Since we pass an initialized struct tpm_buf instance in every call site
now, it is cleaner to pass that directly to the tpm_transmit_cmd() as
the TPM command/response buffer.

Fine-tune a little bit tpm_transmit() and tpm_transmit_cmd() comments
while doing this.
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Tested-by: Alexander Steffen <Alexander.Steffen@infineon.com>

Set tpm_chip->timeouts_adjusted directly in the update_timeouts
code instead of returning bool. In case of tpm read failing
print warning that the read failed and continue on.
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Currently tpm_transmit_cmd will print an error message if the tpm
returns something other than TPM2_RC_SUCCESS. This means that if the
tpm returns that it is testing an error message will be printed, and
this can cause confusion for the end user. So avoid printing the error
message if TPM2_RC_TESTING is the return code.

Cc: Peter Huewe <peterhuewe@gmx.de>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

TCG defines two structures, TCG_EfiSpecIDEventStruct and TCG_PCR_EVENT2,
which contain variable-sized arrays in the middle of the definition.

Since these structures are not suitable for type casting, this patch
removes structure members after the variable-sized arrays and adds the
_head suffix to the structure name, to indicate that the renamed structures
do not contain all fields defined by TCG.

Lastly, given that variable-sized arrays are now in the last position, and
given that the size of the arrays cannot be determined in advance, this
patch also sets the size of those arrays to zero and removes the definition
of TPM2_ACTIVE_PCR_BANKS.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

It is unable to read the entry when it is the only one in
binary_bios_measurements:

00000000  00 00 00 00 08 00 00 00  c4 2f ed ad 26 82 00 cb
00000010  1d 15 f9 78 41 c3 44 e7  9d ae 33 20 00 00 00 00
00000020

This is obviously a firmware problem on my linux machine:

	Manufacturer: Inspur
	Product Name: SA5212M4
	Version: 01

However, binary_bios_measurements should return it any way,
rather than nothing, after all its content is completely
valid.

Fixes: 55a82ab3 ("tpm: add bios measurement log")
Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Reviewd-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

The responsibility of tpm1_bios_measurements_start() is to walk over the
first *pos measurements, ensuring the skipped and to-be-read
measurements are not out-of-boundary.

This commit simplifies the loop by employing a do-while loop with
the necessary sanity check.
Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Reviewd-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Return -E2BIG when the transfer is incomplete. The upper layer does
not retry, so not doing that is incorrect behaviour.

Cc: stable@vger.kernel.org
Fixes: a2871c62 ("tpm: Add support for Atmel I2C TPMs")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>

The send() callback should never return length as it does not in every
driver except tpm_crb in the success case. The reason is that the main
transmit functionality only cares about whether the transmit was
successful or not and ignores the count completely.
Suggested-by: Stefan Berger <stefanb@linux.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Tested-by: Alexander Steffen <Alexander.Steffen@infineon.com>

Added the tests that I've been using for testing TPM 2.0 functionality
for a long time but have been out-of-tree so far, residing in

https://github.com/jsakkine-intel/tpm2-scripts

Cc: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Acked-by: Joey Pabalinas <joeypabalinas@gmail.com>
Reviewed-by: Petr Vorel <petr.vorel@gmail.com>

* Rename TPM_BUFSIZE defined in drivers/char/tpm/st33zp24/st33zp24.h to
  ST33ZP24_BUFSIZE.
* Rename TPM_BUFSIZE defined in drivers/char/tpm/tpm_i2c_infineon.c to
  TPM_I2C_INFINEON_BUFSIZE.
* Rename TPM_RETRY in tpm_i2c_nuvoton to TPM_I2C_RETRIES.
* Remove TPM_HEADER_SIZE from tpm_i2c_nuvoton.

Cc: stable@vger.kernel.org
Fixes: bf38b871 ("tpm/tpm_i2c_stm_st33: Split tpm_i2c_tpm_st33 in 2 layers (core + phy)")
Fixes: aad628c1 ("char/tpm: Add new driver for Infineon I2C TIS TPM")
Fixes: 32d33b29 ("TPM: Retry SaveState command in suspend path")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

The current approach to read first 6 bytes from the response and then tail
of the response, can cause the 2nd memcpy_fromio() to do an unaligned read
(e.g. read 32-bit word from address aligned to a 16-bits), depending on how
memcpy_fromio() is implemented. If this happens, the read will fail and the
memory controller will fill the read with 1's.

This was triggered by 170d13ca, which should be probably refined to
check and react to the address alignment. Before that commit, on x86
memcpy_fromio() turned out to be memcpy(). By a luck GCC has done the right
thing (from tpm_crb's perspective) for us so far, but we should not rely on
that. Thus, it makes sense to fix this also in tpm_crb, not least because
the fix can be then backported to stable kernels and make them more robust
when compiled in differing environments.

Cc: stable@vger.kernel.org
Cc: James Morris <jmorris@namei.org>
Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: Jerry Snitselaar <jsnitsel@redhat.com>
Fixes: 30fc8d13 ("tpm: TPM 2.0 CRB Interface")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Acked-by: Tomas Winkler <tomas.winkler@intel.com>

The include for asm/syscall.h was needed in a prior version of lsm.c
that checked return values of syscall_get_nr, but since we did away with
that part of the code this include is no longer necessary. Take out this
include since it breaks builds for certain architectures. We no longer
have any arch-specific code in SafeSetID.
Signed-off-by: Micah Morton <mortonm@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

This patch changes the Kconfig file for the SafeSetID LSM to depend on
CONFIG_SECURITY as well as select CONFIG_SECURITYFS, since the policies
for the LSM are configured through writing to securityfs.
Signed-off-by: Micah Morton <mortonm@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

Without this, system boot was crashing with:

[0.174285] LSM: Security Framework initializing
[0.175277] BUG: unable to handle kernel NULL pointer dereference
...
[0.176272] Call Trace:
[0.176272]  ordered_lsm_parse+0x112/0x20b
[0.176272]  security_init+0x9b/0x3ab
[0.176272]  start_kernel+0x413/0x479
[0.176272]  secondary_startup_64+0xa4/0xb0
Signed-off-by: Micah Morton <mortonm@chromium.org>
Fixed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

SafeSetID gates the setid family of syscalls to restrict UID/GID
transitions from a given UID/GID to only those approved by a
system-wide whitelist. These restrictions also prohibit the given
UIDs/GIDs from obtaining auxiliary privileges associated with
CAP_SET{U/G}ID, such as allowing a user to set up user namespace UID
mappings. For now, only gating the set*uid family of syscalls is
supported, with support for set*gid coming in a future patch set.
Signed-off-by: Micah Morton <mortonm@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

This change ensures that the set*uid family of syscalls in kernel/sys.c
(setreuid, setuid, setresuid, setfsuid) all call ns_capable_common with
the CAP_OPT_INSETID flag, so capability checks in the security_capable
hook can know whether they are being called from within a set*uid
syscall. This change is a no-op by itself, but is needed for the
proposed SafeSetID LSM.
Signed-off-by: Micah Morton <mortonm@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

Being able to specify multiple "use_group" lines makes it
easier to write whitelisted policies.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <james.morris@microsoft.com>

Follow many of recommendations by scripts/checkpatch.pl, and follow
"lift switch variables out of switches" by Kees Cook.
This patch makes no functional change.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <james.morris@microsoft.com>

TOMOYO security module is designed to use "struct task_struct"->security
in order to allow per "struct task_struct" tracking without being disturbed
by unable to update "struct cred"->security due to override mechanism.

Now that infrastructure-managed security blob is ready, this patch updates
TOMOYO to use "struct task_struct"->security.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <james.morris@microsoft.com>

There is a plan to build the kernel with -Wimplicit-fallthrough and
these places in the code produced warnings (W=1). Fix them up.

This commit remove the following warnings:

  security/keys/request_key.c:293:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
  security/keys/request_key.c:298:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
  security/keys/request_key.c:307:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

There is a plan to build the kernel with -Wimplicit-fallthrough and
these places in the code produced warnings (W=1). Fix them up.

This commit remove the following warning:

  security/keys/process_keys.c:380:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
  security/keys/process_keys.c:404:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
  security/keys/process_keys.c:424:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

There is a plan to build the kernel with -Wimplicit-fallthrough and
this place in the code produced a warning (W=1).

This commit remove the following warning:

  security/keys/keyring.c:248:10: warning: this statement may fall through [-Wimplicit-fallthrough=]
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

There is a plan to build the kernel with -Wimplicit-fallthrough and
this place in the code produced a warning (W=1).

In this particular case change put the fall through comment on a single
line so as to match the regular expression expected by GCC.

This commit remove the following warning:

  kernel/capability.c:95:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

AppArmor will no longer be the only user of task blob
after TOMOYO started using task blob.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: f4ad8f2c ("LSM: Infrastructure management of the task security")
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

Sync to Linux 5.0-rc3 to pull in the VFS changes which impacted a lot
of the LSM code.

Pull pstore fixes from Kees Cook:

 - Fix console ramoops to show the previous boot logs (Sai Prakash
   Ranjan)

 - Avoid allocation and leak of platform data

* tag 'pstore-v5.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore/ram: Avoid allocation and leak of platform data
  pstore/ram: Fix console ramoops to show the previous boot logs

Pull gcc-plugins fixes from Kees Cook:
 "Fix ARM per-task stack protector plugin under GCC 9 (Ard Biesheuvel)"

* tag 'gcc-plugins-v5.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  gcc-plugins: arm_ssp_per_task_plugin: fix for GCC 9+
  gcc-plugins: arm_ssp_per_task_plugin: sign extend the SP mask

Pull networking fixes from David Miller:

 1) Fix endless loop in nf_tables, from Phil Sutter.

 2) Fix cross namespace ip6_gre tunnel hash list corruption, from
    Olivier Matz.

 3) Don't be too strict in phy_start_aneg() otherwise we might not allow
    restarting auto negotiation. From Heiner Kallweit.

 4) Fix various KMSAN uninitialized value cases in tipc, from Ying Xue.

 5) Memory leak in act_tunnel_key, from Davide Caratti.

 6) Handle chip errata of mv88e6390 PHY, from Andrew Lunn.

 7) Remove linear SKB assumption in fou/fou6, from Eric Dumazet.

 8) Missing udplite rehash callbacks, from Alexey Kodanev.

 9) Log dirty pages properly in vhost, from Jason Wang.

10) Use consume_skb() in neigh_probe() as this is a normal free not a
    drop, from Yang Wei. Likewise in macvlan_process_broadcast().

11) Missing device_del() in mdiobus_register() error paths, from Thomas
    Petazzoni.

12) Fix checksum handling of short packets in mlx5, from Cong Wang.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (96 commits)
  bpf: in __bpf_redirect_no_mac pull mac only if present
  virtio_net: bulk free tx skbs
  net: phy: phy driver features are mandatory
  isdn: avm: Fix string plus integer warning from Clang
  net/mlx5e: Fix cb_ident duplicate in indirect block register
  net/mlx5e: Fix wrong (zero) TX drop counter indication for representor
  net/mlx5e: Fix wrong error code return on FEC query failure
  net/mlx5e: Force CHECKSUM_UNNECESSARY for short ethernet frames
  tools: bpftool: Cleanup license mess
  bpf: fix inner map masking to prevent oob under speculation
  bpf: pull in pkt_sched.h header for tooling to fix bpftool build
  selftests: forwarding: Add a test case for externally learned FDB entries
  selftests: mlxsw: Test FDB offload indication
  mlxsw: spectrum_switchdev: Do not treat static FDB entries as sticky
  net: bridge: Mark FDB entries that were added by user as such
  mlxsw: spectrum_fid: Update dummy FID index
  mlxsw: pci: Return error on PCI reset timeout
  mlxsw: pci: Increase PCI SW reset timeout
  mlxsw: pci: Ring CQ's doorbell before RDQ's
  MAINTAINERS: update email addresses of liquidio driver maintainers
  ...

Yue Hu noticed that when parsing device tree the allocated platform data
was never freed. Since it's not used beyond the function scope, this
switches to using a stack variable instead.
Reported-by: Yue Hu <huyue2@yulong.com>
Fixes: 35da6094 ("pstore/ram: add Device Tree bindings")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

GCC 9 reworks the way the references to the stack canary are
emitted, to prevent the value from being spilled to the stack
before the final comparison in the epilogue, defeating the
purpose, given that the spill slot is under control of the
attacker that we are protecting ourselves from.

Since our canary value address is obtained without accessing
memory (as opposed to pre-v7 code that will obtain it from a
literal pool), it is unlikely (although not guaranteed) that
the compiler will spill the canary value in the same way, so
let's just disable this improvement when building with GCC9+.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

The ARM per-task stack protector GCC plugin hits an assert in
the compiler in some case, due to the fact the the SP mask
expression is not sign-extended as it should be. So fix that.
Suggested-by: Kugan Vivekanandarajah <kugan.vivekanandarajah@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

Pull virtio/vhost fixes and cleanups from Michael Tsirkin:
 "Fixes and cleanups all over the place"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost/scsi: Use copy_to_iter() to send control queue response
  vhost: return EINVAL if iovecs size does not match the message size
  virtio-balloon: tweak config_changed implementation
  virtio: don't allocate vqs when names[i] = NULL
  virtio_pci: use queue idx instead of array idx to set up the vq
  virtio: document virtio_config_ops restrictions
  virtio: fix virtio_config_ops description

Pull btrfs fixes from David Sterba:
 "A handful of fixes (some of them in testing for a long time):

   - fix some test failures regarding cleanup after transaction abort

   - revert of a patch that could cause a deadlock

   - delayed iput fixes, that can help in ENOSPC situation when there's
     low space and a lot data to write"

* tag 'for-5.0-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: wakeup cleaner thread when adding delayed iput
  btrfs: run delayed iputs before committing
  btrfs: wait on ordered extents on abort cleanup
  btrfs: handle delayed ref head accounting cleanup in abort
  Revert "btrfs: balance dirty metadata pages in btrfs_finish_ordered_io"

Merge tags 'compiler-attributes-for-linus-v5.0-rc3' and 'clang-format-for-linus-v5.0-rc3' of git://github.com/ojeda/linux

Pull misc clang fixes from Miguel Ojeda:

  - A fix for OPTIMIZER_HIDE_VAR from Michael S Tsirkin

  - Update clang-format with the latest for_each macro list from Jason
    Gunthorpe

* tag 'compiler-attributes-for-linus-v5.0-rc3' of git://github.com/ojeda/linux:
  include/linux/compiler*.h: fix OPTIMIZER_HIDE_VAR

* tag 'clang-format-for-linus-v5.0-rc3' of git://github.com/ojeda/linux:
  clang-format: Update .clang-format with the latest for_each macro list

If an input number x for int_sqrt64() has the highest bit set, then
fls64(x) is 64.  (1UL << 64) is an overflow and breaks the algorithm.

Subtracting 1 is a better guess for the initial value of m anyway and
that's what also done in int_sqrt() implicitly [*].

[*] Note how int_sqrt() uses __fls() with two underscores, which already
    returns the proper raw bit number.

    In contrast, int_sqrt64() used fls64(), and that returns bit numbers
    illogically starting at 1, because of error handling for the "no
    bits set" case. Will points out that he bug probably is due to a
    copy-and-paste error from the regular int_sqrt() case.
Signed-off-by: Florian La Roche <Florian.LaRoche@googlemail.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 594cc251 ("make 'user_access_begin()' do 'access_ok()'")
makes the access_ok() check part of the user_access_begin() preceding a
series of 'unsafe' accesses.  This has the desirable effect of ensuring
that all 'unsafe' accesses have been range-checked, without having to
pick through all of the callsites to verify whether the appropriate
checking has been made.

However, the consolidated range check does not inhibit speculation, so
it is still up to the caller to ensure that they are not susceptible to
any speculative side-channel attacks for user addresses that ultimately
fail the access_ok() check.

This is an oversight, so use __uaccess_begin_nospec() to ensure that
speculation is inhibited until the access_ok() check has passed.
Reported-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull arm64 fixes from Will Deacon:
 "Three arm64 fixes for -rc3.

  We've plugged a couple of nasty issues involving KASLR-enabled
  kernels, and removed a redundant #define that was introduced as part
  of the KHWASAN fixes from akpm at -rc2.

   - Fix broken kpti page-table rewrite in bizarre KASLR configuration

   - Fix module loading with KASLR

   - Remove redundant definition of ARCH_SLAB_MINALIGN"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  kasan, arm64: remove redundant ARCH_SLAB_MINALIGN define
  arm64: kaslr: ensure randomized quantities are clean to the PoC
  arm64: kpti: Update arm64_kernel_use_ng_mappings() when forced on

Daniel Borkmann says:

====================
pull-request: bpf 2019-01-20

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Fix a out-of-bounds access in __bpf_redirect_no_mac, from Willem.

2) Fix bpf_setsockopt to reset sock dst on SO_MARK changes, from Peter.

3) Fix map in map masking to prevent out-of-bounds access under
   speculative execution, from Daniel.

4) Fix bpf_setsockopt's SO_MAX_PACING_RATE to support TCP internal
   pacing, from Yuchung.

5) Fix json writer license in bpftool, from Thomas.

6) Fix AF_XDP to check if an actually queue exists during umem
   setup, from Krzysztof.

7) Several fixes to BPF stackmap's build id handling. Another fix
   for bpftool build to account for libbfd variations wrt linking
   requirements, from Stanislav.

8) Fix BPF samples build with clang by working around missing asm
   goto, from Yonghong.

9) Fix libbpf to retry program load on signal interrupt, from Lorenz.

10) Various minor compile warning fixes in BPF code, from Mathieu.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Syzkaller was able to construct a packet of negative length by
redirecting from bpf_prog_test_run_skb with BPF_PROG_TYPE_LWT_XMIT:

    BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:345 [inline]
    BUG: KASAN: slab-out-of-bounds in skb_copy_from_linear_data include/linux/skbuff.h:3421 [inline]
    BUG: KASAN: slab-out-of-bounds in __pskb_copy_fclone+0x2dd/0xeb0 net/core/skbuff.c:1395
    Read of size 4294967282 at addr ffff8801d798009c by task syz-executor2/12942

    kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
    check_memory_region_inline mm/kasan/kasan.c:260 [inline]
    check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
    memcpy+0x23/0x50 mm/kasan/kasan.c:302
    memcpy include/linux/string.h:345 [inline]
    skb_copy_from_linear_data include/linux/skbuff.h:3421 [inline]
    __pskb_copy_fclone+0x2dd/0xeb0 net/core/skbuff.c:1395
    __pskb_copy include/linux/skbuff.h:1053 [inline]
    pskb_copy include/linux/skbuff.h:2904 [inline]
    skb_realloc_headroom+0xe7/0x120 net/core/skbuff.c:1539
    ipip6_tunnel_xmit net/ipv6/sit.c:965 [inline]
    sit_tunnel_xmit+0xe1b/0x30d0 net/ipv6/sit.c:1029
    __netdev_start_xmit include/linux/netdevice.h:4325 [inline]
    netdev_start_xmit include/linux/netdevice.h:4334 [inline]
    xmit_one net/core/dev.c:3219 [inline]
    dev_hard_start_xmit+0x295/0xc90 net/core/dev.c:3235
    __dev_queue_xmit+0x2f0d/0x3950 net/core/dev.c:3805
    dev_queue_xmit+0x17/0x20 net/core/dev.c:3838
    __bpf_tx_skb net/core/filter.c:2016 [inline]
    __bpf_redirect_common net/core/filter.c:2054 [inline]
    __bpf_redirect+0x5cf/0xb20 net/core/filter.c:2061
    ____bpf_clone_redirect net/core/filter.c:2094 [inline]
    bpf_clone_redirect+0x2f6/0x490 net/core/filter.c:2066
    bpf_prog_41f2bcae09cd4ac3+0xb25/0x1000

The generated test constructs a packet with mac header, network
header, skb->data pointing to network header and skb->len 0.

Redirecting to a sit0 through __bpf_redirect_no_mac pulls the
mac length, even though skb->data already is at skb->network_header.
bpf_prog_test_run_skb has already pulled it as LWT_XMIT !is_l2.

Update the offset calculation to pull only if skb->data differs
from skb->network_header, which is not true in this case.

The test itself can be run only from commit 1cf1cae9 ("bpf:
introduce BPF_PROG_TEST_RUN command"), but the same type of packets
with skb at network header could already be built from lwt xmit hooks,
so this fix is more relevant to that commit.

Also set the mac header on redirect from LWT_XMIT, as even after this
change to __bpf_redirect_no_mac that field is expected to be set, but
is not yet in ip_finish_output2.

Fixes: 3a0af8fd ("bpf: BPF for lightweight tunnel infrastructure")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>