Merge tag 'arm64-spectre-bhb-for-v5.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 spectre fixes from James Morse:
 "ARM64 Spectre-BHB mitigations:

   - Make EL1 vectors per-cpu

   - Add mitigation sequences to the EL1 and EL2 vectors on vulnerble
     CPUs

   - Implement ARCH_WORKAROUND_3 for KVM guests

   - Report Vulnerable when unprivileged eBPF is enabled"

* tag 'arm64-spectre-bhb-for-v5.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: proton-pack: Include unprivileged eBPF status in Spectre v2 mitigation reporting
  arm64: Use the clearbhb instruction in mitigations
  KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated
  arm64: Mitigate spectre style branch history side channels
  arm64: proton-pack: Report Spectre-BHB vulnerabilities as part of Spectre-v2
  arm64: Add percpu vectors for EL1
  arm64: entry: Add macro for reading symbol addresses from the trampoline
  arm64: entry: Add vectors that have the bhb mitigation sequences
  arm64: entry: Add non-kpti __bp_harden_el1_vectors for mitigations
  arm64: entry: Allow the trampoline text to occupy multiple pages
  arm64: entry: Make the kpti trampoline's kpti sequence optional
  arm64: entry: Move trampoline macros out of ifdef'd section
  arm64: entry: Don't assume tramp_vectors is the start of the vectors
  arm64: entry: Allow tramp_alias to access symbols after the 4K boundary
  arm64: entry: Move the trampoline data page before the text page
  arm64: entry: Free up another register on kpti's tramp_exit path
  arm64: entry: Make the trampoline cleanup optional
  KVM: arm64: Allow indirect vectors to be used without SPECTRE_V3A
  arm64: spectre: Rename spectre_v4_patch_fw_mitigation_conduit
  arm64: entry.S: Add ventry overflow sanity checks

Pull ARM spectre fixes from Russell King:
 "ARM Spectre BHB mitigations.

  These patches add Spectre BHB migitations for the following Arm CPUs
  to the 32-bit ARM kernels:
   - Cortex A15
   - Cortex A57
   - Cortex A72
   - Cortex A73
   - Cortex A75
   - Brahma B15
  for CVE-2022-23960"

* tag 'for-linus-bhb' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: include unprivileged BPF status in Spectre V2 reporting
  ARM: Spectre-BHB workaround
  ARM: use LOADADDR() to get load address of sections
  ARM: early traps initialisation
  ARM: report Spectre v2 status through sysfs

The mitigations for Spectre-BHB are only applied when an exception
is taken, but when unprivileged BPF is enabled, userspace can
load BPF programs that can be used to exploit the problem.

When unprivileged BPF is enabled, report the vulnerable status via
the spectre_v2 sysfs file.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Pull x86 spectre fixes from Borislav Petkov:

 - Mitigate Spectre v2-type Branch History Buffer attacks on machines
   which support eIBRS, i.e., the hardware-assisted speculation
   restriction after it has been shown that such machines are vulnerable
   even with the hardware mitigation.

 - Do not use the default LFENCE-based Spectre v2 mitigation on AMD as
   it is insufficient to mitigate such attacks. Instead, switch to
   retpolines on all AMD by default.

 - Update the docs and add some warnings for the obviously vulnerable
   cmdline configurations.

* tag 'x86_bugs_for_v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/speculation: Warn about eIBRS + LFENCE + Unprivileged eBPF + SMT
  x86/speculation: Warn about Spectre v2 LFENCE mitigation
  x86/speculation: Update link to AMD speculation whitepaper
  x86/speculation: Use generic retpoline by default on AMD
  x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting
  Documentation/hw-vuln: Update spectre doc
  x86/speculation: Add eIBRS + Retpoline options
  x86/speculation: Rename RETPOLINE_AMD to RETPOLINE_LFENCE

Pull MTD fix from Miquel Raynal:
 "As part of a previous changeset introducing support for the K3
  architecture, the OMAP_GPMC (a non visible symbol) got selected by the
  selection of MTD_NAND_OMAP2 instead of doing so from the architecture
  directly (like for the other users of these two drivers). Indeed, from
  a hardware perspective, the OMAP NAND controller needs the GPMC to
  work.

  This led to a robot error which got addressed in fix merge into -rc4.
  Unfortunately, the approach at this time still used "select" and lead
  to further build error reports (sparc64:allmodconfig).

  This time we switch to 'depends on' in order to prevent random
  misconfigurations. The different dependencies will however need a
  future cleanup"

* tag 'mtd/fixes-for-5.17-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
  mtd: rawnand: omap2: Actually prevent invalid configuration and build error

Pull virtio fixes from Michael Tsirkin:
 "Some last minute fixes that took a while to get ready. Not
  regressions, but they look safe and seem to be worth to have"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  tools/virtio: handle fallout from folio work
  tools/virtio: fix virtio_test execution
  vhost: remove avail_event arg from vhost_update_avail_event()
  virtio: drop default for virtio-mem
  vdpa: fix use-after-free on vp_vdpa_remove
  virtio-blk: Remove BUG_ON() in virtio_queue_rq()
  virtio-blk: Don't use MAX_DISCARD_SEGMENTS if max_discard_seg is zero
  vhost: fix hung thread due to erroneous iotlb entries
  vduse: Fix returning wrong type in vduse_domain_alloc_iova()
  vdpa/mlx5: add validation for VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command
  vdpa/mlx5: should verify CTRL_VQ feature exists for MQ
  vdpa: factor out vdpa_set_features_unlocked for vdpa internal use
  virtio_console: break out of buf poll on remove
  virtio: document virtio_reset_device
  virtio: acknowledge all features before access
  virtio: unexport virtio_finalize_features

Unfortunately, we ended up merging an old version of the patch "fix info
leak with DMA_FROM_DEVICE" instead of merging the latest one. Christoph
(the swiotlb maintainer), he asked me to create an incremental fix
(after I have pointed this out the mix up, and asked him for guidance).
So here we go.

The main differences between what we got and what was agreed are:
* swiotlb_sync_single_for_device is also required to do an extra bounce
* We decided not to introduce DMA_ATTR_OVERWRITE until we have exploiters
* The implantation of DMA_ATTR_OVERWRITE is flawed: DMA_ATTR_OVERWRITE
  must take precedence over DMA_ATTR_SKIP_CPU_SYNC

Thus this patch removes DMA_ATTR_OVERWRITE, and makes
swiotlb_sync_single_for_device() bounce unconditionally (that is, also
when dir == DMA_TO_DEVICE) in order do avoid synchronising back stale
data from the swiotlb buffer.

Let me note, that if the size used with dma_sync_* API is less than the
size used with dma_[un]map_*, under certain circumstances we may still
end up with swiotlb not being transparent. In that sense, this is no
perfect fix either.

To get this bullet proof, we would have to bounce the entire
mapping/bounce buffer. For that we would have to figure out the starting
address, and the size of the mapping in
swiotlb_sync_single_for_device(). While this does seem possible, there
seems to be no firm consensus on how things are supposed to work.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Fixes: ddbd89de ("swiotlb: fix info leak with DMA_FROM_DEVICE")
Cc: stable@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The mitigations for Spectre-BHB are only applied when an exception is
taken from user-space. The mitigation status is reported via the spectre_v2
sysfs vulnerabilities file.

When unprivileged eBPF is enabled the mitigation in the exception vectors
can be avoided by an eBPF program.

When unprivileged eBPF is enabled, print a warning and report vulnerable
via the sysfs vulnerabilities file.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>

The root of the problem is that we are selecting symbols that have
dependencies. This can cause random configurations that can fail.
The cleanest solution is to avoid using select.

This driver uses interfaces from the OMAP_GPMC driver so we have to
depend on it instead.

Fixes: 4cd335da ("mtd: rawnand: omap2: Prevent invalid configuration and build error")
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/linux-mtd/20220219193600.24892-1-rogerq@kernel.org

Pull btrfs fixes from David Sterba:
 "A few more fixes for various problems that have user visible effects
  or seem to be urgent:

   - fix corruption when combining DIO and non-blocking io_uring over
     multiple extents (seen on MariaDB)

   - fix relocation crash due to premature return from commit

   - fix quota deadlock between rescan and qgroup removal

   - fix item data bounds checks in tree-checker (found on a fuzzed
     image)

   - fix fsync of prealloc extents after EOF

   - add missing run of delayed items after unlink during log replay

   - don't start relocation until snapshot drop is finished

   - fix reversed condition for subpage writers locking

   - fix warning on page error"

* tag 'for-5.17-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fallback to blocking mode when doing async dio over multiple extents
  btrfs: add missing run of delayed items after unlink during log replay
  btrfs: qgroup: fix deadlock between rescan worker and remove qgroup
  btrfs: fix relocation crash due to premature return from btrfs_commit_transaction()
  btrfs: do not start relocation until in progress drops are done
  btrfs: tree-checker: use u64 for item data end to avoid overflow
  btrfs: do not WARN_ON() if we have PageError set
  btrfs: fix lost prealloc extents beyond eof after full fsync
  btrfs: subpage: fix a wrong check on subpage->writers

Pull kvm fixes from Paolo Bonzini:
 "x86 guest:

   - Tweaks to the paravirtualization code, to avoid using them when
     they're pointless or harmful

  x86 host:

   - Fix for SRCU lockdep splat

   - Brown paper bag fix for the propagation of errno"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: pull kvm->srcu read-side to kvm_arch_vcpu_ioctl_run
  KVM: x86/mmu: Passing up the error state of mmu_alloc_shadow_roots()
  KVM: x86: Yield to IPI target vCPU only if it is busy
  x86/kvmclock: Fix Hyper-V Isolated VM's boot issue when vCPUs > 64
  x86/kvm: Don't waste memory if kvmclock is disabled
  x86/kvm: Don't use PV TLB/yield when mwait is advertised

Pull powerpc fix from Michael Ellerman:
 "Fix build failure when CONFIG_PPC_64S_HASH_MMU is not set.

  Thanks to Murilo Opsfelder Araujo, and Erhard F"

* tag 'powerpc-5.17-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: Fix build failure when CONFIG_PPC_64S_HASH_MMU is not set

Pull tracing fixes from Steven Rostedt:

 - Fix sorting on old "cpu" value in histograms

 - Fix return value of __setup() boot parameter handlers

* tag 'trace-v5.17-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix return value of __setup handlers
  tracing/histogram: Fix sorting on old "cpu" value

just add a stub
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio_test hangs on __vring_new_virtqueue() because `vqs_list_lock`
is not initialized.

Let's initialize it in vdev_info_init().
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20220118150631.167015-1-sgarzare@redhat.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

In vhost_update_avail_event() we never used the `avail_event` argument,
since its introduction in commit 2723feaa ("vhost: set log when
updating used flags or avail event").

Let's remove it to clean up the code.
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20220113141134.186773-1-sgarzare@redhat.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

There's no special reason why virtio-mem needs a default that's
different from what kconfig provides, any more than e.g. virtio blk.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>

When vp_vdpa driver is unbind, vp_vdpa is freed in vdpa_unregister_device
and then vp_vdpa->mdev.pci_dev is dereferenced in vp_modern_remove,
triggering use-after-free.

Call Trace of unbinding driver free vp_vdpa :
do_syscall_64
  vfs_write
    kernfs_fop_write_iter
      device_release_driver_internal
        pci_device_remove
          vp_vdpa_remove
            vdpa_unregister_device
              kobject_release
                device_release
                  kfree

Call Trace of dereference vp_vdpa->mdev.pci_dev:
vp_modern_remove
  pci_release_selected_regions
    pci_release_region
      pci_resource_len
        pci_resource_end
          (dev)->resource[(bar)].end
Signed-off-by: Zhang Min <zhang.min9@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Link: https://lore.kernel.org/r/20220301091059.46869-1-wang.yi59@zte.com.cnSigned-off-by: Michael S. Tsirkin <mst@redhat.com>
Fixes: 64b9f64f ("vdpa: introduce virtio pci driver")
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

Currently we have a BUG_ON() to make sure the number of sg
list does not exceed queue_max_segments() in virtio_queue_rq().
However, the block layer uses queue_max_discard_segments()
instead of queue_max_segments() to limit the sg list for
discard requests. So the BUG_ON() might be triggered if
virtio-blk device reports a larger value for max discard
segment than queue_max_segments(). To fix it, let's simply
remove the BUG_ON() which has become unnecessary after commit
02746e26("virtio-blk: avoid preallocating big SGL for data").
And the unused vblk->sg_elems can also be removed together.

Fixes: 1f23816b ("virtio_blk: add discard and write zeroes support")
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Link: https://lore.kernel.org/r/20220304100058.116-2-xieyongji@bytedance.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

Currently the value of max_discard_segment will be set to
MAX_DISCARD_SEGMENTS (256) with no basis in hardware if device
set 0 to max_discard_seg in configuration space. It's incorrect
since the device might not be able to handle such large descriptors.
To fix it, let's follow max_segments restrictions in this case.

Fixes: 1f23816b ("virtio_blk: add discard and write zeroes support")
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Link: https://lore.kernel.org/r/20220304100058.116-1-xieyongji@bytedance.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

In vhost_iotlb_add_range_ctx(), range size can overflow to 0 when
start is 0 and last is ULONG_MAX. One instance where it can happen
is when userspace sends an IOTLB message with iova=size=uaddr=0
(vhost_process_iotlb_msg). So, an entry with size = 0, start = 0,
last = ULONG_MAX ends up in the iotlb. Next time a packet is sent,
iotlb_access_ok() loops indefinitely due to that erroneous entry.

	Call Trace:
	 <TASK>
	 iotlb_access_ok+0x21b/0x3e0 drivers/vhost/vhost.c:1340
	 vq_meta_prefetch+0xbc/0x280 drivers/vhost/vhost.c:1366
	 vhost_transport_do_send_pkt+0xe0/0xfd0 drivers/vhost/vsock.c:104
	 vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372
	 kthread+0x2e9/0x3a0 kernel/kthread.c:377
	 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
	 </TASK>

Reported by syzbot at:
	https://syzkaller.appspot.com/bug?extid=0abd373e2e50d704db87

To fix this, do two things:

1. Return -EINVAL in vhost_chr_write_iter() when userspace asks to map
   a range with size 0.
2. Fix vhost_iotlb_add_range_ctx() to handle the range [0, ULONG_MAX]
   by splitting it into two entries.

Fixes: 0bbe3066 ("vhost: factor out IOTLB")
Reported-by: syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com
Tested-by: syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
Link: https://lore.kernel.org/r/20220305095525.5145-1-mail@anirudhrb.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

Pull input updates from Dmitry Torokhov:

 - a fixup for Goodix touchscreen driver allowing it to work on certain
   Cherry Trail devices

 - a fix for imbalanced enable/disable regulator in Elam touchpad driver
   that became apparent when used with Asus TF103C 2-in-1 dock

 - a couple new input keycodes used on newer keyboards

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  HID: add mapping for KEY_ALL_APPLICATIONS
  HID: add mapping for KEY_DICTATE
  Input: elan_i2c - fix regulator enable count imbalance after suspend/resume
  Input: elan_i2c - move regulator_[en|dis]able() out of elan_[en|dis]able_power()
  Input: goodix - workaround Cherry Trail devices with a bogus ACPI Interrupt() resource
  Input: goodix - use the new soc_intel_is_byt() helper
  Input: samsung-keypad - properly state IOMEM dependency

Merge misc fixes from Andrew Morton:
 "8 patches.

  Subsystems affected by this patch series: mm (hugetlb, pagemap, and
  userfaultfd), memfd, selftests, and kconfig"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  configs/debug: set CONFIG_DEBUG_INFO=y properly
  proc: fix documentation and description of pagemap
  kselftest/vm: fix tests build with old libc
  memfd: fix F_SEAL_WRITE after shmem huge page allocated
  mm: fix use-after-free when anon vma name is used after vma is freed
  mm: prevent vm_area_struct::anon_name refcount saturation
  mm: refactor vm_area_struct::anon_vma_name usage code
  selftests/vm: cleanup hugetlb file after mremap test

Pull s390 fixes from Vasily Gorbik:

 - Fix HAVE_DYNAMIC_FTRACE_WITH_ARGS implementation by providing correct
   switching between ftrace_caller/ftrace_regs_caller and supplying
   pt_regs only when ftrace_regs_caller is activated.

 - Fix exception table sorting.

 - Fix breakage of kdump tooling by preserving metadata it cannot
   function without.

* tag 's390-5.17-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/extable: fix exception table sorting
  s390/ftrace: fix arch_ftrace_get_regs implementation
  s390/ftrace: fix ftrace_caller/ftrace_regs_caller generation
  s390/setup: preserve memory at OLDMEM_BASE and OLDMEM_SIZE

CONFIG_DEBUG_INFO can't be set by user directly, so set
CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y instead.

Otherwise, we end up with no debuginfo in vmlinux which is a big no-no
for kernel debugging.

Link: https://lkml.kernel.org/r/20220301202920.18488-1-quic_qiancai@quicinc.comSigned-off-by: Qian Cai <quic_qiancai@quicinc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Since bit 57 was exported for uffd-wp write-protected (commit
fb8e37f3: "mm/pagemap: export uffd-wp protection information"),
fixing it can reduce some unnecessary confusion.

Link: https://lkml.kernel.org/r/20220301044538.3042713-1-yun.zhou@windriver.com
Fixes: fb8e37f3 ("mm/pagemap: export uffd-wp protection information")
Signed-off-by: Yun Zhou <yun.zhou@windriver.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Tiberiu A Georgescu <tiberiu.georgescu@nutanix.com>
Cc: Florian Schmidt <florian.schmidt@nutanix.com>
Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Colin Cross <ccross@google.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The error message when I build vm tests on debian10 (GLIBC 2.28):

    userfaultfd.c: In function `userfaultfd_pagemap_test':
    userfaultfd.c:1393:37: error: `MADV_PAGEOUT' undeclared (first use
    in this function); did you mean `MADV_RANDOM'?
      if (madvise(area_dst, test_pgsize, MADV_PAGEOUT))
                                         ^~~~~~~~~~~~
                                         MADV_RANDOM

This patch includes these newer definitions from UAPI linux/mman.h, is
useful to fix tests build on systems without these definitions in glibc
sys/mman.h.

Link: https://lkml.kernel.org/r/20220227055330.43087-2-zhouchengming@bytedance.comSigned-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Wangyong reports: after enabling tmpfs filesystem to support transparent
hugepage with the following command:

  echo always > /sys/kernel/mm/transparent_hugepage/shmem_enabled

the docker program tries to add F_SEAL_WRITE through the following
command, but it fails unexpectedly with errno EBUSY:

  fcntl(5, F_ADD_SEALS, F_SEAL_WRITE) = -1.

That is because memfd_tag_pins() and memfd_wait_for_pins() were never
updated for shmem huge pages: checking page_mapcount() against
page_count() is hopeless on THP subpages - they need to check
total_mapcount() against page_count() on THP heads only.

Make memfd_tag_pins() (compared > 1) as strict as memfd_wait_for_pins()
(compared != 1): either can be justified, but given the non-atomic
total_mapcount() calculation, it is better now to be strict.  Bear in
mind that total_mapcount() itself scans all of the THP subpages, when
choosing to take an XA_CHECK_SCHED latency break.

Also fix the unlikely xa_is_value() case in memfd_wait_for_pins(): if a
page has been swapped out since memfd_tag_pins(), then its refcount must
have fallen, and so it can safely be untagged.

Link: https://lkml.kernel.org/r/a4f79248-df75-2c8c-3df-ba3317ccb5da@google.comSigned-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Reported-by: wangyong <wang.yong12@zte.com.cn>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: CGEL ZTE <cgel.zte@gmail.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When adjacent vmas are being merged it can result in the vma that was
originally passed to madvise_update_vma being destroyed.  In the current
implementation, the name parameter passed to madvise_update_vma points
directly to vma->anon_name and it is used after the call to vma_merge.
In the cases when vma_merge merges the original vma and destroys it,
this might result in UAF.  For that the original vma would have to hold
the anon_vma_name with the last reference.  The following vma would need
to contain a different anon_vma_name object with the same string.  Such
scenario is shown below:

madvise_vma_behavior(vma)
  madvise_update_vma(vma, ..., anon_name == vma->anon_name)
    vma_merge(vma)
      __vma_adjust(vma) <-- merges vma with adjacent one
        vm_area_free(vma) <-- frees the original vma
    replace_vma_anon_name(anon_name) <-- UAF of vma->anon_name

Fix this by raising the name refcount and stabilizing it.

Link: https://lkml.kernel.org/r/20220224231834.1481408-3-surenb@google.com
Link: https://lkml.kernel.org/r/20220223153613.835563-3-surenb@google.com
Fixes: 9a10064f ("mm: add a field to store names for private anonymous memory")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: syzbot+aa7b3d4b35f9dc46a366@syzkaller.appspotmail.com
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Gladkov <legion@kernel.org>
Cc: Chris Hyser <chris.hyser@oracle.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Colin Cross <ccross@google.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xiaofeng Cao <caoxiaofeng@yulong.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A deep process chain with many vmas could grow really high.  With
default sysctl_max_map_count (64k) and default pid_max (32k) the max
number of vmas in the system is 2147450880 and the refcounter has
headroom of 1073774592 before it reaches REFCOUNT_SATURATED
(3221225472).

Therefore it's unlikely that an anonymous name refcounter will overflow
with these defaults.  Currently the max for pid_max is PID_MAX_LIMIT
(4194304) and for sysctl_max_map_count it's INT_MAX (2147483647).  In
this configuration anon_vma_name refcount overflow becomes theoretically
possible (that still require heavy sharing of that anon_vma_name between
processes).

kref refcounting interface used in anon_vma_name structure will detect a
counter overflow when it reaches REFCOUNT_SATURATED value but will only
generate a warning and freeze the ref counter.  This would lead to the
refcounted object never being freed.  A determined attacker could leak
memory like that but it would be rather expensive and inefficient way to
do so.

To ensure anon_vma_name refcount does not overflow, stop anon_vma_name
sharing when the refcount reaches REFCOUNT_MAX (2147483647), which still
leaves INT_MAX/2 (1073741823) values before the counter reaches
REFCOUNT_SATURATED.  This should provide enough headroom for raising the
refcounts temporarily.

Link: https://lkml.kernel.org/r/20220223153613.835563-2-surenb@google.comSigned-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Gladkov <legion@kernel.org>
Cc: Chris Hyser <chris.hyser@oracle.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Colin Cross <ccross@google.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xiaofeng Cao <caoxiaofeng@yulong.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Avoid mixing strings and their anon_vma_name referenced pointers by
using struct anon_vma_name whenever possible.  This simplifies the code
and allows easier sharing of anon_vma_name structures when they
represent the same name.

[surenb@google.com: fix comment]

Link: https://lkml.kernel.org/r/20220223153613.835563-1-surenb@google.com
Link: https://lkml.kernel.org/r/20220224231834.1481408-1-surenb@google.comSigned-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Colin Cross <ccross@google.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Alexey Gladkov <legion@kernel.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Chris Hyser <chris.hyser@oracle.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Xiaofeng Cao <caoxiaofeng@yulong.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The hugepage-mremap test will create a file in a hugetlb filesystem.  In
a default 'run_vmtests' run, the file will contain all the hugetlb
pages.  After the test, the file remains and there are no free hugetlb
pages for subsequent tests.  This causes those hugetlb tests to fail.

Change hugepage-mremap to take the name of the hugetlb file as an
argument.  Unlink the file within the test, and just to be sure remove
the file in the run_vmtests script.

Link: https://lkml.kernel.org/r/20220201033459.156944-1-mike.kravetz@oracle.comSigned-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Workaround the Spectre BHB issues for Cortex-A15, Cortex-A57,
Cortex-A72, Cortex-A73 and Cortex-A75. We also include Brahma B15 as
well to be safe, which is affected by Spectre V2 in the same ways as
Cortex-A15.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Use the linker's LOADADDR() macro to get the load address of the
sections, and provide a macro to set the start and end symbols.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Provide a couple of helpers to copy the vectors and stubs, and also
to flush the copied vectors and stubs.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

As per other architectures, add support for reporting the Spectre
vulnerability status via sysfs CPU.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

The following build failure occurs when CONFIG_PPC_64S_HASH_MMU is not
set:

    arch/powerpc/kernel/setup_64.c: In function ‘setup_per_cpu_areas’:
    arch/powerpc/kernel/setup_64.c:811:21: error: ‘mmu_linear_psize’ undeclared (first use in this function); did you mean ‘mmu_virtual_psize’?
      811 |                 if (mmu_linear_psize == MMU_PAGE_4K)
          |                     ^~~~~~~~~~~~~~~~
          |                     mmu_virtual_psize
    arch/powerpc/kernel/setup_64.c:811:21: note: each undeclared identifier is reported only once for each function it appears in

Move the declaration of mmu_linear_psize outside of
CONFIG_PPC_64S_HASH_MMU ifdef.

After the above is fixed, it fails later with the following error:

    ld: arch/powerpc/kexec/file_load_64.o: in function `.arch_kexec_kernel_image_probe':
    file_load_64.c:(.text+0x1c1c): undefined reference to `.add_htab_mem_range'

Fix that, too, by conditioning add_htab_mem_range() symbol to
CONFIG_PPC_64S_HASH_MMU.

Fixes: 387e220a ("powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU")
Reported-by: Erhard F. <erhard_f@mailbox.org>
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215567
Link: https://lore.kernel.org/r/20220301204743.45133-1-muriloo@linux.ibm.com

The commit

   44a3918c ("x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting")

added a warning for the "eIBRS + unprivileged eBPF" combination, which
has been shown to be vulnerable against Spectre v2 BHB-based attacks.

However, there's no warning about the "eIBRS + LFENCE retpoline +
unprivileged eBPF" combo. The LFENCE adds more protection by shortening
the speculation window after a mispredicted branch. That makes an attack
significantly more difficult, even with unprivileged eBPF. So at least
for now the logic doesn't warn about that combination.

But if you then add SMT into the mix, the SMT attack angle weakens the
effectiveness of the LFENCE considerably.

So extend the "eIBRS + unprivileged eBPF" warning to also include the
"eIBRS + LFENCE + unprivileged eBPF + SMT" case.

  [ bp: Massage commit message. ]
Suggested-by: Alyssa Milburn <alyssa.milburn@linux.intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>

With:

  f8a66d60 ("x86,bugs: Unconditionally allow spectre_v2=retpoline,amd")

it became possible to enable the LFENCE "retpoline" on Intel. However,
Intel doesn't recommend it, as it has some weaknesses compared to
retpoline.

Now AMD doesn't recommend it either.

It can still be left available as a cmdline option. It's faster than
retpoline but is weaker in certain scenarios -- particularly SMT, but
even non-SMT may be vulnerable in some cases.

So just unconditionally warn if the user requests it on the cmdline.

  [ bp: Massage commit message. ]
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>