the rapid fix to
     undo the uABI breakage in rxe from another patch

   - EFA userspace needs to read the GID table but was broken with the
     new GID table logic

   - Fix user triggerable deadlock in mlx5 using devlink reload

   - Fix deadlock in several ULPs using rdma_connect from the CM handler
     callbacks

   - Memory leak in qedr"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  RDMA/qedr: Fix memory leak in iWARP CM
  RDMA: Add rdma_connect_locked()
  RDMA/uverbs: Fix false error in query gid IOCTL
  RDMA/mlx5: Fix devlink deadlock on net namespace deletion
  RDMA/rxe: Fix small problem in network_type patch

As reported by Serge flag IRQF_NO_THREAD causes an error if the
interrupt is actually shared and the other driver(s) don't have this
flag set. This situation can occur if a PCI(e) legacy interrupt is
used in combination with forced threading.
There's no good way to deal with this properly, therefore we have to
remove flag IRQF_NO_THREAD. For fixing the original forced threading
issue switch to napi_schedule().

Fixes: 424a646e ("r8169: fix operation under forced interrupt threading")
Link: https://www.spinics.net/lists/netdev/msg694960.html


Reported-by: Serge Belyshev <belyshev@depni.sinp.msu.ru>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Tested-by: Serge Belyshev <belyshev@depni.sinp.msu.ru>
Link: https://lore.kernel.org/r/b5b53bfe-35ac-3768-85bf-74d1290cf394@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Currently it is possible to craft a special netlink RTM_NEWQDISC
command that can result in jitter being equal to 0x80000000. It is
enough to set the 32 bit jitter to 0x02000000 (it will later be
multiplied by 2^6) or just set the 64 bit jitter via
TCA_NETEM_JITTER64. This causes an overflow during the generation of
uniformly distributed numbers in tabledist(), which in turn leads to
division by zero (sigma != 0, but sigma * 2 is 0).

The related fragment of code needs 32-bit division - see commit
9b0ed89 ("netem: remove unnecessary 64 bit modulus"), so switching to
64 bit is not an option.

Fix the issue by keeping the value of jitter within the range that can
be adequately handled by tabledist() - [0;INT_MAX]. As negative std
deviation makes no sense, take the absolute value of the passed value
and cap it at INT_MAX. Inside tabledist(), switch to unsigned 32 bit
arithmetic in order to prevent overflows.

Fixes: 1da177e4

 ("Linux-2.6.12-rc2")
Signed-off-by: Aleksandr Nogikh <nogikh@google.com>
Reported-by:  <syzbot+ec762a6342ad0d3c0d8f@syzkaller.appspotmail.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Link: https://lore.kernel.org/r/20201028170731.1383332-1-aleksandrnogikh@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Jakub Kicinski brought up a concern in ibmvnic_set_mac().
ibmvnic_set_mac() does this:

	ether_addr_copy(adapter->mac_addr, addr->sa_data);
	if (adapter->state != VNIC_PROBED)
		rc = __ibmvnic_set_mac(netdev, addr->sa_data);

So if state == VNIC_PROBED, the user can assign an invalid address to
adapter->mac_addr, and ibmvnic_set_mac() will still return 0.

The fix is to validate ethernet address at the beginning of
ibmvnic_set_mac(), and move the ether_addr_copy to
the case of "adapter->state != VNIC_PROBED".

Fixes: c26eba03

 ("ibmvnic: Update reset infrastructure to support tunable parameters")
Signed-off-by: Lijun Pan <ljp@linux.ibm.com>
Link: https://lore.kernel.org/r/20201027220456.71450-1-ljp@linux.ibm.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When moving the skbs from the subflow into the msk receive
queue, we must schedule there the required amount of memory.

Try to borrow the required memory from the subflow, if needed,
so that we leverage the existing TCP heuristic.

Fixes: 6771bfd9

 ("mptcp: update mptcp ack sequence from work queue")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Link: https://lore.kernel.org/r/f6143a6193a083574f11b00dbf7b5ad151bc4ff4.1603810630.git.pabeni@redhat.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In preparation to enable -Wimplicit-fallthrough for Clang, explicitly
add break statements instead of letting the code fall through to the
next case.

This patch adds four break statements that, together, fix almost 40,000
warnings when building Linux 5.10-rc1 with Clang 12.0.0 and this[1] change
reverted. Notice that in order to enable -Wimplicit-fallthrough for Clang,
such change[1] is meant to be reverted at some point. So, this patch helps
to move in that direction.

Something important to mention is that there is currently a discrepancy
between GCC and Clang when dealing with switch fall-through to empty case
statements or to cases that only contain a break/continue/return
statement[2][3][4].

Now that the -Wimplicit-fallthrough option has been globally enabled[5],
any compiler should really warn on missing either a fallthrough annotation
or any of the other case-terminating statements (break/continue/return/
goto) when falling through to the next case statement. Making exceptions
to this introduces variation in case handling which may continue to lead
to bugs, misunderstandings, and a general lack of robustness. The point
of enabling options like -Wimplicit-fallthrough is to prevent human error
and aid developers in spotting bugs before their code is even built/
submitted/committed, therefore eliminating classes of bugs. So, in order
to really accomplish this, we should, and can, move in the direction of
addressing any error-prone scenarios and get rid of the unintentional
fallthrough bug-class in the kernel, entirely, even if there is some minor
redundancy. Better to have explicit case-ending statements than continue to
have exceptions where one must guess as to the right result. The compiler
will eliminate any actual redundancy.

[1] commit e2079e93 ("kbuild: Do not enable -Wimplicit-fallthrough for clang for now")
[2] https://github.com/ClangBuiltLinux/linux/issues/636
[3] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91432
[4] https://godbolt.org/z/xgkvIh
[5] commit a035d552

 ("Makefile: Globally enable fall-through warning")

Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Pull AFS fixes from David Howells:

 - Fix copy_file_range() to an afs file now returning EINVAL if the
   splice_write file op isn't supplied.

 - Fix a deref-before-check in afs_unuse_cell().

 - Fix a use-after-free in afs_xattr_get_acl().

 - Fix afs to not try to clear PG_writeback when laundering a page.

 - Fix afs to take a ref on a page that it sets PG_private on and to
   drop that ref when clearing PG_private. This is done through recently
   added helpers.

 - Fix a page leak if write_begin() fails.

 - Fix afs_write_begin() to not alter the dirty region info stored in
   page->private, but rather do this in afs_write_end() instead when we
   know what we actually changed.

 - Fix afs_invalidatepage() to alter the dirty region info on a page
   when partial page invalidation occurs so that we don't inadvertantly
   include a span of zeros that will get written back if a page gets
   laundered due to a remote 3rd-party induced invalidation.

   We mustn't, however, reduce the dirty region if the page has been
   seen to be mapped (ie. we got called through the page_mkwrite vector)
   as the page might still be mapped and we might lose data if the file
   is extended again.

 - Fix the dirty region info to have a lower resolution if the size of
   the page is too large for this to be encoded (e.g. powerpc32 with 64K
   pages).

   Note that this might not be the ideal way to handle this, since it
   may allow some leakage of undirtied zero bytes to the server's copy
   in the case of a 3rd-party conflict.

To aid the last two fixes, two additional changes:

 - Wrap the manipulations of the dirty region info stored in
   page->private into helper functions.

 - Alter the encoding of the dirty region so that the region bounds can
   be stored with one fewer bit, making a bit available for the
   indication of mappedness.

* tag 'afs-fixes-20201029' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Fix dirty-region encoding on ppc32 with 64K pages
  afs: Fix afs_invalidatepage to adjust the dirty region
  afs: Alter dirty range encoding in page->private
  afs: Wrap page->private manipulations in inline functions
  afs: Fix where page->private is set during write
  afs: Fix page leak on afs_write_begin() failure
  afs: Fix to take ref on page when PG_private is set
  afs: Fix afs_launder_page to not clear PG_writeback
  afs: Fix a use after free in afs_xattr_get_acl()
  afs: Fix tracing deref-before-check
  afs: Fix copy_file_range()

Commit ed42989e ("tipc: fix the skb_unshare() in tipc_buf_append()")
replaced skb_unshare() with skb_copy() to not reduce the data reference
counter of the original skb intentionally. This is not the correct
way to handle the cloned skb because it causes memory leak in 2
following cases:
 1/ Sending multicast messages via broadcast link
  The original skb list is cloned to the local skb list for local
  destination. After that, the data reference counter of each skb
  in the original list has the value of 2. This causes each skb not
  to be freed after receiving ACK:
  tipc_link_advance_transmq()
  {
   ...
   /* release skb */
   __skb_unlink(skb, &l->transmq);
   kfree_skb(skb); <-- memory exists after being freed
  }

 2/ Sending multicast messages via replicast link
  Similar to the above case, each skb cannot be freed after purging
  the skb list:
  tipc_mcast_xmit()
  {
   ...
   __skb_queue_purge(pkts); <-- memory exists after being freed
  }

This commit fixes this issue by using skb_unshare() instead. Besides,
to avoid use-after-free error reported by KASAN, the pointer to the
fragment is set to NULL before calling skb_unshare() to make sure that
the original skb is not freed after freeing the fragment 2 times in
case skb_unshare() returns NULL.

Fixes: ed42989e

 ("tipc: fix the skb_unshare() in tipc_buf_append()")
Acked-by: Jon Maloy <jmaloy@redhat.com>
Reported-by: Thang Hoang Ngo <thang.h.ngo@dektech.com.au>
Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Link: https://lore.kernel.org/r/20201027032403.1823-1-tung.q.nguyen@dektech.com.au


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

*_pdp_find() from gtp_encap_recv() would trigger a crash when a peer
sends GTP packets while creating new GTP device.

RIP: 0010:gtp1_pdp_find.isra.0+0x68/0x90 [gtp]
<SNIP>
Call Trace:
 <IRQ>
 gtp_encap_recv+0xc2/0x2e0 [gtp]
 ? gtp1_pdp_find.isra.0+0x90/0x90 [gtp]
 udp_queue_rcv_one_skb+0x1fe/0x530
 udp_queue_rcv_skb+0x40/0x1b0
 udp_unicast_rcv_skb.isra.0+0x78/0x90
 __udp4_lib_rcv+0x5af/0xc70
 udp_rcv+0x1a/0x20
 ip_protocol_deliver_rcu+0xc5/0x1b0
 ip_local_deliver_finish+0x48/0x50
 ip_local_deliver+0xe5/0xf0
 ? ip_protocol_deliver_rcu+0x1b0/0x1b0

gtp_encap_enable() should be called after gtp_hastable_new() otherwise
*_pdp_find() will access the uninitialized hash table.

Fixes: 1e3a3abd

 ("gtp: make GTP sockets in gtp_newlink optional")
Signed-off-by: Masahiro Fujiwara <fujiwara.masahiro@gmail.com>
Link: https://lore.kernel.org/r/20201027114846.3924-1-fujiwara.masahiro@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Pull ext4 fixes from Ted Ts'o:
 "Bug fixes for the new ext4 fast commit feature, plus a fix for the
  'data=journal' bug fix.

  Also use the generic casefolding support which has now landed in
  fs/libfs.c for 5.10"

* tag 'ext4_for_linus_fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: indicate that fast_commit is available via /sys/fs/ext4/feature/...
  ext4: use generic casefolding support
  ext4: do not use extent after put_bh
  ext4: use IS_ERR() for error checking of path
  ext4: fix mmap write protection for data=journal mode
  jbd2: fix a kernel-doc markup
  ext4: use s_mount_flags instead of s_mount_state for fast commit state
  ext4: make num of fast commit blocks configurable
  ext4: properly check for dirty state in ext4_inode_datasync_dirty()
  ext4: fix double locking in ext4_fc_commit_dentry_updates()

The dirty region bounds stored in page->private on an afs page are 15 bits
on a 32-bit box and can, at most, represent a range of up to 32K within a
32K page with a resolution of 1 byte.  This is a problem for powerpc32 with
64K pages enabled.

Further, transparent huge pages may get up to 2M, which will be a problem
for the afs filesystem on all 32-bit arches in the future.

Fix this by decreasing the resolution.  For the moment, a 64K page will
have a resolution determined from PAGE_SIZE.  In the future, the page will
need to be passed in to the helper functions so that the page size can be
assessed and the resolution determined dynamically.

Note that this might not be the ideal way to handle this, since it may
allow some leakage of undirtied zero bytes to the server's copy in the case
of a 3rd-party conflict.  Fixing that would require a separately allocated
record and is a more complicated fix.

Fixes: 4343d008

 ("afs: Get rid of the afs_writeback record")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Fix afs_invalidatepage() to adjust the dirty region recorded in
page->private when truncating a page.  If the dirty region is entirely
removed, then the private data is cleared and the page dirty state is
cleared.

Without this, if the page is truncated and then expanded again by truncate,
zeros from the expanded, but no-longer dirty region may get written back to
the server if the page gets laundered due to a conflicting 3rd-party write.

It mustn't, however, shorten the dirty region of the page if that page is
still mmapped and has been marked dirty by afs_page_mkwrite(), so a flag is
stored in page->private to record this.

Fixes: 4343d008

 ("afs: Get rid of the afs_writeback record")
Signed-off-by: David Howells <dhowells@redhat.com>