rose_send_frame() dereferences `neigh->dev` when called from
rose_transmit_clear_request(), and the first occurrence of the
`neigh` is in rose_loopback_timer() as `rose_loopback_neigh`,
and it is initialized in rose_add_loopback_neigh() as NULL.
i.e when `rose_loopback_neigh` used in rose_loopback_timer()
its `->dev` was still NULL and rose_loopback_timer() was calling
rose_rx_call_request() without checking for NULL.

- net/rose/rose_link.c
This bug seems to get triggered in this line:

rose_call = (ax25_address *)neigh->dev->dev_addr;

Fix it by adding NULL checking for `rose_loopback_neigh->dev`
in rose_loopback_timer().

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Reported-by: syzbot+a1c743815982d9496393@syzkaller.appspotmail.com
Tested-by: syzbot+a1c743815982d9496393@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=9d2a7ca8c7f2e4b682c97578dfa3f236258300b3Signed-off-by: Anmol Karn <anmol.karan123@gmail.com>
Link: https://lore.kernel.org/r/20201119191043.28813-1-anmol.karan123@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Email from solarflare.com will stop working. Update the maintainers.
A replacement for linux-net-drivers@solarflare.com is not working yet,
for now remove it.
Signed-off-by: Martin Habets <mhabets@solarflare.com>
Signed-off-by: Edward Cree <ecree@solarflare.com>
Link: https://lore.kernel.org/r/20201120113207.GA1605547@mh-desktopSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: c0c050c5 ("bnxt_en: New Broadcom ethernet driver.")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Link: https://lore.kernel.org/r/1605792621-6268-1-git-send-email-zhangchangzhong@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: c213eae8 ("bnxt_en: Improve VF/PF link change logic.")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Link: https://lore.kernel.org/r/1605701851-20270-1-git-send-email-zhangchangzhong@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.10-rc5, including fixes from the WiFi
  (mac80211), can and bpf (including the strncpy_from_user fix).

  Current release - regressions:

   - mac80211: fix memory leak of filtered powersave frames

   - mac80211: free sta in sta_info_insert_finish() on errors to avoid
     sleeping in atomic context

   - netlabel: fix an uninitialized variable warning added in -rc4

  Previous release - regressions:

   - vsock: forward all packets to the host when no H2G is registered,
     un-breaking AWS Nitro Enclaves

   - net: Exempt multicast addresses from five-second neighbor lifetime
     requirement, decreasing the chances neighbor tables fill up

   - net/tls: fix corrupted data in recvmsg

   - qed: fix ILT configuration of SRC block

   - can: m_can: process interrupt only when not runtime suspended

  Previous release - always broken:

   - page_frag: Recover from memory pressure by not recycling pages
     allocating from the reserves

   - strncpy_from_user: Mask out bytes after NUL terminator

   - ip_tunnels: Set tunnel option flag only when tunnel metadata is
     present, always setting it confuses Open vSwitch

   - bpf, sockmap:
      - Fix partial copy_page_to_iter so progress can still be made
      - Fix socket memory accounting and obeying SO_RCVBUF

   - net: Have netpoll bring-up DSA management interface

   - net: bridge: add missing counters to ndo_get_stats64 callback

   - tcp: brr: only postpone PROBE_RTT if RTT is < current min_rtt

   - enetc: Workaround MDIO register access HW bug

   - net/ncsi: move netlink family registration to a subsystem init,
     instead of tying it to driver probe

   - net: ftgmac100: unregister NC-SI when removing driver to avoid
     crash

   - lan743x:
      - prevent interrupt storm on open
      - fix freeing skbs in the wrong context

   - net/mlx5e: Fix socket refcount leak on kTLS RX resync

   - net: dsa: mv88e6xxx: Avoid VLAN database corruption on 6097

   - fix 21 unset return codes and other mistakes on error paths, mostly
     detected by the Hulk Robot"

* tag 'net-5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (115 commits)
  fail_function: Remove a redundant mutex unlock
  selftest/bpf: Test bpf_probe_read_user_str() strips trailing bytes after NUL
  lib/strncpy_from_user.c: Mask out bytes after NUL terminator.
  net/smc: fix direct access to ib_gid_addr->ndev in smc_ib_determine_gid()
  net/smc: fix matching of existing link groups
  ipv6: Remove dependency of ipv6_frag_thdr_truncated on ipv6 module
  libbpf: Fix VERSIONED_SYM_COUNT number parsing
  net/mlx4_core: Fix init_hca fields offset
  atm: nicstar: Unmap DMA on send error
  page_frag: Recover from memory pressure
  net: dsa: mv88e6xxx: Wait for EEPROM done after HW reset
  mlxsw: core: Use variable timeout for EMAD retries
  mlxsw: Fix firmware flashing
  net: Have netpoll bring-up DSA management interface
  atl1e: fix error return code in atl1e_probe()
  atl1c: fix error return code in atl1c_probe()
  ah6: fix error return code in ah6_input()
  net: usb: qmi_wwan: Set DTR quirk for MR400
  can: m_can: process interrupt only when not runtime suspended
  can: flexcan: flexcan_chip_start(): fix erroneous flexcan_transceiver_enable() during bus-off recovery
  ...

Pull rdma fixes from Jason Gunthorpe:
 "The last two weeks have been quiet here, just the usual smattering of
  long standing bug fixes.

  A collection of error case bug fixes:

   - Improper nesting of spinlock types in cm

   - Missing error codes and kfree()

   - Ensure dma_virt_ops users have the right kconfig symbols to work
     properly

   - Compilation failure of tools/testing"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  tools/testing/scatterlist: Fix test to compile and run
  IB/hfi1: Fix error return code in hfi1_init_dd()
  RMDA/sw: Don't allow drivers using dma_virt_ops on highmem configs
  RDMA/pvrdma: Fix missing kfree() in pvrdma_register_device()
  RDMA/cm: Make the local_id_table xarray non-irq

Alexei Starovoitov says:

====================
1) libbpf should not attempt to load unused subprogs, from Andrii.

2) Make strncpy_from_user() mask out bytes after NUL terminator, from Daniel.

3) Relax return code check for subprograms in the BPF verifier, from Dmitrii.

4) Fix several sockmap issues, from John.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  fail_function: Remove a redundant mutex unlock
  selftest/bpf: Test bpf_probe_read_user_str() strips trailing bytes after NUL
  lib/strncpy_from_user.c: Mask out bytes after NUL terminator.
  libbpf: Fix VERSIONED_SYM_COUNT number parsing
  bpf, sockmap: Avoid failures from skb_to_sgvec when skb has frag_list
  bpf, sockmap: Handle memory acct if skb_verdict prog redirects to self
  bpf, sockmap: Avoid returning unneeded EAGAIN when redirecting to self
  bpf, sockmap: Use truesize with sk_rmem_schedule()
  bpf, sockmap: Ensure SO_RCVBUF memory is observed on ingress redirect
  bpf, sockmap: Fix partial copy_page_to_iter so progress can still be made
  selftests/bpf: Fix error return code in run_getsockopt_test()
  bpf: Relax return code check for subprograms
  tools, bpftool: Add missing close before bpftool net attach exit
  MAINTAINERS/bpf: Update Andrii's entry.
  selftests/bpf: Fix unused attribute usage in subprogs_unused test
  bpf: Fix unsigned 'datasec_id' compared with zero in check_pseudo_btf_id
  bpf: Fix passing zero to PTR_ERR() in bpf_btf_printf_prepare
  libbpf: Don't attempt to load unused subprog as an entry-point BPF program
====================

Link: https://lore.kernel.org/r/20201119200721.288-1-alexei.starovoitov@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Fix a mutex_unlock() issue where before copy_from_user() is
not called mutex_locked.

Fixes: 4b1a29a7 ("error-injection: Support fault injection framework")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Luo Meng <luomeng12@huawei.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/bpf/160570737118.263807.8358435412898356284.stgit@devnote2

Daniel Xu says:

====================

6ae08ae3 ("bpf: Add probe_read_{user, kernel} and probe_read_{user,
kernel}_str helpers") introduced a subtle bug where
bpf_probe_read_user_str() would potentially copy a few extra bytes after
the NUL terminator.

This issue is particularly nefarious when strings are used as map keys,
as seemingly identical strings can occupy multiple entries in a map.

This patchset fixes the issue and introduces a selftest to prevent
future regressions.

v6 -> v7:
* Add comments

v5 -> v6:
* zero-pad up to sizeof(unsigned long) after NUL

v4 -> v5:
* don't read potentially uninitialized memory

v3 -> v4:
* directly pass userspace pointer to prog
* test more strings of different length

v2 -> v3:
* set pid filter before attaching prog in selftest
* use long instead of int as bpf_probe_read_user_str() retval
* style changes

v1 -> v2:
* add Fixes: tag
* add selftest
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Previously, bpf_probe_read_user_str() could potentially overcopy the
trailing bytes after the NUL due to how do_strncpy_from_user() does the
copy in long-sized strides. The issue has been fixed in the previous
commit.

This commit adds a selftest that ensures we don't regress
bpf_probe_read_user_str() again.
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/4d977508fab4ec5b7b574b85bdf8b398868b6ee9.1605642949.git.dxu@dxuuu.xyz

do_strncpy_from_user() may copy some extra bytes after the NUL
terminator into the destination buffer. This usually does not matter for
normal string operations. However, when BPF programs key BPF maps with
strings, this matters a lot.

A BPF program may read strings from user memory by calling the
bpf_probe_read_user_str() helper which eventually calls
do_strncpy_from_user(). The program can then key a map with the
destination buffer. BPF map keys are fixed-width and string-agnostic,
meaning that map keys are treated as a set of bytes.

The issue is when do_strncpy_from_user() overcopies bytes after the NUL
terminator, it can result in seemingly identical strings occupying
multiple slots in a BPF map. This behavior is subtle and totally
unexpected by the user.

This commit masks out the bytes following the NUL while preserving
long-sized stride in the fast path.

Fixes: 6ae08ae3 ("bpf: Add probe_read_{user, kernel} and probe_read_{user, kernel}_str helpers")
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/21efc982b3e9f2f7b0379eed642294caaa0c27a7.1605642949.git.dxu@dxuuu.xyz

Pull powerpc fixes from Michael Ellerman:
 "Fixes for CVE-2020-4788.

  From Daniel's cover letter:

  IBM Power9 processors can speculatively operate on data in the L1
  cache before it has been completely validated, via a way-prediction
  mechanism. It is not possible for an attacker to determine the
  contents of impermissible memory using this method, since these
  systems implement a combination of hardware and software security
  measures to prevent scenarios where protected data could be leaked.

  However these measures don't address the scenario where an attacker
  induces the operating system to speculatively execute instructions
  using data that the attacker controls. This can be used for example to
  speculatively bypass "kernel user access prevention" techniques, as
  discovered by Anthony Steinhauser of Google's Safeside Project. This
  is not an attack by itself, but there is a possibility it could be
  used in conjunction with side-channels or other weaknesses in the
  privileged code to construct an attack.

  This issue can be mitigated by flushing the L1 cache between privilege
  boundaries of concern.

  This patch series flushes the L1 cache on kernel entry (patch 2) and
  after the kernel performs any user accesses (patch 3). It also adds a
  self-test and performs some related cleanups"

* tag 'powerpc-cve-2020-4788' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: rename pnv|pseries_setup_rfi_flush to _setup_security_mitigations
  selftests/powerpc: refactor entry and rfi_flush tests
  selftests/powerpc: entry flush test
  powerpc: Only include kup-radix.h for 64-bit Book3S
  powerpc/64s: flush L1D after user accesses
  powerpc/64s: flush L1D on kernel entry
  selftests/powerpc: rfi_flush: disable entry flush if present

Pull xtensa fixes from Max Filippov:

 - fix placement of cache alias remapping area

 - disable preemption around cache alias management calls

 - add missing __user annotation to strncpy_from_user argument

* tag 'xtensa-20201119' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: uaccess: Add missing __user to strncpy_from_user() prototype
  xtensa: disable preemption around cache alias management calls
  xtensa: fix TLBTEMP area placement

Pull ACPI fixes from Rafael Wysocki:
 "These fix recent regression in the APEI code and initialization issue
  in the ACPI fan driver.

  Specifics:

   - Make the APEI code avoid attempts to obtain logical addresses for
     registers located in the I/O address space to fix initialization
     issues (Aili Yao)

   - Fix sysfs attribute initialization in the ACPI fan driver (Guenter
     Roeck)"

* tag 'acpi-5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI, APEI, Fix error return value in apei_map_generic_address()
  ACPI: fan: Initialize performance state sysfs attribute

Pull power management fixes from Rafael Wysocki:
 "These fix two issues in ARM cpufreq drivers and one cpuidle driver
  issue.

  Specifics:

   - Add missing RCU_NONIDLE() annotations to the Tegra cpuidle driver
     (Dmitry Osipenko)

   - Fix boot frequency computation in the tegra186 cpufreq driver (Jon
     Hunter)

   - Make the SCMI cpufreq driver register a dummy clock provider to
     avoid OPP addition failures (Sudeep Holla)"

* tag 'pm-5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: scmi: Fix OPP addition failure with a dummy clock provider
  cpufreq: tegra186: Fix get frequency callback
  cpuidle: tegra: Annotate tegra_pm_set_cpu_in_lp2() with RCU_NONIDLE

Pull spi fixes from Mark Brown:
 "This is a relatively large set of fixes, the bulk of it being a series
  from Lukas Wunner which fixes confusion with the lifetime of driver
  data allocated along with the SPI controller structure that's been
  created as part of the conversion to devm APIs.

  The simplest fix, explained in detail in Lukas' commit message, is to
  move to a devm_ function for allocation of the controller and hence
  driver data in order to push the free of that after anything tries to
  reference the driver data in the remove path. This results in a
  relatively large diff due to the addition of a new function but isn't
  particularly complex.

  There's also a fix from Sven van Asbroeck which fixes yet more fallout
  from the conflicts between the various different places one can
  configure the polarity of GPIOs in modern systems.

  Otherwise everything is fairly small and driver specific"

* tag 'spi-fix-v5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: npcm-fiu: Don't leak SPI master in probe error path
  spi: dw: Set transfer handler before unmasking the IRQs
  spi: cadence-quadspi: Fix error return code in cqspi_probe
  spi: bcm2835aux: Restore err assignment in bcm2835aux_spi_probe
  spi: lpspi: Fix use-after-free on unbind
  spi: bcm-qspi: Fix use-after-free on unbind
  spi: bcm2835aux: Fix use-after-free on unbind
  spi: bcm2835: Fix use-after-free on unbind
  spi: Introduce device-managed SPI controller allocation
  spi: fsi: Fix transfer returning without finalizing message
  spi: fix client driver breakages when using GPIO descriptors

Karsten Graul says:

====================
net/smc: fixes 2020-11-18

Patch 1 fixes the matching of link groups because with SMC-Dv2 the vlanid
should no longer be part of this matching. Patch 2 removes a sparse message.
====================

Link: https://lore.kernel.org/r/20201118214038.24039-1-kgraul@linux.ibm.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Sparse complaints 3 times about:
net/smc/smc_ib.c:203:52: warning: incorrect type in argument 1 (different address spaces)
net/smc/smc_ib.c:203:52:    expected struct net_device const *dev
net/smc/smc_ib.c:203:52:    got struct net_device [noderef] __rcu *const ndev

Fix that by using the existing and validated ndev variable instead of
accessing attr->ndev directly.

Fixes: 5102eca9 ("net/smc: Use rdma_read_gid_l2_fields to L2 fields")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

With the multi-subnet support of SMC-Dv2 the match for existing link
groups should not include the vlanid of the network device.
Set ini->smcd_version accordingly before the call to smc_conn_create()
and use this value in smc_conn_create() to skip the vlanid check.

Fixes: 5c21c4cc ("net/smc: determine accepted ISM devices")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Merge tag 'regulator-fix-v5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator

Pull regulator fixes from Mark Brown:
 "Mostly core fixes here, one set from Michał Mirosław which cleans up
  some issues introduced as part of the coupled regulators work, one
  memory leak during probe and two due to regulators which have an input
  supply name and regulator name which are identical, which is very
  unusual.

  There's also a fix for our handling of the similarly unusual case
  where we can't determine if a regulator is enabled during boot"

* tag 'regulator-fix-v5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: ti-abb: Fix array out of bound read access on the first transition
  regulator: workaround self-referent regulators
  regulator: avoid resolve_supply() infinite recursion
  regulator: fix memory leak with repeated set_machine_constraints()
  regulator: pfuze100: limit pfuze-support-disable-sw to pfuze{100,200}
  regulator: core: don't disable regulator if is_enabled return error.

IPV6=m
NF_DEFRAG_IPV6=y

ld: net/ipv6/netfilter/nf_conntrack_reasm.o: in function
`nf_ct_frag6_gather':
net/ipv6/netfilter/nf_conntrack_reasm.c:462: undefined reference to
`ipv6_frag_thdr_truncated'

Netfilter is depending on ipv6 symbol ipv6_frag_thdr_truncated. This
dependency is forcing IPV6=y.

Remove this dependency by moving ipv6_frag_thdr_truncated out of ipv6. This
is the same solution as used with a similar issues: Referring to
commit 70b095c8 ("ipv6: remove dependency of nf_defrag_ipv6 on ipv6
module")

Fixes: 9d9e937b ("ipv6/netfilter: Discard first fragment not including all headers")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Georg Kohmann <geokohma@cisco.com>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://lore.kernel.org/r/20201119095833.8409-1-geokohma@cisco.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Pull thermal fix from Daniel Lezcano:
 "Disable the CPU PM notifier for OMAP4430 for suspend in order to
  prevent wrong temperature leading to a critical shutdown (Peter
  Ujfalusi)"

* tag 'thermal-v5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux:
  thermal: ti-soc-thermal: Disable the CPU PM notifier for OMAP4430

We remove "other info" from "readelf -s --wide" output when
parsing GLOBAL_SYM_COUNT variable, which was added in [1].
But we don't do that for VERSIONED_SYM_COUNT and it's failing
the check_abi target on powerpc Fedora 33.

The extra "other info" wasn't problem for VERSIONED_SYM_COUNT
parsing until commit [2] added awk in the pipe, which assumes
that the last column is symbol, but it can be "other info".

Adding "other info" removal for VERSIONED_SYM_COUNT the same
way as we did for GLOBAL_SYM_COUNT parsing.

[1] aa915931 ("libbpf: Fix readelf output parsing for Fedora")
[2] 746f534a ("tools/libbpf: Avoid counting local symbols in ABI check")

Fixes: 746f534a ("tools/libbpf: Avoid counting local symbols in ABI check")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201118211350.1493421-1-jolsa@kernel.org

* acpi-fan:
  ACPI: fan: Initialize performance state sysfs attribute

* pm-cpuidle:
  cpuidle: tegra: Annotate tegra_pm_set_cpu_in_lp2() with RCU_NONIDLE

pseries|pnv_setup_rfi_flush already does the count cache flush setup, and
we just added entry and uaccess flushes. So the name is not very accurate
any more. In both platforms we then also immediately setup the STF flush.

Rename them to _setup_security_mitigations and fold the STF flush in.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

For simplicity in backporting, the original entry_flush test contained
a lot of duplicated code from the rfi_flush test. De-duplicate that code.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add a test modelled on the RFI flush test which counts the number
of L1D misses doing a simple syscall with the entry flush on and off.

For simplicity of backporting, this test duplicates a lot of code from
rfi_flush. We clean that up in the next patch.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

In kup.h we currently include kup-radix.h for all 64-bit builds, which
includes Book3S and Book3E. The latter doesn't make sense, Book3E
never uses the Radix MMU.

This has worked up until now, but almost by accident, and the recent
uaccess flush changes introduced a build breakage on Book3E because of
the bad structure of the code.

So disentangle things so that we only use kup-radix.h for Book3S. This
requires some more stubs in kup.h and fixing an include in
syscall_64.c.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

IBM Power9 processors can speculatively operate on data in the L1 cache
before it has been completely validated, via a way-prediction mechanism. It
is not possible for an attacker to determine the contents of impermissible
memory using this method, since these systems implement a combination of
hardware and software security measures to prevent scenarios where
protected data could be leaked.

However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that
the attacker controls. This can be used for example to speculatively bypass
"kernel user access prevention" techniques, as discovered by Anthony
Steinhauser of Google's Safeside Project. This is not an attack by itself,
but there is a possibility it could be used in conjunction with
side-channels or other weaknesses in the privileged code to construct an
attack.

This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This patch flushes the L1 cache after user accesses.

This is part of the fix for CVE-2020-4788.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

IBM Power9 processors can speculatively operate on data in the L1 cache
before it has been completely validated, via a way-prediction mechanism. It
is not possible for an attacker to determine the contents of impermissible
memory using this method, since these systems implement a combination of
hardware and software security measures to prevent scenarios where
protected data could be leaked.

However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that
the attacker controls. This can be used for example to speculatively bypass
"kernel user access prevention" techniques, as discovered by Anthony
Steinhauser of Google's Safeside Project. This is not an attack by itself,
but there is a possibility it could be used in conjunction with
side-channels or other weaknesses in the privileged code to construct an
attack.

This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This patch flushes the L1 cache on kernel entry.

This is part of the fix for CVE-2020-4788.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

We are about to add an entry flush. The rfi (exit) flush test measures
the number of L1D flushes over a syscall with the RFI flush enabled and
disabled. But if the entry flush is also enabled, the effect of enabling
and disabling the RFI flush is masked.

If there is a debugfs entry for the entry flush, disable it during the RFI
flush and restore it later.
Reported-by: Spoorthy S <spoorts2@in.ibm.com>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Merge tag 'linux-can-fixes-for-5.10-20201118' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2020-11-18

Jimmy Assarsson provides two patches for the kvaser_pciefd and kvaser_usb
drivers, where the can_bittiming_const are fixed.

The next patch is by me and fixes an erroneous flexcan_transceiver_enable()
during bus-off recovery in the flexcan driver.

Jarkko Nikula's patch for the m_can driver fixes the IRQ handler to only
process the interrupts if the device is not suspended.

* tag 'linux-can-fixes-for-5.10-20201118' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can:
  can: m_can: process interrupt only when not runtime suspended
  can: flexcan: flexcan_chip_start(): fix erroneous flexcan_transceiver_enable() during bus-off recovery
  can: kvaser_usb: kvaser_usb_hydra: Fix KCAN bittiming limits
  can: kvaser_pciefd: Fix KCAN bittiming limits
====================

Link: https://lore.kernel.org/r/20201118160414.2731659-1-mkl@pengutronix.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Slave function read the following capabilities from the wrong offset:
1. log_mc_entry_sz
2. fs_log_entry_sz
3. log_mc_hash_sz

Fix that by adjusting these capabilities offset to match firmware
layout.

Due to the wrong offset read, the following issues might occur:
1+2. Negative value reported at max_mcast_qp_attach.
3. Driver to init FW with multicast hash size of zero.

Fixes: a40ded60 ("net/mlx4_core: Add masking for a few queries on HCA caps")
Signed-off-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Eran Ben Elisha <eranbe@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/20201118081922.553-1-tariqt@nvidia.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Saeed Mahameed says:

====================
mlx5 fixes 2020-11-17

This series introduces some fixes to mlx5 driver.

* tag 'mlx5-fixes-2020-11-17' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux:
  net/mlx5: fix error return code in mlx5e_tc_nic_init()
  net/mlx5: E-Switch, Fail mlx5_esw_modify_vport_rate if qos disabled
  net/mlx5: Disable QoS when min_rates on all VFs are zero
  net/mlx5: Clear bw_share upon VF disable
  net/mlx5: Add handling of port type in rule deletion
  net/mlx5e: Fix check if netdev is bond slave
  net/mlx5e: Fix IPsec packet drop by mlx5e_tc_update_skb
  net/mlx5e: Set IPsec WAs only in IP's non checksum partial case.
  net/mlx5e: Fix refcount leak on kTLS RX resync
====================

Link: https://lore.kernel.org/r/20201117195702.386113-1-saeedm@nvidia.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The `skb' is mapped for DMA in ns_send() but does not unmap DMA in case
push_scqe() fails to submit the `skb'. The memory of the `skb' is
released so only the DMA mapping is leaking.

Unmap the DMA mapping in case push_scqe() failed.

Fixes: 864a3ff6 ("atm: [nicstar] remove virt_to_bus() and support 64-bit platforms")
Cc: Chas Williams <3chas3@gmail.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The ethernet driver may allocate skb (and skb->data) via napi_alloc_skb().
This ends up to page_frag_alloc() to allocate skb->data from
page_frag_cache->va.

During the memory pressure, page_frag_cache->va may be allocated as
pfmemalloc page. As a result, the skb->pfmemalloc is always true as
skb->data is from page_frag_cache->va. The skb will be dropped if the
sock (receiver) does not have SOCK_MEMALLOC. This is expected behaviour
under memory pressure.

However, once kernel is not under memory pressure any longer (suppose large
amount of memory pages are just reclaimed), the page_frag_alloc() may still
re-use the prior pfmemalloc page_frag_cache->va to allocate skb->data. As a
result, the skb->pfmemalloc is always true unless page_frag_cache->va is
re-allocated, even if the kernel is not under memory pressure any longer.

Here is how kernel runs into issue.

1. The kernel is under memory pressure and allocation of
PAGE_FRAG_CACHE_MAX_ORDER in __page_frag_cache_refill() will fail. Instead,
the pfmemalloc page is allocated for page_frag_cache->va.

2: All skb->data from page_frag_cache->va (pfmemalloc) will have
skb->pfmemalloc=true. The skb will always be dropped by sock without
SOCK_MEMALLOC. This is an expected behaviour.

3. Suppose a large amount of pages are reclaimed and kernel is not under
memory pressure any longer. We expect skb->pfmemalloc drop will not happen.

4. Unfortunately, page_frag_alloc() does not proactively re-allocate
page_frag_alloc->va and will always re-use the prior pfmemalloc page. The
skb->pfmemalloc is always true even kernel is not under memory pressure any
longer.

Fix this by freeing and re-allocating the page instead of recycling it.

References: https://lore.kernel.org/lkml/20201103193239.1807-1-dongli.zhang@oracle.com/
References: https://lore.kernel.org/linux-mm/20201105042140.5253-1-willy@infradead.org/Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Cc: Bert Barbe <bert.barbe@oracle.com>
Cc: Rama Nichanamatlu <rama.nichanamatlu@oracle.com>
Cc: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
Cc: Manjunath Patil <manjunath.b.patil@oracle.com>
Cc: Joe Jin <joe.jin@oracle.com>
Cc: SRINIVAS <srinivas.eeda@oracle.com>
Fixes: 79930f58 ("net: do not deplete pfmemalloc reserve")
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20201115201029.11903-1-dongli.zhang@oracle.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Pull gfs2 fix from Andreas Gruenbacher:
 "Fix gfs2 freeze/thaw"

* tag 'gfs2-v5.10-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  gfs2: Fix regression in freeze_go_sync

Pull nfsd fix from Bruce Fields:
 "Just one quick fix for a tracing oops"

* tag 'nfsd-5.10-2' of git://linux-nfs.org/~bfields/linux:
  SUNRPC: Fix oops in the rpc_xdr_buf event class

Merge tag 'linux-kselftest-kunit-fixes-5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kunit fixes from Shuah Khan:
 "Several fixes to Kunit documentation and tools, and to not pollute
  the source directory.

  Also remove the incorrect kunit .gitattributes file"

* tag 'linux-kselftest-kunit-fixes-5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  kunit: fix display of failed expectations for strings
  kunit: tool: fix extra trailing \n in raw + parsed test output
  kunit: tool: print out stderr from make (like build warnings)
  KUnit: Docs: usage: wording fixes
  KUnit: Docs: style: fix some Kconfig example issues
  KUnit: Docs: fix a wording typo
  kunit: Do not pollute source directory with generated files (test.log)
  kunit: Do not pollute source directory with generated files (.kunitconfig)
  kunit: tool: fix pre-existing python type annotation errors
  kunit: Fix kunit.py parse subcommand (use null build_dir)
  kunit: tool: unmark test_data as binary blobs