The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20200507185538.GA14674@embeddedorSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

commit cfbc6c4c ("iwlwifi: mvm: support mac80211 TXQs model")
left behind this, remove it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20200506134217.49760-1-yuehaibing@huawei.comSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

gcc-10 complains when a zero-length array is accessed:

drivers/net/wireless/intel/iwlwifi/mvm/tx.c: In function 'iwl_mvm_rx_ba_notif':
drivers/net/wireless/intel/iwlwifi/mvm/tx.c:1929:17: warning: array subscript 9 is outside the bounds of an interior zero-length array 'struct iwl_mvm_compressed_ba_tfd[0]' [-Wzero-length-bounds]
 1929 |     &ba_res->tfd[i];
      |      ~~~~~~~~~~~^~~
In file included from drivers/net/wireless/intel/iwlwifi/mvm/../fw/api/tdls.h:68,
                 from drivers/net/wireless/intel/iwlwifi/mvm/fw-api.h:68,
                 from drivers/net/wireless/intel/iwlwifi/mvm/sta.h:73,
                 from drivers/net/wireless/intel/iwlwifi/mvm/mvm.h:83,
                 from drivers/net/wireless/intel/iwlwifi/mvm/tx.c:72:
drivers/net/wireless/intel/iwlwifi/mvm/../fw/api/tx.h:769:35: note: while referencing 'tfd'
  769 |  struct iwl_mvm_compressed_ba_tfd tfd[0];
      |                                   ^~~

Change this structure to use a flexible-array member for 'tfd' instead,
along with the various structures using an zero-length ieee80211_hdr
array that do not show warnings today but might be affected by similar
issues in the future.

Fixes: 6f68cc36 ("iwlwifi: api: annotate compressed BA notif array sizes")
Fixes: c46e7724 ("iwlwifi: mvm: support new BA notification response")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200430213101.135134-3-arnd@arndb.deSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

The variable ret is being assigned with a value that is never read
and it is being updated later with a new value. The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200420222449.99481-1-colin.king@canonical.comSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

The correct variable name was replaced here by mistake by commit
ab27926d ("iwlwifi: fix devices with PCI Device ID 0x34F0 and 11ac RF
modules").
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Link: https://lore.kernel.org/r/20200210135817.31994-1-luca@lucaceresoli.netSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

On AX200, the average power was showing positive instead of negative, but
otherwise matched the expected RSSI.  Flip the value to negative before
 giving to mac80211.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Link: https://lore.kernel.org/r/20191126214744.1283-1-greearb@candelatech.com
[removed unnecessary check and some unnecessary parentheses]
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

IWL_WARN seems excessive here since this can happen during normal
operation. Every time I connect to a new network with 8086:24fd I get
this as KERN_WARNING on the console, which mildly distracts from other
more pressing messages. For example:

    % sudo journalctl _TRANSPORT=kernel | grep -c 'FW already configured'
    403
Signed-off-by: Chris Down <chris@chrisdown.name>
Cc: Shahar S Matityahu <shahar.s.matityahu@intel.com>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-wireless@vger.kernel.org
Link: https://lore.kernel.org/r/20191017144841.GA16393@chrisdown.nameSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

All iwlwifi cards below the 22000 series are able to handle multiple
keyids per STA and allow the selection of the encryption key per MPDU.

These are therefore fully compatible with the Extended Key ID support
implementation in mac80211.

Enable Extended Key ID support for all dvm cards and the mvm cards not
using the incompatible new Tx API introduced for the 22000 series.
Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
Link: https://lore.kernel.org/r/20190819180540.2855-1-alexander@wetzel-home.deSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

xdp_umem.c had overlapping changes between the 64-bit math fix
for the calculation of npgs and the removal of the zerocopy
memory type which got rid of the chunk_size_nohdr member.

The mlx5 Kconfig conflict is a case where we just take the
net-next copy of the Kconfig entry dependency as it takes on
the ESWITCH dependency by one level of indirection which is
what the 'net' conflicting change is trying to ensure.
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'mac80211-next-for-davem-2020-05-31' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next

Johannes Berg says:

====================
Another set of changes, including
 * many 6 GHz changes, though it's not _quite_ complete
   (I left out scanning for now, we're still discussing)
 * allow userspace SA-query processing for operating channel
   validation
 * TX status for control port TX, for AP-side operation
 * more per-STA/TID control options
 * move to kHz for channels, for future S1G operation
 * various other small changes
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Yes, staying withing 80 columns is certainly still _preferred_.  But
it's not the hard limit that the checkpatch warnings imply, and other
concerns can most certainly dominate.

Increase the default limit to 100 characters.  Not because 100
characters is some hard limit either, but that's certainly a "what are
you doing" kind of value and less likely to be about the occasional
slightly longer lines.

Miscellanea:

 - to avoid unnecessary whitespace changes in files, checkpatch will no
   longer emit a warning about line length when scanning files unless
   --strict is also used

 - Add a bit to coding-style about alignment to open parenthesis
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull x86 fixes from Thomas Gleixner:
 "A pile of x86 fixes:

   - Prevent a memory leak in ioperm which was caused by the stupid
     assumption that the exit cleanup is always called for current,
     which is not the case when fork fails after taking a reference on
     the ioperm bitmap.

   - Fix an arithmething overflow in the DMA code on 32bit systems

   - Fill gaps in the xstate copy with defaults instead of leaving them
     uninitialized

   - Revert: "Make __X32_SYSCALL_BIT be unsigned long" as it turned out
     that existing user space fails to build"

* tag 'x86-urgent-2020-05-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ioperm: Prevent a memory leak when fork fails
  x86/dma: Fix max PFN arithmetic overflow on 32 bit systems
  copy_xstate_to_kernel(): don't leave parts of destination uninitialized
  x86/syscalls: Revert "x86/syscalls: Make __X32_SYSCALL_BIT be unsigned long"

Pull scheduler fix from Thomas Gleixner:
 "A single scheduler fix preventing a crash in NUMA balancing.

  The current->mm check is not reliable as the mm might be temporary due
  to use_mm() in a kthread. Check for PF_KTHREAD explictly"

* tag 'sched-urgent-2020-05-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Don't NUMA balance for kthreads

Pull networking fixes from David Miller:
 "Another week, another set of bug fixes:

   1) Fix pskb_pull length in __xfrm_transport_prep(), from Xin Long.

   2) Fix double xfrm_state put in esp{4,6}_gro_receive(), also from Xin
      Long.

   3) Re-arm discovery timer properly in mac80211 mesh code, from Linus
      Lüssing.

   4) Prevent buffer overflows in nf_conntrack_pptp debug code, from
      Pablo Neira Ayuso.

   5) Fix race in ktls code between tls_sw_recvmsg() and
      tls_decrypt_done(), from Vinay Kumar Yadav.

   6) Fix crashes on TCP fallback in MPTCP code, from Paolo Abeni.

   7) More validation is necessary of untrusted GSO packets coming from
      virtualization devices, from Willem de Bruijn.

   8) Fix endianness of bnxt_en firmware message length accesses, from
      Edwin Peer.

   9) Fix infinite loop in sch_fq_pie, from Davide Caratti.

  10) Fix lockdep splat in DSA by setting lockless TX in netdev features
      for slave ports, from Vladimir Oltean.

  11) Fix suspend/resume crashes in mlx5, from Mark Bloch.

  12) Fix use after free in bpf fmod_ret, from Alexei Starovoitov.

  13) ARP retransmit timer guard uses wrong offset, from Hongbin Liu.

  14) Fix leak in inetdev_init(), from Yang Yingliang.

  15) Don't try to use inet hash and unhash in l2tp code, results in
      crashes. From Eric Dumazet"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (77 commits)
  l2tp: add sk_family checks to l2tp_validate_socket
  l2tp: do not use inet_hash()/inet_unhash()
  net: qrtr: Allocate workqueue before kernel_bind
  mptcp: remove msk from the token container at destruction time.
  mptcp: fix race between MP_JOIN and close
  mptcp: fix unblocking connect()
  net/sched: act_ct: add nat mangle action only for NAT-conntrack
  devinet: fix memleak in inetdev_init()
  virtio_vsock: Fix race condition in virtio_transport_recv_pkt
  drivers/net/ibmvnic: Update VNIC protocol version reporting
  NFC: st21nfca: add missed kfree_skb() in an error path
  neigh: fix ARP retransmit timer guard
  bpf, selftests: Add a verifier test for assigning 32bit reg states to 64bit ones
  bpf, selftests: Verifier bounds tests need to be updated
  bpf: Fix a verifier issue when assigning 32bit reg states to 64bit ones
  bpf: Fix use-after-free in fmod_ret check
  net/mlx5e: replace EINVAL in mlx5e_flower_parse_meta()
  net/mlx5e: Fix MLX5_TC_CT dependencies
  net/mlx5e: Properly set default values when disabling adaptive moderation
  net/mlx5e: Fix arch depending casting issue in FEC
  ...

With some newer AKMs, the KCK and KEK are bigger, so allow that
if the driver advertises support for it. In addition, add a new
attribute for the AKM so we can use it for offloaded rekeying.
Signed-off-by: Nathan Errera <nathan.errera@intel.com>
[reword commit message]
Link: https://lore.kernel.org/r/20200528212237.5eb58b00a5d1.I61b09d77c4f382e8d58a05dcca78096e99a6bc15@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

Set short slot also for 6 GHz band, just like 5 GHz.
Signed-off-by: Tova Mussai <tova.mussai@intel.com>
Link: https://lore.kernel.org/r/20200528213443.75f38e6f5efd.I272fbae402b03123f04e9ae69204eeab960c70cd@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

Treat it like the 5 GHz band.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Link: https://lore.kernel.org/r/20200528213443.889e5c9dd006.Id8ed3bb8000ba8738be5df05639415eb2e23c61a@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

On 6 GHz, stations don't have ht_supported set, but they can
still do aggregation since they must have HE, allow that.

Link: https://lore.kernel.org/r/20200528213443.776d3c891b64.Ifa099d450617b50c691832b3c4aa08959fab520a@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

On 6 GHz band, HE capabilities must be available for all of
the interface types, otherwise we shouldn't use 6 GHz. Check
this.

Link: https://lore.kernel.org/r/20200528213443.5881cb3c8c4a.I583b54172f91f98d44af64a16c5826fe458cbb27@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

On the 6 GHz band, HE should be used, but without any direct HT/VHT
capabilities, instead the HE 6 GHz band capabilities will capture
the relevant information. Reject HT/VHT capabilities here.

Link: https://lore.kernel.org/r/20200528213443.bfe89c35459a.Ibba5e066fa0087fd49d13cfee89d196ea0c68ae2@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

If a 6 GHz channel exists, then we can probably safely assume that
the device actually supports it, and then it should support most
bandwidths.

This will probably need to be extended to check the interface type
and then dig into the HE capabilities for that though, to have the
correct bandwidth check.

Link: https://lore.kernel.org/r/20200528213443.d4864ef52e92.I82f09b2b14a56413ce20376d09967fe954a033eb@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

On 6 GHz, the 6 GHz capabilities element should be added, do that.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
[add commit message]
Link: https://lore.kernel.org/r/20200528213443.8ee764f0cde0.I2b0c66b60e11818c97c9803e04a6a197c6376243@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

In order to handle 6 GHz AP side, take the HE 6 GHz band capability
data and pass it to the driver (which needs it for A-MPDU spacing
and A-MPDU length).

Link: https://lore.kernel.org/r/1589399105-25472-6-git-send-email-rmanohar@codeaurora.orgCo-developed-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Signed-off-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Link: https://lore.kernel.org/r/20200528213443.784e4890d82f.I5f1230d5ab27e84e7bbe88e3645b24ea15a0c146@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

An AP supporting EMA (Enhanced Multi-BSSID advertisement) should set
bit 83 in the extended capabilities IE (9.4.2.26 in the 802.11ax D5 spec).
So the *3rd* bit of the 10th byte should be checked.
Also, in one place, the wrong byte was checked.
(cfg80211_find_ie returns a pointer to the beginning of the IE,
 so the data really starts at ie[2], so the 10th byte
 should be ie[12]. To avoid this confusion, use cfg80211_find_elem
 instead).
Signed-off-by: Shaul Triebitz <shaul.triebitz@intel.com>
Link: https://lore.kernel.org/r/20200528213443.4316121fa2a3.I9745582f8d41ad8e689dac0fefcd70b276d7c1ea@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

Support connecting to HE 6 GHz APs and mesh networks on 6 GHz,
where the HT/VHT information is missing but instead the HE 6 GHz
band capability is present, and the 6 GHz Operation information
field is used to encode the channel configuration instead of the
HT/VHT operation elements.

Also add some other bits needed to connect to 6 GHz networks.

Link: https://lore.kernel.org/r/1589399105-25472-10-git-send-email-rmanohar@codeaurora.orgCo-developed-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Signed-off-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Link: https://lore.kernel.org/r/20200528213443.25687d2695bc.I3f9747c1147480f65445f13eda5c4a5ed4e86757@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

If the AP advertises inconsistent data, namely it has CCFS1 or CCFS2,
but doesn't advertise support for 160/80+80 bandwidth or "Extended NSS
BW Support", then we cannot use any MCSes in the the higher bandwidth.
Thus, avoid connecting with higher bandwidth since it's less efficient
that way.

Link: https://lore.kernel.org/r/20200528213443.0e55d40c3ccc.I6fd0b4708ebd087e5e46466c3e91f6efbcbef668@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

As HT/VHT elements are not allowed in 6 GHz band, do not include
them in mesh beacon template formation.
Signed-off-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Link: https://lore.kernel.org/r/1589399105-25472-9-git-send-email-rmanohar@codeaurora.org
Link: https://lore.kernel.org/r/20200528193455.76796-2-johannes@sipsolutions.netSigned-off-by: Johannes Berg <johannes.berg@intel.com>

Add 6 GHz operation information (IEEE 802.11ax/D6.0, Figure 9-787k)
while building HE operation element for non-HE AP. This field is used to
determine channel information in the absence of HT/VHT IEs.
Signed-off-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Link: https://lore.kernel.org/r/1589399105-25472-8-git-send-email-rmanohar@codeaurora.org
[fix skb allocation size]
Link: https://lore.kernel.org/r/20200528193455.76796-1-johannes@sipsolutions.netSigned-off-by: Johannes Berg <johannes.berg@intel.com>

Construct HE 6 GHz band capability element (IEEE 802.11ax/D6.0,
9.4.2.261) for association request and mesh beacon. The 6 GHz
capability information is passed by driver through iftypes caps.
Signed-off-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Link: https://lore.kernel.org/r/1589399105-25472-7-git-send-email-rmanohar@codeaurora.org
[handle SMPS, adjust for previous patches, reserve SKB space properly,
 change to handle SKB directly]
Link: https://lore.kernel.org/r/20200528213443.643aa8101111.I3f9747c1147480f65445f13eda5c4a5ed4e86757@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

These capabilities cover what would otherwise be transported
in HT/VHT capabilities, but only a subset thereof that is
actually needed on 6 GHz with HE already present. Expose the
capabilities to userspace, drivers are expected to set them
as using the 6 GHz band (currently) requires HE capability.

Link: https://lore.kernel.org/r/20200528213443.244cd5cb9db8.Icd8c773277a88c837e7e3af1d4d1013cc3b66543@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

Handle 6 GHz band capability element parsing for association.
Signed-off-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Link: https://lore.kernel.org/r/1589399105-25472-4-git-send-email-rmanohar@codeaurora.org
[some renaming to be in line with previous patches]
Link: https://lore.kernel.org/r/20200528213443.a13d7a0b85b0.Ia07584da4fc77aa77c4cc563248d2ce4234ffe5d@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

Handle 6 GHz HE capability while adding new station. It will be used
later in mac80211 station processing.
Signed-off-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Link: https://lore.kernel.org/r/1589399105-25472-2-git-send-email-rmanohar@codeaurora.org
[handle nl80211_set_station, require WME,
 remove NL80211_HE_6GHZ_CAPABILITY_LEN]
Link: https://lore.kernel.org/r/20200528213443.b6b711fd4312.Ic9b97d57b6c4f2b28d4b2d23d2849d8bc20bd8cc@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

Add the HE extended element IDs and the definitions for the
HE 6 GHz band capabilities element, from Draft 5.0.

Link: https://lore.kernel.org/r/20200528213443.1a6689fe093f.Ifdc5400fb01779351354daf38663ebeea03c9ad9@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

Add some code to obtain and parse the 6 GHz operation field
inside the HE operation element.

While at it, fix the required length using sizeof() the new
struct, which is 5 instead of 4 now.

Link: https://lore.kernel.org/r/20200528213443.42ca72c45ca9.Id74bc1b03da9ea6574f9bc70deeb60dfc1634359@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

Add the necessary definitions to parse reduced neighbor
report elements.
Signed-off-by: Tova Mussai <tova.mussai@intel.com>
[change struct name, remove IEEE80211_MIN_AP_NEIGHBOR_INFO_SIZE]
Link: https://lore.kernel.org/r/20200528213443.4f9154461c06.I518d9898ad982f838112ea9ca14a20d6bbb16394@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

This allows identifying whether or not a channel is a PSC
(preferred scanning channel).

Link: https://lore.kernel.org/r/20200528213443.414363ecf62c.Ic15e681a0e249eab7350a06ceb582cca8bb9a080@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

My previous commit here was wrong, it didn't check the new
flag in two necessary places, so things didn't work. Fix that.

Fixes: 155d7c73 ("nl80211: allow client-only BIGTK support")
Link: https://lore.kernel.org/r/20200528213443.993f108e96ca.I0086ae42d672379380d04ac5effb2f3d5135731b@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

The 6GHz band does not have regulatory approval yet, but things are
moving forward. However, that has led to a change in the channelization
of the 6GHz band which has been accepted in the 11ax specification. It
also fixes a missing MHZ_TO_KHZ() macro for 6GHz channels while at it.

This change is primarily thrown in to discuss how to deal with it.
I noticed ath11k adding 6G support with old channelization and ditto
for iw. It probably involves changes in hostapd as well.

Cc: Pradeep Kumar Chitrapu <pradeepc@codeaurora.org>
Cc: Jouni Malinen <jouni@w1.fi>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Link: https://lore.kernel.org/r/edf07cdd-ad15-4012-3afd-d8b961a80b69@broadcom.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

The updates to change to kHz frequencies and the 6 GHz
additions evidently overlapped (or rather, I didn't see
it when applying the latter), so the 6 GHz is broken.
Fix this.

Fixes: 934f4c7d ("cfg80211: express channels with a KHz component")
Link: https://lore.kernel.org/r/20200529140425.1bf824f6911b.I4a1174916b8f5965af4366999eb9ffc7a0347470@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

syzbot was able to trigger a crash after using an ISDN socket
and fool l2tp.

Fix this by making sure the UDP socket is of the proper family.

BUG: KASAN: slab-out-of-bounds in setup_udp_tunnel_sock+0x465/0x540 net/ipv4/udp_tunnel.c:78
Write of size 1 at addr ffff88808ed0c590 by task syz-executor.5/3018

CPU: 0 PID: 3018 Comm: syz-executor.5 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x413 mm/kasan/report.c:382
 __kasan_report.cold+0x20/0x38 mm/kasan/report.c:511
 kasan_report+0x33/0x50 mm/kasan/common.c:625
 setup_udp_tunnel_sock+0x465/0x540 net/ipv4/udp_tunnel.c:78
 l2tp_tunnel_register+0xb15/0xdd0 net/l2tp/l2tp_core.c:1523
 l2tp_nl_cmd_tunnel_create+0x4b2/0xa60 net/l2tp/l2tp_netlink.c:249
 genl_family_rcv_msg_doit net/netlink/genetlink.c:673 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:718 [inline]
 genl_rcv_msg+0x627/0xdf0 net/netlink/genetlink.c:735
 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2469
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:746
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6e6/0x810 net/socket.c:2352
 ___sys_sendmsg+0x100/0x170 net/socket.c:2406
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca29
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007effe76edc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004fe1c0 RCX: 000000000045ca29
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000005
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000094e R14: 00000000004d5d00 R15: 00007effe76ee6d4

Allocated by task 3018:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 __kasan_kmalloc mm/kasan/common.c:495 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x161/0x7a0 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 sk_prot_alloc+0x223/0x2f0 net/core/sock.c:1612
 sk_alloc+0x36/0x1100 net/core/sock.c:1666
 data_sock_create drivers/isdn/mISDN/socket.c:600 [inline]
 mISDN_sock_create+0x272/0x400 drivers/isdn/mISDN/socket.c:796
 __sock_create+0x3cb/0x730 net/socket.c:1428
 sock_create net/socket.c:1479 [inline]
 __sys_socket+0xef/0x200 net/socket.c:1521
 __do_sys_socket net/socket.c:1530 [inline]
 __se_sys_socket net/socket.c:1528 [inline]
 __x64_sys_socket+0x6f/0xb0 net/socket.c:1528
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Freed by task 2484:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 kasan_set_free_info mm/kasan/common.c:317 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x109/0x2b0 mm/slab.c:3757
 kvfree+0x42/0x50 mm/util.c:603
 __free_fdtable+0x2d/0x70 fs/file.c:31
 put_files_struct fs/file.c:420 [inline]
 put_files_struct+0x248/0x2e0 fs/file.c:413
 exit_files+0x7e/0xa0 fs/file.c:445
 do_exit+0xb04/0x2dd0 kernel/exit.c:791
 do_group_exit+0x125/0x340 kernel/exit.c:894
 get_signal+0x47b/0x24e0 kernel/signal.c:2739
 do_signal+0x81/0x2240 arch/x86/kernel/signal.c:784
 exit_to_usermode_loop+0x26c/0x360 arch/x86/entry/common.c:161
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

The buggy address belongs to the object at ffff88808ed0c000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1424 bytes inside of
 2048-byte region [ffff88808ed0c000, ffff88808ed0c800)
The buggy address belongs to the page:
page:ffffea00023b4300 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002838208 ffffea00015ba288 ffff8880aa000e00
raw: 0000000000000000 ffff88808ed0c000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808ed0c480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88808ed0c500: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88808ed0c580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff88808ed0c600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808ed0c680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: 6b9f3423 ("l2tp: fix races in tunnel creation")
Fixes: fd558d18 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Cc: Guillaume Nault <gnault@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>