The verifier allows ARG_PTR_TO_BTF_ID helper arguments to be NULL, so
helper implementations need to check this before dereferencing them.
This was already fixed for the socket storage helpers but not for task
and inode.

The issue can be reproduced by attaching an LSM program to
inode_rename hook (called when moving files) which tries to get the
inode of the new file without checking for its nullness and then trying
to move an existing file to a new path:

  mv existing_file new_file_does_not_exist

The report including the sample program and the steps for reproducing
the bug:

  https://lore.kernel.org/bpf/CANaYP3HWkH91SN=wTNO9FL_2ztHfqcXKX38SSE-JJ2voh+vssw@mail.gmail.com

Fixes: 4cf1bc1f ("bpf: Implement task local storage")
Fixes: 8ea63684 ("bpf: Implement bpf_local_storage for inodes")
Reported-by: Gilad Reti <gilad.reti@gmail.com>
Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210112075525.256820-3-kpsingh@kernel.org

The bpf_tracing_prog_attach error path calls bpf_prog_put
on prog, which causes refcount underflow when it's called
from link_create function.

  link_create
    prog = bpf_prog_get              <-- get
    ...
    tracing_bpf_link_attach(prog..
      bpf_tracing_prog_attach(prog..
        out_put_prog:
          bpf_prog_put(prog);        <-- put

    if (ret < 0)
      bpf_prog_put(prog);            <-- put

Removing bpf_prog_put call from bpf_tracing_prog_attach
and making sure its callers call it instead.

Fixes: 4a1e7c0c ("bpf: Support attaching freplace programs to multiple attach points")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210111191650.1241578-1-jolsa@kernel.org

The merge resolution of the interaction of commits 307eea32
("dt-bindings: net: renesas,ravb: Add support for r8a774e1 SoC") and
d7adf633 ("dt-bindings: net: renesas,etheravb: Convert to
json-schema") missed that "tx-internal-delay-ps" should be a required
property on RZ/G2H.

Fixes: 8b0308fe ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20210105151516.1540653-1-geert+renesas@glider.beSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Ido Schimmel says:

====================
mlxsw: core: Thermal control fixes

This series includes two fixes for thermal control in mlxsw.

Patch #1 validates that the alarm temperature threshold read from a
transceiver is above the warning temperature threshold. If not, the
current thresholds are maintained. It was observed that some transceiver
might be unreliable and sometimes report a too low alarm temperature
threshold which would result in thermal shutdown of the system.

Patch #2 increases the temperature threshold above which thermal
shutdown is triggered for the ASIC thermal zone. It is currently too low
and might result in thermal shutdown under perfectly fine operational
conditions.
====================

Link: https://lore.kernel.org/r/20210108145210.1229820-1-idosch@idosch.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Increase critical threshold for ASIC thermal zone from 110C to 140C
according to the system hardware requirements. All the supported ASICs
(Spectrum-1, Spectrum-2, Spectrum-3) could be still operational with ASIC
temperature below 140C. With the old critical threshold value system
can perform unjustified shutdown.

All the systems equipped with the above ASICs implement thermal
protection mechanism at firmware level and firmware could decide to
perform system thermal shutdown in case the temperature is below 140C.
So with the new threshold system will not meltdown, while thermal
operating range will be aligned with hardware abilities.

Fixes: 41e76084 ("mlxsw: core: Replace thermal temperature trips with defines")
Fixes: a50c1e35 ("mlxsw: core: Implement thermal zone")
Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Validate thresholds to avoid a single failure due to some transceiver
unreliability. Ignore the last readouts in case warning temperature is
above alarm temperature, since it can cause unexpected thermal
shutdown. Stay with the previous values and refresh threshold within
the next iteration.

This is a rare scenario, but it was observed at a customer site.

Fixes: 6a79507c ("mlxsw: core: Extend thermal module with per QSFP module thermal zones")
Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The buffer list can have zero skb as following path:
tipc_named_node_up()->tipc_node_xmit()->tipc_link_xmit(), so
we need to check the list before casting an &sk_buff.

Fault report:
 [] tipc: Bulk publication failure
 [] general protection fault, probably for non-canonical [#1] PREEMPT [...]
 [] KASAN: null-ptr-deref in range [0x00000000000000c8-0x00000000000000cf]
 [] CPU: 0 PID: 0 Comm: swapper/0 Kdump: loaded Not tainted 5.10.0-rc4+ #2
 [] Hardware name: Bochs ..., BIOS Bochs 01/01/2011
 [] RIP: 0010:tipc_link_xmit+0xc1/0x2180
 [] Code: 24 b8 00 00 00 00 4d 39 ec 4c 0f 44 e8 e8 d7 0a 10 f9 48 [...]
 [] RSP: 0018:ffffc90000006ea0 EFLAGS: 00010202
 [] RAX: dffffc0000000000 RBX: ffff8880224da000 RCX: 1ffff11003d3cc0d
 [] RDX: 0000000000000019 RSI: ffffffff886007b9 RDI: 00000000000000c8
 [] RBP: ffffc90000007018 R08: 0000000000000001 R09: fffff52000000ded
 [] R10: 0000000000000003 R11: fffff52000000dec R12: ffffc90000007148
 [] R13: 0000000000000000 R14: 0000000000000000 R15: ffffc90000007018
 [] FS:  0000000000000000(0000) GS:ffff888037400000(0000) knlGS:000[...]
 [] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [] CR2: 00007fffd2db5000 CR3: 000000002b08f000 CR4: 00000000000006f0

Fixes: af9b028e ("tipc: make media xmit call outside node spinlock context")
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Link: https://lore.kernel.org/r/20210108071337.3598-1-hoang.h.le@dektech.com.auSigned-off-by: Jakub Kicinski <kuba@kernel.org>

TLS selftests where broken because of wrong variable types used.
Fix it by changing u16 -> uint16_t

Fixes: 4f336e88 ("selftests/tls: add CHACHA20-POLY1305 to tls selftests")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Link: https://lore.kernel.org/r/1610141865-7142-1-git-send-email-vfedorenko@novek.ruSigned-off-by: Jakub Kicinski <kuba@kernel.org>

There are cases where GSO segment's length exceeds the egress MTU:
 - Forwarding of a TCP GRO skb, when DF flag is not set.
 - Forwarding of an skb that arrived on a virtualisation interface
   (virtio-net/vhost/tap) with TSO/GSO size set by other network
   stack.
 - Local GSO skb transmitted on an NETIF_F_TSO tunnel stacked over an
   interface with a smaller MTU.
 - Arriving GRO skb (or GSO skb in a virtualised environment) that is
   bridged to a NETIF_F_TSO tunnel stacked over an interface with an
   insufficient MTU.

If so:
 - Consume the SKB and its segments.
 - Issue an ICMP packet with 'Packet Too Big' message containing the
   MTU, allowing the source host to reduce its Path MTU appropriately.

Note: These cases are handled in the same manner in IPv4 output finish.
This patch aligns the behavior of IPv6 and the one of IPv4.

Fixes: 9e508490 ("netfilter: ipv6: move POSTROUTING invocation before fragmentation")
Signed-off-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/1610027418-30438-1-git-send-email-ayal@nvidia.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

For all PCI functions on the netxen_nic adapter, interrupt
mode (INTx or MSI) configuration is dependent on what has
been configured by the PCI function zero in the shared
interrupt register, as these adapters do not support mixed
mode interrupts among the functions of a given adapter.

Logic for setting MSI/MSI-x interrupt mode in the shared interrupt
register based on PCI function id zero check is not appropriate for
all family of netxen adapters, as for some of the netxen family
adapters PCI function zero is not really meant to be probed/loaded
in the host but rather just act as a management function on the device,
which caused all the other PCI functions on the adapter to always use
legacy interrupt (INTx) mode instead of choosing MSI/MSI-x interrupt mode.

This patch replaces that check with port number so that for all
type of adapters driver attempts for MSI/MSI-x interrupt modes.

Fixes: b37eb210 ("netxen_nic: Avoid mixed mode interrupts")
Signed-off-by: Manish Chopra <manishc@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Link: https://lore.kernel.org/r/20210107101520.6735-1-manishc@marvell.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Jakub Kicinski says:

====================
net: fix issues around register_netdevice() failures

This series attempts to clean up the life cycle of struct
net_device. Dave has added dev->needs_free_netdev in the
past to fix double frees, we can lean on that mechanism
a little more to fix remaining issues with register_netdevice().

This is the next chapter of the saga which already includes:
commit 0e0eee24 ("net: correct error path in rtnl_newlink()")
commit e51fb152 ("rtnetlink: fix a memory leak when ->newlink fails")
commit cf124db5 ("net: Fix inconsistent teardown and release of private netdev state.")
commit 93ee31f1 ("[NET]: Fix free_netdev on register_netdev failure.")
commit 814152a8 ("net: fix memleak in register_netdevice()")
commit 10cc514f ("net: Fix null de-reference of device refcount")

The immediate problem which gets fixed here is that calling
free_netdev() right after unregister_netdevice() is illegal
because we need to release rtnl_lock first, to let the
unregistration finish. Note that unregister_netdevice() is
just a wrapper of unregister_netdevice_queue(), it only
does half of the job.

Where this limitation becomes most problematic is in failure
modes of register_netdevice(). There is a notifier call right
at the end of it, which lets other subsystems veto the entire
thing. At which point we should really go through a full
unregister_netdevice(), but we can't because callers may
go straight to free_netdev() after the failure, and that's
no bueno (see the previous paragraph).

This set makes free_netdev() more lenient, when device
is still being unregistered free_netdev() will simply set
dev->needs_free_netdev and let the unregister process do
the freeing.

With the free_netdev() problem out of the way failures in
register_netdevice() can make use of net_todo, again.
Users are still expected to call free_netdev() right after
failure but that will only set dev->needs_free_netdev.

To prevent the pathological case of:

 dev->needs_free_netdev = true;
 if (register_netdevice(dev)) {
   rtnl_unlock();
   free_netdev(dev);
 }

make register_netdevice()'s failure clear dev->needs_free_netdev.

Problems described above are only present with register_netdevice() /
unregister_netdevice(). We have two parallel APIs for registration
of devices:
 - those called outside rtnl_lock (register_netdev(), and
   unregister_netdev());
 - and those to be used under rtnl_lock - register_netdevice()
   and unregister_netdevice().
The former is trivial and has no problems. The alternative
approach to fix the latter would be to also separate the
freeing functions - i.e. add free_netdevice(). This has been
implemented (incl. converting all relevant calls in the tree)
but it feels a little unnecessary to put the burden of choosing
the right free_netdev{,ice}() call on the programmer when we
can "just do the right thing" by default.
====================

Link: https://lore.kernel.org/r/20210106184007.1821480-1-kuba@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

If register_netdevice() fails at the very last stage - the
notifier call - some subsystems may have already seen it and
grabbed a reference. struct net_device can't be freed right
away without calling netdev_wait_all_refs().

Now that we have a clean interface in form of dev->needs_free_netdev
and lenient free_netdev() we can undo what commit 93ee31f1 ("[NET]:
Fix free_netdev on register_netdev failure.") has done and complete
the unregistration path by bringing the net_set_todo() call back.

After registration fails user is still expected to explicitly
free the net_device, so make sure ->needs_free_netdev is cleared,
otherwise rolling back the registration will cause the old double
free for callers who release rtnl_lock before the free.

This also solves the problem of priv_destructor not being called
on notifier error.

net_set_todo() will be moved back into unregister_netdevice_queue()
in a follow up.
Reported-by: Hulk Robot <hulkci@huawei.com>
Reported-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

There are two flavors of handling netdev registration:
 - ones called without holding rtnl_lock: register_netdev() and
   unregister_netdev(); and
 - those called with rtnl_lock held: register_netdevice() and
   unregister_netdevice().

While the semantics of the former are pretty clear, the same can't
be said about the latter. The netdev_todo mechanism is utilized to
perform some of the device unregistering tasks and it hooks into
rtnl_unlock() so the locked variants can't actually finish the work.
In general free_netdev() does not mix well with locked calls. Most
drivers operating under rtnl_lock set dev->needs_free_netdev to true
and expect core to make the free_netdev() call some time later.

The part where this becomes most problematic is error paths. There is
no way to unwind the state cleanly after a call to register_netdevice(),
since unreg can't be performed fully without dropping locks.

Make free_netdev() more lenient, and defer the freeing if device
is being unregistered. This allows error paths to simply call
free_netdev() both after register_netdevice() failed, and after
a call to unregister_netdevice() but before dropping rtnl_lock.

Simplify the error paths which are currently doing gymnastics
around free_netdev() handling.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Explain the two basic flows of struct net_device's operation.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When setting up a channel bridge, ppp_bridge_channels sets the
pch->bridge field before taking the associated reference on the bridge
file instance.

This opens up a refcount underflow bug if ppp_bridge_channels called
via. iotcl runs concurrently with ppp_unbridge_channels executing via.
file release.

The bug is triggered by ppp_bridge_channels taking the error path
through the 'err_unset' label.  In this scenario, pch->bridge is set,
but the reference on the bridged channel will not be taken because
the function errors out.  If ppp_unbridge_channels observes pch->bridge
before it is unset by the error path, it will erroneously drop the
reference on the bridged channel and cause a refcount underflow.

To avoid this, ensure that ppp_bridge_channels holds a reference on
each channel in advance of setting the bridge pointers.
Signed-off-by: Tom Parkin <tparkin@katalix.com>
Fixes: 4cf476ce ("ppp: add PPPIOCBRIDGECHAN and PPPIOCUNBRIDGECHAN ioctls")
Acked-by: Guillaume Nault <gnault@redhat.com>
Link: https://lore.kernel.org/r/20210107181315.3128-1-tparkin@katalix.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

reuse->socks[] is modified concurrently by reuseport_add_sock. To
prevent reading values that have not been fully initialized, only read
the array up until the last known safe index instead of incorrectly
re-reading the last index of the array.

Fixes: acdcecc6 ("udp: correct reuseport selection with connected sockets")
Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20210107051110.12247-1-baptiste.lepers@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

skbs in fraglist could be shared by a BPF filter loaded at TC. If TC
writes, it will call skb_ensure_writable -> pskb_expand_head to create
a private linear section for the head_skb. And then call
skb_clone_fraglist -> skb_get on each skb in the fraglist.

skb_segment_list overwrites part of the skb linear section of each
fragment itself. Even after skb_clone, the frag_skbs share their
linear section with their clone in PF_PACKET.

Both sk_receive_queue of PF_PACKET and PF_INET (or PF_INET6) can have
a link for the same frag_skbs chain. If a new skb (not frags) is
queued to one of the sk_receive_queue, multiple ptypes can see and
release this. It causes use-after-free.

[ 4443.426215] ------------[ cut here ]------------
[ 4443.426222] refcount_t: underflow; use-after-free.
[ 4443.426291] WARNING: CPU: 7 PID: 28161 at lib/refcount.c:190
refcount_dec_and_test_checked+0xa4/0xc8
[ 4443.426726] pstate: 60400005 (nZCv daif +PAN -UAO)
[ 4443.426732] pc : refcount_dec_and_test_checked+0xa4/0xc8
[ 4443.426737] lr : refcount_dec_and_test_checked+0xa0/0xc8
[ 4443.426808] Call trace:
[ 4443.426813]  refcount_dec_and_test_checked+0xa4/0xc8
[ 4443.426823]  skb_release_data+0x144/0x264
[ 4443.426828]  kfree_skb+0x58/0xc4
[ 4443.426832]  skb_queue_purge+0x64/0x9c
[ 4443.426844]  packet_set_ring+0x5f0/0x820
[ 4443.426849]  packet_setsockopt+0x5a4/0xcd0
[ 4443.426853]  __sys_setsockopt+0x188/0x278
[ 4443.426858]  __arm64_sys_setsockopt+0x28/0x38
[ 4443.426869]  el0_svc_common+0xf0/0x1d0
[ 4443.426873]  el0_svc_handler+0x74/0x98
[ 4443.426880]  el0_svc+0x8/0xc

Fixes: 3a1296a3 (net: Support GRO/GSO fraglist chaining.)
Signed-off-by: Dongseok Yi <dseok.yi@samsung.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/1610072918-174177-1-git-send-email-dseok.yi@samsung.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

At the moment it is quite hard to identify the network interface
provided by IPA in userspace components: The network interface is
created as virtual device, without any link to the IPA device.
The interface name ("rmnet_ipa%d") is the only indication that the
network interface belongs to IPA, but this is not very reliable.

Add SET_NETDEV_DEV() to associate the network interface with the
IPA parent device. This allows userspace services like ModemManager
to properly identify that this network interface is provided by IPA
and belongs to the modem.

Cc: Alex Elder <elder@kernel.org>
Fixes: a646d6ec ("soc: qcom: ipa: modem and microcontroller")
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20210106100755.56800-1-stephan@gerhold.netSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Pull more networking fixes from Jakub Kicinski:
 "Slightly lighter pull request to get back into the Thursday cadence.

  Current release - always broken:

   - can: mcp251xfd: fix Tx/Rx ring buffer driver race conditions

   - dsa: hellcreek: fix led_classdev build errors

  Previous releases - regressions:

   - ipv6: fib: flush exceptions when purging route to avoid netdev
     reference leak

   - ip_tunnels: fix pmtu check in nopmtudisc mode

   - ip: always refragment ip defragmented packets to avoid MTU issues
     when forwarding through tunnels, correct "packet too big" message
     is prohibitively tricky to generate

   - s390/qeth: fix locking for discipline setup / removal and during
     recovery to prevent both deadlocks and races

   - mlx5: Use port_num 1 instead of 0 when delete a RoCE address

  Previous releases - always broken:

   - cdc_ncm: correct overhead calculation in delayed_ndp_size to
     prevent out of bound accesses with Huawei 909s-120 LTE module

   - fix stmmac dwmac-sun8i suspend/resume:
           - PHY being left powered off
           - MAC syscon configuration being reset
           - reference to the reset controller being improperly dropped

   - qrtr: fix null-ptr-deref in qrtr_ns_remove

   - can: tcan4x5x: fix bittiming const, use common bittiming from m_can
     driver

   - mlx5e: CT: Use per flow counter when CT flow accounting is enabled

   - mlx5e: Fix SWP offsets when vlan inserted by driver

  Misc:

   - bpf: Fix a task_iter bug caused by a bpf -> net merge conflict
     resolution

  And the usual many fixes to various error paths"

* tag 'net-5.11-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (69 commits)
  net: dsa: lantiq_gswip: Exclude RMII from modes that report 1 GbE
  s390/qeth: fix L2 header access in qeth_l3_osa_features_check()
  s390/qeth: fix locking for discipline setup / removal
  s390/qeth: fix deadlock during recovery
  selftests: fib_nexthops: Fix wrong mausezahn invocation
  nexthop: Bounce NHA_GATEWAY in FDB nexthop groups
  nexthop: Unlink nexthop group entry in error path
  nexthop: Fix off-by-one error in error path
  octeontx2-af: fix memory leak of lmac and lmac->name
  chtls: Fix chtls resources release sequence
  chtls: Added a check to avoid NULL pointer dereference
  chtls: Replace skb_dequeue with skb_peek
  chtls: Avoid unnecessary freeing of oreq pointer
  chtls: Fix panic when route to peer not configured
  chtls: Remove invalid set_tcb call
  chtls: Fix hardware tid leak
  net: ip: always refragment ip defragmented packets
  net: fix pmtu check in nopmtudisc mode
  selftests: netfilter: add selftest for ipip pmtu discovery with enabled connection tracking
  docs: octeontx2: tune rst markup
  ...

Pull crypto fixes from Herbert Xu:
 "This fixes a functional bug in arm/chacha-neon as well as a potential
  buffer overflow in ecdh"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: ecdh - avoid buffer overflow in ecdh_set_secret()
  crypto: arm/chacha-neon - add missing counter increment

The kernel test robot reported a -5.8% performance regression on the
"poll2" test of will-it-scale, and bisected it to commit d55564cf
("x86: Make __put_user() generate an out-of-line call").

I didn't expect an out-of-line __put_user() to matter, because no normal
core code should use that non-checking legacy version of user access any
more.  But I had overlooked the very odd poll() usage, which does a
__put_user() to update the 'revents' values of the poll array.

Now, Al Viro correctly points out that instead of updating just the
'revents' field, it would be much simpler to just copy the _whole_
pollfd entry, and then we could just use "copy_to_user()" on the whole
array of entries, the same way we use "copy_from_user()" a few lines
earlier to get the original values.

But that is not what we've traditionally done, and I worry that threaded
applications might be concurrently modifying the other fields of the
pollfd array.  So while Al's suggestion is simpler - and perhaps worth
trying in the future - this instead keeps the "just update revents"
model.

To fix the performance regression, use the modern "unsafe_put_user()"
instead of __put_user(), with the proper "user_write_access_begin()"
guarding in place. This improves code generation enormously.

Link: https://lore.kernel.org/lkml/20210107134723.GA28532@xsang-OptiPlex-9020/Reported-by: kernel test robot <oliver.sang@intel.com>
Tested-by: Oliver Sang <oliver.sang@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Laight <David.Laight@aculab.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit 757055ae.

The commit caused that ttynull was used as the default console
on several systems[1][2][3]. As a result, the console was
blank even when a better alternative existed.

It happened when there was no console configured
on the command line and ttynull_init() was the first initcall
calling register_console().

Or it happened when /dev/ did not exist when console_on_rootfs()
was called. It was not able to open /dev/console even though
a console driver was registered. It tried to add ttynull console
but it obviously did not help. But ttynull became the preferred
console and was used by /dev/console when it was available later.

The commit tried to fix a historical problem that have been there
for ages. The primary motivation was the commit 3cffa06a
("printk/console: Allow to disable console output by using console=""
 or console=null"). It provided a clean solution for a workaround
 that was widely used and worked only by chance.

This revert causes that the console="" or console=null command line
options will again work only by chance. These options will cause that
a particular console will be preferred and the default (tty) ones
will not get enabled. There will be no console registered at
all. As a result there won't be stdin, stdout, and stderr for
the init process. But it worked exactly this way even before.

The proper solution has to fulfill many conditions:

  + Register ttynull only when explicitly required or as
    the ultimate fallback.

  + ttynull should get associated with /dev/console but it must
    not become preferred console when used as a fallback.
    Especially, it must still be possible to replace it
    by a better console later.

Such a change requires clean up of the register_console() code.
Otherwise, it would be even harder to follow. Especially, the use
of has_preferred_console and CON_CONSDEV flag is tricky. The clean
up is risky. The ordering of consoles is not well defined. And
any changes tend to break existing user settings.

Do the revert at the least risky solution for now.

[1] https://lore.kernel.org/linux-kselftest/20201221144302.GR4077@smile.fi.intel.com/
[2] https://lore.kernel.org/lkml/d2a3b3c0-e548-7dd1-730f-59bc5c04e191@synopsys.com/
[3] https://patchwork.ozlabs.org/project/linux-um/patch/20210105120128.10854-1-thomas@m3y3r.de/Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reported-by: Vineet Gupta <vgupta@synopsys.com>
Reported-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Saeed Mahameed says:

====================
mlx5 fixes 2021-01-07

* tag 'mlx5-fixes-2021-01-07' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux:
  net/mlx5e: Fix memleak in mlx5e_create_l2_table_groups
  net/mlx5e: Fix two double free cases
  net/mlx5: Release devlink object if adev fails
  net/mlx5e: ethtool, Fix restriction of autoneg with 56G
  net/mlx5e: In skb build skip setting mark in switchdev mode
  net/mlx5: E-Switch, fix changing vf VLANID
  net/mlx5e: Fix SWP offsets when vlan inserted by driver
  net/mlx5e: CT: Use per flow counter when CT flow accounting is enabled
  net/mlx5: Use port_num 1 instead of 0 when delete a RoCE address
  net/mlx5e: Add missing capability check for uplink follow
  net/mlx5: Check if lag is supported before creating one
====================

Link: https://lore.kernel.org/r/20210107202845.470205-1-saeed@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Exclude RMII from modes that report 1 GbE support. Reduced MII supports
up to 100 MbE.

Fixes: 14fceff4 ("net: dsa: Add Lantiq / Intel DSA driver for vrx200")
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210107195818.3878-1-olek2@wp.plSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Julian Wiedmann says:

====================
s390/qeth: fixes 2021-01-07

This brings two locking fixes for the device control path.
Also one fix for a path where our .ndo_features_check() attempts to
access a non-existent L2 header.
====================

Link: https://lore.kernel.org/r/20210107172442.1737-1-jwi@linux.ibm.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

ip_finish_output_gso() may call .ndo_features_check() even before the
skb has a L2 header. This conflicts with qeth_get_ip_version()'s attempt
to inspect the L2 header via vlan_eth_hdr().

Switch to vlan_get_protocol(), as already used further down in the
common qeth_features_check() path.

Fixes: f13ade19 ("s390/qeth: run non-offload L3 traffic over common xmit path")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Due to insufficient locking, qeth_core_set_online() and
qeth_dev_layer2_store() can run in parallel, both attempting to load &
setup the discipline (and stepping on each other toes along the way).
A similar race can also occur between qeth_core_remove_device() and
qeth_dev_layer2_store().

Access to .discipline is meant to be protected by the discipline_mutex,
so add/expand the locking in qeth_core_remove_device() and
qeth_core_set_online().
Adjust the locking in qeth_l*_remove_device() accordingly, as it's now
handled by the callers in a consistent manner.

Based on an initial patch by Ursula Braun.

Fixes: 9dc48ccc ("qeth: serialize sysfs-triggered device configurations")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When qeth_dev_layer2_store() - holding the discipline_mutex - waits
inside qeth_l*_remove_device() for a qeth_do_reset() thread to complete,
we can hit a deadlock if qeth_do_reset() concurrently calls
qeth_set_online() and thus tries to aquire the discipline_mutex.

Move the discipline_mutex locking outside of qeth_set_online() and
qeth_set_offline(), and turn the discipline into a parameter so that
callers understand the dependency.

To fix the deadlock, we can now relax the locking:
As already established, qeth_l*_remove_device() waits for
qeth_do_reset() to complete. So qeth_do_reset() itself is under no risk
of having card->discipline ripped out while it's running, and thus
doesn't need to take the discipline_mutex.

Fixes: 9dc48ccc ("qeth: serialize sysfs-triggered device configurations")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Ido Schimmel says:

====================
nexthop: Various fixes

This series contains various fixes for the nexthop code. The bugs were
uncovered during the development of resilient nexthop groups.

Patches #1-#2 fix the error path of nexthop_create_group(). I was not
able to trigger these bugs with current code, but it is possible with
the upcoming resilient nexthop groups code which adds a user
controllable memory allocation further in the function.

Patch #3 fixes wrong validation of netlink attributes.

Patch #4 fixes wrong invocation of mausezahn in a selftest.
====================

Link: https://lore.kernel.org/r/20210107144824.1135691-1-idosch@idosch.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

For IPv6 traffic, mausezahn needs to be invoked with '-6'. Otherwise an
error is returned:

 # ip netns exec me mausezahn veth1 -B 2001:db8:101::2 -A 2001:db8:91::1 -c 0 -t tcp "dp=1-1023, flags=syn"
 Failed to set source IPv4 address. Please check if source is set to a valid IPv4 address.
  Invalid command line parameters!

Fixes: 7c741868 ("selftests: Add torture tests to nexthop tests")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The function nh_check_attr_group() is called to validate nexthop groups.
The intention of that code seems to have been to bounce all attributes
above NHA_GROUP_TYPE except for NHA_FDB. However instead it bounces all
these attributes except when NHA_FDB attribute is present--then it accepts
them.

NHA_FDB validation that takes place before, in rtm_to_nh_config(), already
bounces NHA_OIF, NHA_BLACKHOLE, NHA_ENCAP and NHA_ENCAP_TYPE. Yet further
back, NHA_GROUPS and NHA_MASTER are bounced unconditionally.

But that still leaves NHA_GATEWAY as an attribute that would be accepted in
FDB nexthop groups (with no meaning), so long as it keeps the address
family as unspecified:

 # ip nexthop add id 1 fdb via 127.0.0.1
 # ip nexthop add id 10 fdb via default group 1

The nexthop code is still relatively new and likely not used very broadly,
and the FDB bits are newer still. Even though there is a reproducer out
there, it relies on an improbable gateway arguments "via default", "via
all" or "via any". Given all this, I believe it is OK to reformulate the
condition to do the right thing and bounce NHA_GATEWAY.

Fixes: 38428d68 ("nexthop: support for fdb ecmp nexthops")
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In case of error, remove the nexthop group entry from the list to which
it was previously added.

Fixes: 430a0491 ("nexthop: Add support for nexthop groups")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

A reference was not taken for the current nexthop entry, so do not try
to put it in the error path.

Fixes: 430a0491 ("nexthop: Add support for nexthop groups")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Currently the error return paths don't kfree lmac and lmac->name
leading to some memory leaks.  Fix this by adding two error return
paths that kfree these objects

Addresses-Coverity: ("Resource leak")
Fixes: 1463f382 ("octeontx2-af: Add support for CGX link management")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210107123916.189748-1-colin.king@canonical.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Ayush Sawal says:

====================
Bug fixes for chtls driver

patch 1: Fix hardware tid leak.
patch 2: Remove invalid set_tcb call.
patch 3: Fix panic when route to peer not configured.
patch 4: Avoid unnecessary freeing of oreq pointer.
patch 5: Replace skb_dequeue with skb_peek.
patch 6: Added a check to avoid NULL pointer dereference patch.
patch 7: Fix chtls resources release sequence.
====================

Link: https://lore.kernel.org/r/20210106042912.23512-1-ayush.sawal@chelsio.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

CPL_ABORT_RPL is sent after releasing the resources by calling
chtls_release_resources(sk); and chtls_conn_done(sk);
eventually causing kernel panic. Fixing it by calling release
in appropriate order.

Fixes: cc35c88a ("crypto : chtls - CPL handler definition")
Signed-off-by: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
Signed-off-by: Ayush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In case of server removal lookup_stid() may return NULL pointer, which
is used as listen_ctx. So added a check before accessing this pointer.

Fixes: cc35c88a ("crypto : chtls - CPL handler definition")
Signed-off-by: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
Signed-off-by: Ayush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The skb is unlinked twice, one in __skb_dequeue in function
chtls_reset_synq() and another in cleanup_syn_rcv_conn().
So in this patch using skb_peek() instead of __skb_dequeue(),
so that unlink will be handled only in cleanup_syn_rcv_conn().

Fixes: cc35c88a ("crypto : chtls - CPL handler definition")
Signed-off-by: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
Signed-off-by: Ayush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In chtls_pass_accept_request(), removing the chtls_reqsk_free()
call to avoid oreq freeing twice. Here oreq is the pointer to
struct request_sock.

Fixes: cc35c88a ("crypto : chtls - CPL handler definition")
Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Signed-off-by: Ayush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

If route to peer is not configured, we might get non tls
devices from dst_neigh_lookup() which is invalid, adding a
check to avoid it.

Fixes: cc35c88a ("crypto : chtls - CPL handler definition")
Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Signed-off-by: Ayush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>