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  1. Mar 10, 2022
  3. Mar 09, 2022
  5. Mar 08, 2022
    • Russell King (Oracle)'s avatar
      ARM: include unprivileged BPF status in Spectre V2 reporting · 25875aa7
      Russell King (Oracle) authored 
      

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: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
      25875aa7
    • Catalin Marinas's avatar
      arm64: Ensure execute-only permissions are not allowed without EPAN · 6e2edd63
      Catalin Marinas authored 
      Commit 18107f8a

 ("arm64: Support execute-only permissions with
Enhanced PAN") re-introduced execute-only permissions when EPAN is
available. When EPAN is not available, arch_filter_pgprot() is supposed
to change a PAGE_EXECONLY permission into PAGE_READONLY_EXEC. However,
if BTI or MTE are present, such check does not detect the execute-only
pgprot in the presence of PTE_GP (BTI) or MT_NORMAL_TAGGED (MTE),
allowing the user to request PROT_EXEC with PROT_BTI or PROT_MTE.

Remove the arch_filter_pgprot() function, change the default VM_EXEC
permissions to PAGE_READONLY_EXEC and update the protection_map[] array
at core_initcall() if EPAN is detected.

Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Fixes: 18107f8a

 ("arm64: Support execute-only permissions with Enhanced PAN")
Cc: <stable@vger.kernel.org> # 5.13.x
Acked-by: default avatarWill Deacon <will@kernel.org>
Reviewed-by: default avatarVladimir Murzin <vladimir.murzin@arm.com>
Tested-by: default avatarVladimir Murzin <vladimir.murzin@arm.com>
      6e2edd63
    • Andy Shevchenko's avatar
      gpio: sim: Declare gpio_sim_hog_config_item_ops static · a9a5b720
      Andy Shevchenko authored 
      Compiler is not happy:

  warning: symbol 'gpio_sim_hog_config_item_ops' was not declared. Should it be static?

Fixes: cb8c474e

 ("gpio: sim: new testing module")
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarBartosz Golaszewski <brgl@bgdev.pl>
      a9a5b720
    • Linus Torvalds's avatar
      Merge tag 'x86_bugs_for_v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 4a01e748
      Linus Torvalds authored 
      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
      4a01e748
    • Linus Torvalds's avatar
      Merge tag 'mtd/fixes-for-5.17-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux · ea4424be
      Linus Torvalds authored 
      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
      ea4424be
    • Linus Torvalds's avatar
      Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost · 06be3029
      Linus Torvalds authored 
      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
      06be3029
    • Halil Pasic's avatar
      swiotlb: rework "fix info leak with DMA_FROM_DEVICE" · aa6f8dcb
      Halil Pasic authored 
      

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: default avatarHalil Pasic <pasic@linux.ibm.com>
Fixes: ddbd89de

 ("swiotlb: fix info leak with DMA_FROM_DEVICE")
Cc: stable@vger.kernel.org
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      aa6f8dcb
    • James Morse's avatar
      arm64: proton-pack: Include unprivileged eBPF status in Spectre v2 mitigation reporting · 58c9a506
      James Morse authored 
      

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: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarJames Morse <james.morse@arm.com>
      58c9a506
    • Roger Quadros's avatar
      mtd: rawnand: omap2: Actually prevent invalid configuration and build error · 42da5a4b
      Roger Quadros authored 
      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: default avatarRoger Quadros <rogerq@kernel.org>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Tested-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/linux-mtd/20220219193600.24892-1-rogerq@kernel.org
      42da5a4b
  7. Mar 07, 2022