Commit Graph

901814 Commits

Author SHA1 Message Date
Nikolai Merinov
d5528d5e91 partitions/efi: Fix partition name parsing in GUID partition entry
GUID partition entry defined to have a partition name as 36 UTF-16LE
code units. This means that on big-endian platforms ASCII symbols
would be read with 0xXX00 efi_char16_t character code. In order to
correctly extract ASCII characters from a partition name field we
should be converted from 16LE to CPU architecture.

The problem exists on all big endian platforms.

[ mingo: Minor edits. ]

Fixes: eec7ecfede ("genhd, efi: add efi partition metadata to hd_structs")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nikolai Merinov <n.merinov@inango-systems.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200308080859.21568-29-ardb@kernel.org
Link: https://lore.kernel.org/r/797777312.1324734.1582544319435.JavaMail.zimbra@inango-systems.com/
2020-03-08 10:00:09 +01:00
Arvind Sankar
0347d8c28c efi/x86: Fix cast of image argument
handle_protocol() expects void **, not void *.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200305143642.820865-1-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-28-ardb@kernel.org
2020-03-08 10:00:08 +01:00
Ard Biesheuvel
ac82d35699 efi/libstub/x86: Use ULONG_MAX as upper bound for all allocations
The header flag XLF_CAN_BE_LOADED_ABOVE_4G will inform us whether
allocations above 4 GiB for kernel, command line, etc are permitted,
so we take it into account when calling efi_allocate_pages() etc.

However, CONFIG_EFI_STUB implies CONFIG_RELOCATABLE, and so the flag
is guaranteed to be set on x86_64 builds, whereas i386 builds are
guaranteed to run under firmware that will not allocate above 4 GB
in the first place.

So drop the check, and just pass ULONG_MAX as the upper bound for
all allocations.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200303225054.28741-1-ardb@kernel.org
Link: https://lore.kernel.org/r/20200308080859.21568-27-ardb@kernel.org
2020-03-08 10:00:07 +01:00
Vladis Dronov
8d8ab66a71 efi: Fix a mistype in comments mentioning efivar_entry_iter_begin()
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200305084041.24053-4-vdronov@redhat.com
Link: https://lore.kernel.org/r/20200308080859.21568-26-ardb@kernel.org
2020-03-08 10:00:07 +01:00
Masahiro Yamada
2fb2c17993 efi/libstub: Avoid linking libstub/lib-ksyms.o into vmlinux
drivers/firmware/efi/libstub/Makefile builds a static library, which
is not linked into the main vmlinux target in the ordinary way [arm64],
or at all [ARM, x86].

Since commit:

  7f2084fa55 ("[kbuild] handle exports in lib-y objects reliably")

any Makefile using lib-y generates lib-ksyms.o which is linked into vmlinux.

In this case, the following garbage object is linked into vmlinux.

  drivers/firmware/efi/libstub/lib-ksyms.o

We do not want to follow the default linking rules for static libraries
built under libstub/ so using subdir-y instead of obj-y is the correct
way to descend into this directory.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
[ardb: update commit log to clarify that arm64 deviates in this respect]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200305055047.6097-1-masahiroy@kernel.org
Link: https://lore.kernel.org/r/20200308080859.21568-23-ardb@kernel.org
2020-03-08 10:00:06 +01:00
Ard Biesheuvel
57648adb31 efi/x86: Preserve %ebx correctly in efi_set_virtual_address_map()
Commit:

  59f2a619a2 ("efi: Add 'runtime' pointer to struct efi")

modified the assembler routine called by efi_set_virtual_address_map(),
to grab the 'runtime' EFI service pointer while running with paging
disabled (which is tricky to do in C code)

After the change, register %ebx is not restored correctly, resulting
in all kinds of weird behavior, so fix that.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200304133515.15035-1-ardb@kernel.org
Link: https://lore.kernel.org/r/20200308080859.21568-22-ardb@kernel.org
2020-03-08 09:58:23 +01:00
Ard Biesheuvel
dd09fad9d2 efi/x86: Ignore the memory attributes table on i386
Commit:

  3a6b6c6fb2 ("efi: Make EFI_MEMORY_ATTRIBUTES_TABLE initialization common across all architectures")

moved the call to efi_memattr_init() from ARM specific to the generic
EFI init code, in order to be able to apply the restricted permissions
described in that table on x86 as well.

We never enabled this feature fully on i386, and so mapping and
reserving this table is pointless. However, due to the early call to
memblock_reserve(), the memory bookkeeping gets confused to the point
where it produces the splat below when we try to map the memory later
on:

  ------------[ cut here ]------------
  ioremap on RAM at 0x3f251000 - 0x3fa1afff
  WARNING: CPU: 0 PID: 0 at arch/x86/mm/ioremap.c:166 __ioremap_caller ...
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.20.0 #48
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
  EIP: __ioremap_caller.constprop.0+0x249/0x260
  Code: 90 0f b7 05 4e 38 40 de 09 45 e0 e9 09 ff ff ff 90 8d 45 ec c6 05 ...
  EAX: 00000029 EBX: 00000000 ECX: de59c228 EDX: 00000001
  ESI: 3f250fff EDI: 00000000 EBP: de3edf20 ESP: de3edee0
  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00200296
  CR0: 80050033 CR2: ffd17000 CR3: 1e58c000 CR4: 00040690
  Call Trace:
   ioremap_cache+0xd/0x10
   ? old_map_region+0x72/0x9d
   old_map_region+0x72/0x9d
   efi_map_region+0x8/0xa
   efi_enter_virtual_mode+0x260/0x43b
   start_kernel+0x329/0x3aa
   i386_start_kernel+0xa7/0xab
   startup_32_smp+0x164/0x168
  ---[ end trace e15ccf6b9f356833 ]---

Let's work around this by disregarding the memory attributes table
altogether on i386, which does not result in a loss of functionality
or protection, given that we never consumed the contents.

Fixes: 3a6b6c6fb2 ("efi: Make EFI_MEMORY_ATTRIBUTES_TABLE ... ")
Tested-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200304165917.5893-1-ardb@kernel.org
Link: https://lore.kernel.org/r/20200308080859.21568-21-ardb@kernel.org
2020-03-08 09:58:23 +01:00
Arvind Sankar
d5cdf4cfea efi/x86: Don't relocate the kernel unless necessary
Add alignment slack to the PE image size, so that we can realign the
decompression buffer within the space allocated for the image.

Only relocate the kernel if it has been loaded at an unsuitable address:

 - Below LOAD_PHYSICAL_ADDR, or
 - Above 64T for 64-bit and 512MiB for 32-bit

For 32-bit, the upper limit is conservative, but the exact limit can be
difficult to calculate.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200303221205.4048668-6-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-20-ardb@kernel.org
2020-03-08 09:58:22 +01:00
Arvind Sankar
964124a97b efi/x86: Remove extra headroom for setup block
The following commit:

  223e3ee56f ("efi/x86: add headroom to decompressor BSS to account for setup block")

added headroom to the PE image to account for the setup block, which
wasn't used for the decompression buffer.

Now that the decompression buffer is located at the start of the image,
and includes the setup block, this is no longer required.

Add a check to make sure that the head section of the compressed kernel
won't overwrite itself while relocating. This is only for
future-proofing as with current limits on the setup and the actual size
of the head section, this can never happen.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200303221205.4048668-5-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-19-ardb@kernel.org
2020-03-08 09:58:21 +01:00
Arvind Sankar
26725192c4 efi/x86: Add kernel preferred address to PE header
Store the kernel's link address as ImageBase in the PE header. Note that
the PE specification requires the ImageBase to be 64k aligned. The
preferred address should almost always satisfy that, except for 32-bit
kernel if the configuration has been customized.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200303221205.4048668-4-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-18-ardb@kernel.org
2020-03-08 09:58:20 +01:00
Arvind Sankar
1887c9b653 efi/x86: Decompress at start of PE image load address
When booted via PE loader, define image_offset to hold the offset of
startup_32() from the start of the PE image, and use it as the start of
the decompression buffer.

[ mingo: Fixed the grammar in the comments. ]

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200303221205.4048668-3-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-17-ardb@kernel.org
2020-03-08 09:58:19 +01:00
Arvind Sankar
8ef44be393 x86/boot/compressed/32: Save the output address instead of recalculating it
In preparation for being able to decompress into a buffer starting at a
different address than startup_32, save the calculated output address
instead of recalculating it later.

We now keep track of three addresses:

	%edx: startup_32 as we were loaded by bootloader
	%ebx: new location of compressed kernel
	%ebp: start of decompression buffer

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200303221205.4048668-2-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-16-ardb@kernel.org
2020-03-08 09:58:19 +01:00
Ard Biesheuvel
f3fa0efce2 efi/libstub/x86: Deal with exit() boot service returning
Even though it is uncommon, there are cases where the Exit() EFI boot
service might return, e.g., when we were booted via the EFI handover
protocol from OVMF and the kernel image was specified on the command
line, in which case Exit() attempts to terminate the boot manager,
which is not an EFI application itself.

So let's drop into an infinite loop instead of randomly executing code
that isn't expecting it.

Tested-by: Nathan Chancellor <natechancellor@gmail.com> # build
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
[ardb: put 'hlt' in deadloop]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200303080648.21427-1-ardb@kernel.org
Link: https://lore.kernel.org/r/20200308080859.21568-15-ardb@kernel.org
2020-03-08 09:58:18 +01:00
Arvind Sankar
81a34892c2 x86/boot: Use unsigned comparison for addresses
The load address is compared with LOAD_PHYSICAL_ADDR using a signed
comparison currently (using jge instruction).

When loading a 64-bit kernel using the new efi32_pe_entry() point added by:

  97aa276579 ("efi/x86: Add true mixed mode entry point into .compat section")

using Qemu with -m 3072, the firmware actually loads us above 2Gb,
resulting in a very early crash.

Use the JAE instruction to perform a unsigned comparison instead, as physical
addresses should be considered unsigned.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200301230436.2246909-6-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-14-ardb@kernel.org
2020-03-08 09:58:17 +01:00
Arvind Sankar
8acf63efa1 efi/x86: Avoid using code32_start
code32_start is meant for 16-bit real-mode bootloaders to inform the
kernel where the 32-bit protected mode code starts. Nothing in the
protected mode kernel except the EFI stub uses it.

efi_main() currently returns boot_params, with code32_start set inside it
to tell efi_stub_entry() where startup_32 is located. Since it was invoked
by efi_stub_entry() in the first place, boot_params is already known.
Return the address of startup_32 instead.

This will allow a 64-bit kernel to live above 4Gb, for example, and it's
cleaner as well.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200301230436.2246909-5-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-13-ardb@kernel.org
2020-03-08 09:58:17 +01:00
Arvind Sankar
3fab43318f efi/x86: Make efi32_pe_entry() more readable
Set up a proper frame pointer in efi32_pe_entry() so that it's easier to
calculate offsets for arguments.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200301230436.2246909-4-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-12-ardb@kernel.org
2020-03-08 09:58:16 +01:00
Arvind Sankar
71ff44ac6c efi/x86: Respect 32-bit ABI in efi32_pe_entry()
verify_cpu() clobbers BX and DI. In case we have to return error, we need
to preserve them to respect the 32-bit calling convention.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200301230436.2246909-3-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-11-ardb@kernel.org
2020-03-08 09:58:15 +01:00
Arvind Sankar
3cdcd6899e efi/x86: Annotate the LOADED_IMAGE_PROTOCOL_GUID with SYM_DATA
Use SYM_DATA*() macros to annotate this constant, and explicitly align it
to 4-byte boundary. Use lower-case for hexadecimal data.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200301230436.2246909-2-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-10-ardb@kernel.org
2020-03-08 09:58:14 +01:00
Heinrich Schuchardt
f9834f18f0 efi/libstub: Add libstub/mem.c to the documentation tree
Let the description of the efi/libstub/mem.c functions appear in the kernel
API documentation in the following chapters:

    The Linux driver implementer’s API guide
        Linux Firmware API
            UEFI Support
                UEFI stub library functions

Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200221035832.144960-1-xypron.glpk@gmx.de
Link: https://lore.kernel.org/r/20200308080859.21568-9-ardb@kernel.org
2020-03-08 09:58:13 +01:00
Lukas Bulwahn
73f2f56366 MAINTAINERS: Adjust EFI entry to removing eboot.c
Commit:

  c2d0b47015 ("efi/libstub/x86: Incorporate eboot.c into libstub")

removed arch/x86/boot/compressed/eboot.[ch], but missed to adjust the
MAINTAINERS entry.

Since then, ./scripts/get_maintainer.pl --self-test complains:

  warning: no file matches F: arch/x86/boot/compressed/eboot.[ch]

Rectify EXTENSIBLE FIRMWARE INTERFACE (EFI) entry in MAINTAINERS.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200301155748.4788-1-lukas.bulwahn@gmail.com
Link: https://lore.kernel.org/r/20200308080859.21568-8-ardb@kernel.org
2020-03-08 09:58:12 +01:00
Ingo Molnar
6120681bdf Merge branch 'efi/urgent' into efi/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-08 09:57:58 +01:00
Vladis Dronov
d6c066fda9 efi: Add a sanity check to efivar_store_raw()
Add a sanity check to efivar_store_raw() the same way
efivar_{attr,size,data}_read() and efivar_show_raw() have it.

Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200305084041.24053-3-vdronov@redhat.com
Link: https://lore.kernel.org/r/20200308080859.21568-25-ardb@kernel.org
2020-03-08 09:56:48 +01:00
Vladis Dronov
286d3250c9 efi: Fix a race and a buffer overflow while reading efivars via sysfs
There is a race and a buffer overflow corrupting a kernel memory while
reading an EFI variable with a size more than 1024 bytes via the older
sysfs method. This happens because accessing struct efi_variable in
efivar_{attr,size,data}_read() and friends is not protected from
a concurrent access leading to a kernel memory corruption and, at best,
to a crash. The race scenario is the following:

CPU0:                                CPU1:
efivar_attr_read()
  var->DataSize = 1024;
  efivar_entry_get(... &var->DataSize)
    down_interruptible(&efivars_lock)
                                     efivar_attr_read() // same EFI var
                                       var->DataSize = 1024;
                                       efivar_entry_get(... &var->DataSize)
                                         down_interruptible(&efivars_lock)
    virt_efi_get_variable()
    // returns EFI_BUFFER_TOO_SMALL but
    // var->DataSize is set to a real
    // var size more than 1024 bytes
    up(&efivars_lock)
                                         virt_efi_get_variable()
                                         // called with var->DataSize set
                                         // to a real var size, returns
                                         // successfully and overwrites
                                         // a 1024-bytes kernel buffer
                                         up(&efivars_lock)

This can be reproduced by concurrent reading of an EFI variable which size
is more than 1024 bytes:

  ts# for cpu in $(seq 0 $(nproc --ignore=1)); do ( taskset -c $cpu \
  cat /sys/firmware/efi/vars/KEKDefault*/size & ) ; done

Fix this by using a local variable for a var's data buffer size so it
does not get overwritten.

Fixes: e14ab23dde ("efivars: efivar_entry API")
Reported-by: Bob Sanders <bob.sanders@hpe.com> and the LTP testsuite
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200305084041.24053-2-vdronov@redhat.com
Link: https://lore.kernel.org/r/20200308080859.21568-24-ardb@kernel.org
2020-03-08 09:56:34 +01:00
Ingo Molnar
3be5f0d286 Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core
More EFI updates for v5.7

 - Incorporate a stable branch with the EFI pieces of Hans's work on
   loading device firmware from EFI boot service memory regions

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-08 09:23:36 +01:00
Linus Torvalds
61a09258f2 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull rdma fixes from Jason Gunthorpe:
 "Nothing particularly exciting, some small ODP regressions from the mmu
  notifier rework, another bunch of syzkaller fixes, and a bug fix for a
  botched syzkaller fix in the first rc pull request.

   - Fix busted syzkaller fix in 'get_new_pps' - this turned out to
     crash on certain HW configurations

   - Bug fixes for various missed things in error unwinds

   - Add a missing rcu_read_lock annotation in hfi/qib

   - Fix two ODP related regressions from the recent mmu notifier
     changes

   - Several more syzkaller bugs in siw, RDMA netlink, verbs and iwcm

   - Revert an old patch in CMA as it is now shown to not be allocating
     port numbers properly"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  RDMA/iwcm: Fix iwcm work deallocation
  RDMA/siw: Fix failure handling during device creation
  RDMA/nldev: Fix crash when set a QP to a new counter but QPN is missing
  RDMA/odp: Ensure the mm is still alive before creating an implicit child
  RDMA/core: Fix protection fault in ib_mr_pool_destroy
  IB/mlx5: Fix implicit ODP race
  IB/hfi1, qib: Ensure RCU is locked when accessing list
  RDMA/core: Fix pkey and port assignment in get_new_pps
  RMDA/cm: Fix missing ib_cm_destroy_id() in ib_cm_insert_listen()
  RDMA/rw: Fix error flow during RDMA context initialization
  RDMA/core: Fix use of logical OR in get_new_pps
  Revert "RDMA/cma: Simplify rdma_resolve_addr() error flow"
2020-03-07 19:52:55 -06:00
Linus Torvalds
c200376527 Merge tag 'io_uring-5.6-2020-03-07' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe:
 "Here are a few io_uring fixes that should go into this release. This
  contains:

   - Removal of (now) unused io_wq_flush() and associated flag (Pavel)

   - Fix cancelation lockup with linked timeouts (Pavel)

   - Fix for potential use-after-free when freeing percpu ref for fixed
     file sets

   - io-wq cancelation fixups (Pavel)"

* tag 'io_uring-5.6-2020-03-07' of git://git.kernel.dk/linux-block:
  io_uring: fix lockup with timeouts
  io_uring: free fixed_file_data after RCU grace period
  io-wq: remove io_wq_flush and IO_WQ_WORK_INTERNAL
  io-wq: fix IO_WQ_WORK_NO_CANCEL cancellation
2020-03-07 14:20:29 -06:00
Linus Torvalds
5dfcc13902 Merge tag 'block-5.6-2020-03-07' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
 "Here are a few fixes that should go into this release. This contains:

   - Revert of a bad bcache patch from this merge window

   - Removed unused function (Daniel)

   - Fixup for the blktrace fix from Jan from this release (Cengiz)

   - Fix of deeper level bfqq overwrite in BFQ (Carlo)"

* tag 'block-5.6-2020-03-07' of git://git.kernel.dk/linux-block:
  block, bfq: fix overwrite of bfq_group pointer in bfq_find_set_group()
  blktrace: fix dereference after null check
  Revert "bcache: ignore pending signals when creating gc and allocator thread"
  block: Remove used kblockd_schedule_work_on()
2020-03-07 14:14:38 -06:00
Linus Torvalds
6f784a3179 Merge tag 'media/v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media fixes from Mauro Carvalho Chehab:

 - a fix for the media controller links in both hantro driver and in
   v4l2-mem2mem core

 - some fixes for the pulse8-cec driver

 - vicodec: handle alpha channel for RGB32 formats, as it may be used

 - mc-entity.c: fix handling of pad flags

* tag 'media/v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  media: hantro: Fix broken media controller links
  media: mc-entity.c: use & to check pad flags, not ==
  media: v4l2-mem2mem.c: fix broken links
  media: vicodec: process all 4 components for RGB32 formats
  media: pulse8-cec: close serio in disconnect, not adap_free
  media: pulse8-cec: INIT_DELAYED_WORK was called too late
2020-03-07 12:00:13 -06:00
Pavel Begunkov
f0e20b8943 io_uring: fix lockup with timeouts
There is a recipe to deadlock the kernel: submit a timeout sqe with a
linked_timeout (e.g.  test_single_link_timeout_ception() from liburing),
and SIGKILL the process.

Then, io_kill_timeouts() takes @ctx->completion_lock, but the timeout
isn't flagged with REQ_F_COMP_LOCKED, and will try to double grab it
during io_put_free() to cancel the linked timeout. Probably, the same
can happen with another io_kill_timeout() call site, that is
io_commit_cqring().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-07 08:35:56 -07:00
Linus Torvalds
9d588f6360 Merge tag 's390-5.6-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Vasily Gorbik:

 - Fix panic in gup_fast on large pud by providing an implementation of
   pud_write. This has been overlooked during migration to common gup
   code.

 - Fix unexpected write combining on PCI stores.

* tag 's390-5.6-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/pci: Fix unexpected write combine on resource
  s390/mm: fix panic in gup_fast on large pud
2020-03-07 08:12:47 -06:00
Linus Torvalds
5236647adb Merge tag 'powerpc-5.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
 "Some more powerpc fixes for 5.6:

   - One fix for a recent regression to our breakpoint/watchpoint code.

   - Another fix for our KUAP support, this time a missing annotation in
     a rarely used path in signal handling.

   - A fix for our handling of a CPU feature that effects the PMU, when
     booting guests in some configurations.

   - A minor fix to our linker script to explicitly include the .BTF
     section.

  Thanks to: Christophe Leroy, Desnes A. Nunes do Rosario, Leonardo
  Bras, Naveen N. Rao, Ravi Bangoria, Stefan Berger"

* tag 'powerpc-5.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm: Fix missing KUAP disable in flush_coherent_icache()
  powerpc: fix hardware PMU exception bug on PowerVM compatibility mode systems
  powerpc: Include .BTF section
  powerpc/watchpoint: Don't call dar_within_range() for Book3S
2020-03-07 08:10:34 -06:00
Linus Torvalds
cbee7c8b44 Merge tag 'for-linus-5.6b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
 "Four fixes and a small cleanup patch:

   - two fixes by Dongli Zhang fixing races in the xenbus driver

   - two fixes by me fixing issues introduced in 5.6

   - a small cleanup by Gustavo Silva replacing a zero-length array with
     a flexible-array"

* tag 'for-linus-5.6b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/blkfront: fix ring info addressing
  xen/xenbus: fix locking
  xenbus: req->err should be updated before req->state
  xenbus: req->body should be updated before req->state
  xen: Replace zero-length array with flexible-array member
2020-03-07 08:04:54 -06:00
Linus Torvalds
fa883d6afb Merge tag 'for-linus-2020-03-07' of gitolite.kernel.org:pub/scm/linux/kernel/git/brauner/linux
Pull thread fixes from Christian Brauner:
 "Here are a few hopefully uncontroversial fixes:

   - Use RCU_INIT_POINTER() when initializing rcu protected members in
     task_struct to fix sparse warnings.

   - Add pidfd_fdinfo_test binary to .gitignore file"

* tag 'for-linus-2020-03-07' of gitolite.kernel.org:pub/scm/linux/kernel/git/brauner/linux:
  selftests: pidfd: Add pidfd_fdinfo_test in .gitignore
  exit: Fix Sparse errors and warnings
  fork: Use RCU_INIT_POINTER() instead of rcu_access_pointer()
2020-03-07 08:01:43 -06:00
Linus Torvalds
676fc8de31 Merge tag 'sound-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
 "The regular "bump-in-the-middle" updates, containing mostly ASoC-
  related fixes at this time. All changes are reasonably small.

  A few entries are for ASoC and ALSA core parts (DAPM, PCM, topology)
  for followups of the recent changes and potential buffer overflow by
  snprintf(), while the rest are (both new and old) device-specific
  fixes for Intel, meson, tas2562, rt1015, as well as the usual HD-audio
  quirks"

* tag 'sound-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (25 commits)
  ALSA: sgio2audio: Remove usage of dropped hw_params/hw_free functions
  ALSA: hda/realtek - Enable the headset of ASUS B9450FA with ALC294
  ALSA: hda/realtek - Fix silent output on Gigabyte X570 Aorus Master
  ALSA: hda/realtek - Add Headset Button supported for ThinkPad X1
  ALSA: hda/realtek - Add Headset Mic supported
  ASoC: wm8741: Fix typo in Kconfig prompt
  ASoC: stm32: sai: manage rebind issue
  ASoC: SOF: Fix snd_sof_ipc_stream_posn()
  ASoC: rt1015: modify pre-divider for sysclk
  ASoC: rt1015: add operation callback function for rt1015_dai[]
  ASoC: soc-component: tidyup snd_soc_pcm_component_sync_stop()
  ASoC: dapm: Correct DAPM handling of active widgets during shutdown
  ASoC: tas2562: Fix sample rate error message
  ASoC: Intel: Skylake: Fix available clock counter incrementation
  ASoC: soc-pcm/soc-compress: don't use snd_soc_dapm_stream_stop()
  ASoC: meson: g12a: add tohdmitx reset
  ASoC: pcm512x: Fix unbalanced regulator enable call in probe error path
  ASoC: soc-core: fix for_rtd_codec_dai_rollback() macro
  ASoC: topology: Fix memleak in soc_tplg_manifest_load()
  ASoC: topology: Fix memleak in soc_tplg_link_elems_load()
  ...
2020-03-07 07:59:30 -06:00
Takashi Iwai
5a56996b0f Merge tag 'asoc-fix-v5.6-rc4' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Fixes for v5.6

More fixes that have arrived since the merge window, spread out all
over.  There's a few things like the operation callback addition for
rt1015 and the meson reset addition which add small new bits of
functionality to fix non-working systems, they're all very small and for
parts of newly added functionality.
2020-03-07 07:24:36 +01:00
Linus Torvalds
63849c8f41 Merge tag 'linux-kselftest-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull kselftest update from Shuah Khan:
 "This consists of a cleanup patch to undo changes to global .gitignore
  that added selftests/lkdtm objects and add them to a local
  selftests/lkdtm/.gitignore.

  Summary of Linus's comments on local vs. global gitignore scope:

   - Keep local gitignore patterns in local files.

   - Put only global gitignore patterns in the top-level gitignore file.

  Local scope keeps things much better separated. It also incidentally
  means that if a directory gets renamed, the gitignore file continues
  to work unless in the case of renaming the actual files themselves
  that are named in the gitignore"

* tag 'linux-kselftest-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftest/lkdtm: Use local .gitignore
2020-03-06 17:03:37 -06:00
Linus Torvalds
7e6582ef32 Merge tag 'riscv-for-linus-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Palmer Dabbelt:
 "This contains a handful of fixes that I would like to target for 5.6:

   - A pair of fixes to module loading, which we hope solve the last of
     the issues with module text being loaded too sparsely for our call
     relocations.

   - A Kconfig fix that disallows selecting memory models not supported
     by NOMMU.

   - A series of Kconfig updates to ease selecting the drivers necessary
     to run on QEMU's virt platform.

   - DTS updates for SiFive's HiFive Unleashed.

   - A fix to our seccomp support that avoids mangling restartable
     syscalls"

* tag 'riscv-for-linus-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: fix seccomp reject syscall code path
  riscv: dts: Add GPIO reboot method to HiFive Unleashed DTS file
  RISC-V: Select Goldfish RTC driver for QEMU virt machine
  RISC-V: Select SYSCON Reboot and Poweroff for QEMU virt machine
  RISC-V: Enable QEMU virt machine support in defconfigs
  RISC-V: Add kconfig option for QEMU virt machine
  riscv: Fix range looking for kernel image memblock
  riscv: Force flat memory model with no-mmu
  riscv: Change code model of module to medany to improve data accessing
  riscv: avoid the PIC offset of static percpu data in module beyond 2G limits
2020-03-06 16:38:33 -06:00
Jonathan Neuschäfer
611d61f9ac parse-maintainers: Mark as executable
This makes the script more convenient to run.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-03-06 16:29:21 -06:00
Linus Torvalds
bdf1ea7ca8 Merge tag 'devicetree-fixes-for-5.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree fixes from Rob Herring:
 "Another batch of DT fixes. I think this should be the last of it, but
  sending pull requests seems to cause people to send more fixes.

  Summary:

   - Fixes for warnings introduced by hierarchical PSCI binding changes

   - Fixes for broken doc references due to DT schema conversions

   - Several grammar and typo fixes

   - Fix a bunch of dtc warnings in examples"

* tag 'devicetree-fixes-for-5.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  dt-bindings: arm: Fixup the DT bindings for hierarchical PSCI states
  dt-bindings: power: Extend nodename pattern for power-domain providers
  MAINTAINERS: update ALLWINNER CPUFREQ DRIVER entry
  dt-bindings: bus: Drop empty compatible string in example
  dt-bindings: power: Convert domain-idle-states bindings to json-schema
  dt-bindings: arm: Fix cpu compatibles in the hierarchical example for PSCI
  dt-bindings: arm: Correct links to idle states definitions
  dt-bindings: mfd: Fix typo in file name of twl-familly.txt
  dt-bindings: mfd: tps65910: Improve grammar
  dt-bindings: mfd: zii,rave-sp: Fix a typo ("onborad")
  dt-bindings: arm: fsl: fix APF6Dev compatible
  dt-bindings: Fix dtc warnings in examples
  docs: dt: fix several broken doc references
  docs: dt: fix several broken references due to renames
  MAINTAINERS: clean up PCIE DRIVER FOR CAVIUM THUNDERX
2020-03-06 16:11:34 -06:00
Linus Torvalds
2f501bb180 Merge tag 'drm-fixes-2020-03-06-1' of git://anongit.freedesktop.org/drm/drm
Pull vgacon fix from Daniel Vetter:
 "One vgacon input check for stable"

* tag 'drm-fixes-2020-03-06-1' of git://anongit.freedesktop.org/drm/drm:
  vgacon: Fix a UAF in vgacon_invert_region
2020-03-06 16:08:48 -06:00
Linus Torvalds
30fe0d07fd Merge tag 'for-5.6-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fix from David Sterba:
 "One fixup for DIO when in use with the new checksums, a missed case
  where the checksum size was still assuming u32"

* tag 'for-5.6-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix RAID direct I/O reads with alternate csums
2020-03-06 14:56:46 -06:00
Linus Torvalds
0b25d45803 Merge tag 'filelock-v5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux
Pull file locking fixes from Jeff Layton:
 "Just a couple of late-breaking patches for the file locking code. The
  second patch (from yangerkun) fixes a rather nasty looking potential
  use-after-free that should go to stable.

  The other patch could technically wait for 5.7, but it's fairly
  innocuous so I figured we might as well take it"

* tag 'filelock-v5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
  locks: fix a potential use-after-free problem when wakeup a waiter
  fcntl: Distribute switch variables for initialization
2020-03-06 14:55:27 -06:00
Linus Torvalds
ae24a21bbd Merge tag 'spi-fix-v5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi fixes from Mark Brown:
 "A selection of small fixes, mostly for drivers, that have arrived
  since the merge window. None of them are earth shattering in
  themselves but all useful for affected systems"

* tag 'spi-fix-v5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: spi_register_controller(): free bus id on error paths
  spi: bcm63xx-hsspi: Really keep pll clk enabled
  spi: atmel-quadspi: fix possible MMIO window size overrun
  spi/zynqmp: remove entry that causes a cs glitch
  spi: pxa2xx: Add CS control clock quirk
  spi: spidev: Fix CS polarity if GPIO descriptors are used
  spi: qup: call spi_qup_pm_resume_runtime before suspending
  spi: spi-omap2-mcspi: Support probe deferral for DMA channels
  spi: spi-omap2-mcspi: Handle DMA size restriction on AM65x
2020-03-06 14:50:16 -06:00
Linus Torvalds
43c63729c9 Merge tag 'regulator-fix-v5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator
Pull regulator fixes from Mark Brown:
 "A couple of small fixes, one for a minor issue in the stm32-vrefbuf
  driver and a documentation fix in the Qualcomm code"

* tag 'regulator-fix-v5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: stm32-vrefbuf: fix a possible overshoot when re-enabling
  regulator: qcom_spmi: Fix docs for PM8004
2020-03-06 14:48:30 -06:00
Linus Torvalds
08e39fcb92 Merge tag 'hwmon-for-v5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon fixes from Guenter Roeck:
 "Fix an error return in the adt7462 driver, bad voltage limits reported
  by the xdpe12284 driver, and a broken documentation reference in the
  adm1177 driver documentation"

* tag 'hwmon-for-v5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (adt7462) Fix an error return in ADT7462_REG_VOLT()
  hwmon: (pmbus/xdpe12284) Add callback for vout limits conversion
  docs: adm1177: fix a broken reference
2020-03-06 14:47:06 -06:00
Linus Torvalds
c20c4a084a Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Will Deacon:
 "Here are another three arm64 fixes for 5.6, all pretty minor. Main
  thing is fixing a silly bug in the fsl_imx8_ddr PMU driver where we
  would zero the counters when disabling them.

   - Fix misreporting of ASID limit when KPTI is enabled

   - Fix busted NULL pointer checks for GICC structure in ACPI PMU code

   - Avoid nobbling the "fsl_imx8_ddr" PMU counters when disabling them"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: context: Fix ASID limit in boot messages
  drivers/perf: arm_pmu_acpi: Fix incorrect checking of gicc pointer
  drivers/perf: fsl_imx8_ddr: Correct the CLEAR bit definition
2020-03-06 14:35:47 -06:00
Zhang Xiaoxu
513dc792d6 vgacon: Fix a UAF in vgacon_invert_region
When syzkaller tests, there is a UAF:
  BUG: KASan: use after free in vgacon_invert_region+0x9d/0x110 at addr
    ffff880000100000
  Read of size 2 by task syz-executor.1/16489
  page:ffffea0000004000 count:0 mapcount:-127 mapping:          (null)
  index:0x0
  page flags: 0xfffff00000000()
  page dumped because: kasan: bad access detected
  CPU: 1 PID: 16489 Comm: syz-executor.1 Not tainted
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
  rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
  Call Trace:
    [<ffffffffb119f309>] dump_stack+0x1e/0x20
    [<ffffffffb04af957>] kasan_report+0x577/0x950
    [<ffffffffb04ae652>] __asan_load2+0x62/0x80
    [<ffffffffb090f26d>] vgacon_invert_region+0x9d/0x110
    [<ffffffffb0a39d95>] invert_screen+0xe5/0x470
    [<ffffffffb0a21dcb>] set_selection+0x44b/0x12f0
    [<ffffffffb0a3bfae>] tioclinux+0xee/0x490
    [<ffffffffb0a1d114>] vt_ioctl+0xff4/0x2670
    [<ffffffffb0a0089a>] tty_ioctl+0x46a/0x1a10
    [<ffffffffb052db3d>] do_vfs_ioctl+0x5bd/0xc40
    [<ffffffffb052e2f2>] SyS_ioctl+0x132/0x170
    [<ffffffffb11c9b1b>] system_call_fastpath+0x22/0x27
    Memory state around the buggy address:
     ffff8800000fff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00
     00 00
     ffff8800000fff80: 00 00 00 00 00 00 00 00 00 00 00 00 00
     00 00 00
    >ffff880000100000: ff ff ff ff ff ff ff ff ff ff ff ff ff
     ff ff ff

It can be reproduce in the linux mainline by the program:
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <sys/ioctl.h>
  #include <linux/vt.h>

  struct tiocl_selection {
    unsigned short xs;      /* X start */
    unsigned short ys;      /* Y start */
    unsigned short xe;      /* X end */
    unsigned short ye;      /* Y end */
    unsigned short sel_mode; /* selection mode */
  };

  #define TIOCL_SETSEL    2
  struct tiocl {
    unsigned char type;
    unsigned char pad;
    struct tiocl_selection sel;
  };

  int main()
  {
    int fd = 0;
    const char *dev = "/dev/char/4:1";

    struct vt_consize v = {0};
    struct tiocl tioc = {0};

    fd = open(dev, O_RDWR, 0);

    v.v_rows = 3346;
    ioctl(fd, VT_RESIZEX, &v);

    tioc.type = TIOCL_SETSEL;
    ioctl(fd, TIOCLINUX, &tioc);

    return 0;
  }

When resize the screen, update the 'vc->vc_size_row' to the new_row_size,
but when 'set_origin' in 'vgacon_set_origin', vgacon use 'vga_vram_base'
for 'vc_origin' and 'vc_visible_origin', not 'vc_screenbuf'. It maybe
smaller than 'vc_screenbuf'. When TIOCLINUX, use the new_row_size to calc
the offset, it maybe larger than the vga_vram_size in vgacon driver, then
bad access.
Also, if set an larger screenbuf firstly, then set an more larger
screenbuf, when copy old_origin to new_origin, a bad access may happen.

So, If the screen size larger than vga_vram, resize screen should be
failed. This alse fix CVE-2020-8649 and CVE-2020-8647.

Linus pointed out that overflow checking seems absent. We're saved by
the existing bounds checks in vc_do_resize() with rather strict
limits:

	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
		return -EINVAL;

Fixes: 0aec4867dc ("[PATCH] SVGATextMode fix")
Reference: CVE-2020-8647 and CVE-2020-8649
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
[danvet: augment commit message to point out overflow safety]
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200304022429.37738-1-zhangxiaoxu5@huawei.com
2020-03-06 21:06:34 +01:00
Ulf Hansson
d2334a91a3 dt-bindings: arm: Fixup the DT bindings for hierarchical PSCI states
The hierarchical topology with power-domain should be described through
child nodes, rather than as currently described in the PSCI root node. Fix
this by adding a patternProperties with a corresponding reference to the
power-domain DT binding.

Additionally, update the example to conform to the new pattern, but also to
the adjusted domain-idle-state DT binding.

Fixes: a3f048b542 ("dt: psci: Update DT bindings to support hierarchical PSCI states")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[robh: Add missing allOf, tweak power-domain node name]
Signed-off-by: Rob Herring <robh@kernel.org>
2020-03-06 12:12:21 -06:00
Ulf Hansson
14ee09a05e dt-bindings: power: Extend nodename pattern for power-domain providers
The existing binding requires the nodename to have a '@', which is a bit
limiting for the wider use case. Therefore, let's extend the pattern to
allow either '@' or '-'.

Fixes: a3f048b542 ("dt: psci: Update DT bindings to support hierarchical PSCI states")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[robh: drop example change]
Signed-off-by: Rob Herring <robh@kernel.org>
2020-03-06 12:12:20 -06:00
Jens Axboe
c1e2148f8e io_uring: free fixed_file_data after RCU grace period
The percpu refcount protects this structure, and we can have an atomic
switch in progress when exiting. This makes it unsafe to just free the
struct normally, and can trigger the following KASAN warning:

BUG: KASAN: use-after-free in percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
Read of size 1 at addr ffff888181a19a30 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc4+ #5747
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
 <IRQ>
 dump_stack+0x76/0xa0
 print_address_description.constprop.0+0x3b/0x60
 ? percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
 ? percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
 __kasan_report.cold+0x1a/0x3d
 ? percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
 percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
 rcu_core+0x370/0x830
 ? percpu_ref_exit+0x50/0x50
 ? rcu_note_context_switch+0x7b0/0x7b0
 ? run_rebalance_domains+0x11d/0x140
 __do_softirq+0x10a/0x3e9
 irq_exit+0xd5/0xe0
 smp_apic_timer_interrupt+0x86/0x200
 apic_timer_interrupt+0xf/0x20
 </IRQ>
RIP: 0010:default_idle+0x26/0x1f0

Fix this by punting the final exit and free of the struct to RCU, then
we know that it's safe to do so. Jann suggested the approach of using a
double rcu callback to achieve this. It's important that we do a nested
call_rcu() callback, as otherwise the free could be ordered before the
atomic switch, even if the latter was already queued.

Reported-by: syzbot+e017e49c39ab484ac87a@syzkaller.appspotmail.com
Suggested-by: Jann Horn <jannh@google.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-06 10:15:21 -07:00