linux-stable.git/drivers/firmware/efi, branch linux-5.5.y

efi/x86: Ignore the memory attributes table on i386

2020-04-17T14:11:56+00:00

[ Upstream commit dd09fad9d2caad2325a39b766ce9e79cfc690184 ]

Commit:

  3a6b6c6fb23667fa ("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: 3a6b6c6fb23667fa ("efi: Make EFI_MEMORY_ATTRIBUTES_TABLE ... ")
Tested-by: Arvind Sankar 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Ingo Molnar 
Link: https://lore.kernel.org/r/20200304165917.5893-1-ardb@kernel.org
Link: https://lore.kernel.org/r/20200308080859.21568-21-ardb@kernel.org
Signed-off-by: Sasha Levin

efi: Add a sanity check to efivar_store_raw()

2020-03-18T06:19:13+00:00

commit d6c066fda90d578aacdf19771a027ed484a79825 upstream.

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 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Ingo Molnar 
Cc: 
Link: https://lore.kernel.org/r/20200305084041.24053-3-vdronov@redhat.com
Link: https://lore.kernel.org/r/20200308080859.21568-25-ardb@kernel.org
Signed-off-by: Greg Kroah-Hartman

efi: Fix a race and a buffer overflow while reading efivars via sysfs

2020-03-18T06:19:13+00:00

commit 286d3250c9d6437340203fb64938bea344729a0e upstream.

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: e14ab23dde12b80d ("efivars: efivar_entry API")
Reported-by: Bob Sanders  and the LTP testsuite
Signed-off-by: Vladis Dronov 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Ingo Molnar 
Cc: 
Link: https://lore.kernel.org/r/20200305084041.24053-2-vdronov@redhat.com
Link: https://lore.kernel.org/r/20200308080859.21568-24-ardb@kernel.org
Signed-off-by: Greg Kroah-Hartman

efi: READ_ONCE rng seed size before munmap

2020-03-12T06:18:48+00:00

commit be36f9e7517e17810ec369626a128d7948942259 upstream.

This function is consistent with using size instead of seed->size
(except for one place that this patch fixes), but it reads seed->size
without using READ_ONCE, which means the compiler might still do
something unwanted. So, this commit simply adds the READ_ONCE
wrapper.

Fixes: 636259880a7e ("efi: Add support for seeding the RNG from a UEFI ...")
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Ingo Molnar 
Cc: linux-efi@vger.kernel.org
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Link: https://lore.kernel.org/r/20200217123354.21140-1-Jason@zx2c4.com
Link: https://lore.kernel.org/r/20200221084849.26878-5-ardb@kernel.org
Signed-off-by: Greg Kroah-Hartman

efi/arm: Defer probe of PCIe backed efifb on DT systems

2020-02-24T07:38:36+00:00

[ Upstream commit 64c8a0cd0a535891d5905c3a1651150f0f141439 ]

The new of_devlink support breaks PCIe probing on ARM platforms booting
via UEFI if the firmware exposes a EFI framebuffer that is backed by a
PCI device. The reason is that the probing order gets reversed,
resulting in a resource conflict on the framebuffer memory window when
the PCIe probes last, causing it to give up entirely.

Given that we rely on PCI quirks to deal with EFI framebuffers that get
moved around in memory, we cannot simply drop the memory reservation, so
instead, let's use the device link infrastructure to register this
dependency, and force the probing to occur in the expected order.

Co-developed-by: Saravana Kannan 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Saravana Kannan 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Ingo Molnar 
Link: https://lore.kernel.org/r/20200113172245.27925-9-ardb@kernel.org
Signed-off-by: Sasha Levin

efi/libstub/random: Initialize pointer variables to zero for mixed mode

2019-12-25T09:46:06+00:00

Commit:

  0d95981438c3 ("x86: efi/random: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table")

causes the drivers/efi/libstub/random.c code to get used on x86 for the first time.

But this code was not written with EFI mixed mode in mind (running a 64
bit kernel on 32 bit EFI firmware), this causes the kernel to crash during
early boot when running in mixed mode.

The problem is that in mixed mode pointers are 64 bit, but when running on
a 32 bit firmware, EFI calls which return a pointer value by reference only
fill the lower 32 bits of the passed pointer, leaving the upper 32 bits
uninitialized which leads to crashes.

This commit fixes this by initializing pointers which are passed by
reference to EFI calls to NULL before passing them, so that the upper 32
bits are initialized to 0.

Signed-off-by: Hans de Goede 
Signed-off-by: Ard Biesheuvel 
Cc: Arvind Sankar 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-efi@vger.kernel.org
Fixes: 0d95981438c3 ("x86: efi/random: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table")
Link: https://lkml.kernel.org/r/20191224132909.102540-3-ardb@kernel.org
Signed-off-by: Ingo Molnar

efi/earlycon: Fix write-combine mapping on x86

2019-12-25T09:46:06+00:00

On x86, until PAT is initialized, WC translates into UC-. Since we
calculate and store pgprot_writecombine(PAGE_KERNEL) when earlycon is
initialized, this means we actually use UC- mappings instead of WC
mappings, which makes scrolling very slow.

Instead store a boolean flag to indicate whether we want to use
writeback or write-combine mappings, and recalculate the actual pgprot_t
we need on every mapping. Once PAT is initialized, we will start using
write-combine mappings, which speeds up the scrolling considerably.

Signed-off-by: Arvind Sankar 
Signed-off-by: Ard Biesheuvel 
Cc: Hans de Goede 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-efi@vger.kernel.org
Fixes: 69c1f396f25b ("efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation")
Link: https://lkml.kernel.org/r/20191224132909.102540-2-ardb@kernel.org
Signed-off-by: Ingo Molnar

Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-12-17T18:39:55+00:00

Pull EFI fixes from Ingo Molnar:
 "Protect presistent EFI memory reservations from kexec, fix EFIFB early
  console, EFI stub graphics output fixes and other misc fixes."

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Don't attempt to map RCI2 config table if it doesn't exist
  efi/earlycon: Remap entire framebuffer after page initialization
  efi: Fix efi_loaded_image_t::unload type
  efi/gop: Fix memory leak in __gop_query32/64()
  efi/gop: Return EFI_SUCCESS if a usable GOP was found
  efi/gop: Return EFI_NOT_FOUND if there are no usable GOPs
  efi/memreserve: Register reservations as 'reserved' in /proc/iomem

efi: Don't attempt to map RCI2 config table if it doesn't exist

2019-12-10T11:13:02+00:00

Commit:

  1c5fecb61255aa12 ("efi: Export Runtime Configuration Interface table to sysfs")

... added support for a Dell specific UEFI configuration table, but
failed to take into account that mapping the table should not be
attempted unless the table actually exists. If it doesn't exist,
the code usually fails silently unless pr_debug() prints are
enabled. However, on 32-bit PAE x86, the splat below is produced due
to the attempt to map the placeholder value EFI_INVALID_TABLE_ADDR
which we use for non-existing UEFI configuration tables, and which
equals ULONG_MAX.

   memremap attempted on mixed range 0x00000000ffffffff size: 0x1e
   WARNING: CPU: 1 PID: 1 at kernel/iomem.c:81 memremap+0x1a3/0x1c0
   Modules linked in:
   CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.4.2-smp-mine #1
   Hardware name: Hewlett-Packard HP Z400 Workstation/0B4Ch, BIOS 786G3 v03.61 03/05/2018
   EIP: memremap+0x1a3/0x1c0
  ...
   Call Trace:
    ? map_properties+0x473/0x473
    ? efi_rci2_sysfs_init+0x2c/0x154
    ? map_properties+0x473/0x473
    ? do_one_initcall+0x49/0x1d4
    ? parse_args+0x1e8/0x2a0
    ? do_early_param+0x7a/0x7a
    ? kernel_init_freeable+0x139/0x1c2
    ? rest_init+0x8e/0x8e
    ? kernel_init+0xd/0xf2
    ? ret_from_fork+0x2e/0x38

Fix this by checking whether the table exists before attempting to map it.

Reported-by: Richard Narron 
Tested-by: Richard Narron 
Signed-off-by: Ard Biesheuvel 
Cc: linux-efi@vger.kernel.org
Fixes: 1c5fecb61255aa12 ("efi: Export Runtime Configuration Interface table to sysfs")
Link: https://lkml.kernel.org/r/20191210090945.11501-2-ardb@kernel.org
Signed-off-by: Ingo Molnar

treewide: Use sizeof_field() macro

2019-12-09T18:36:44+00:00

Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except
at places where these are defined. Later patches will remove the unused
definition of FIELD_SIZEOF().

This patch is generated using following script:

EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h"

git grep -l -e "\bFIELD_SIZEOF\b" | while read file;
do

	if [[ "$file" =~ $EXCLUDE_FILES ]]; then
		continue
	fi
	sed -i  -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file;
done

Signed-off-by: Pankaj Bharadiya 
Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com
Co-developed-by: Kees Cook 
Signed-off-by: Kees Cook 
Acked-by: David Miller  # for net