linux-toradex.git/drivers/firmware, branch v4.4.160

firmware: dmi_scan: Fix handling of empty DMI strings

2018-05-30T05:48:56+00:00

[ Upstream commit a7770ae194569e96a93c48aceb304edded9cc648 ]

The handling of empty DMI strings looks quite broken to me:
* Strings from 1 to 7 spaces are not considered empty.
* True empty DMI strings (string index set to 0) are not considered
  empty, and result in allocating a 0-char string.
* Strings with invalid index also result in allocating a 0-char
  string.
* Strings starting with 8 spaces are all considered empty, even if
  non-space characters follow (sounds like a weird thing to do, but
  I have actually seen occurrences of this in DMI tables before.)
* Strings which are considered empty are reported as 8 spaces,
  instead of being actually empty.

Some of these issues are the result of an off-by-one error in memcmp,
the rest is incorrect by design.

So let's get it square: missing strings and strings made of only
spaces, regardless of their length, should be treated as empty and
no memory should be allocated for them. All other strings are
non-empty and should be allocated.

Signed-off-by: Jean Delvare 
Fixes: 79da4721117f ("x86: fix DMI out of memory problems")
Cc: Parag Warudkar 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

efi/esrt: Cleanup bad memory map log messages

2017-12-20T09:04:56+00:00

[ Upstream commit 822f5845f710e57d7e2df1fd1ee00d6e19d334fe ]

The Intel Compute Stick STCK1A8LFC and Weibu F3C platforms both
log 2 error messages during boot:

   efi: requested map not found.
   esrt: ESRT header is not in the memory map.

Searching the web, this seems to affect many other platforms too.
Since these messages are logged as errors, they appear on-screen during
the boot process even when using the "quiet" boot parameter used by
distros.

Demote the ESRT error to a warning so that it does not appear on-screen,
and delete the error logging from efi_mem_desc_lookup; both callsites
of that function log more specific messages upon failure.

Out of curiosity I looked closer at the Weibu F3C. There is no entry in
the UEFI-provided memory map which corresponds to the ESRT pointer, but
hacking the code to map it anyway, the ESRT does appear to be valid with
2 entries.

Signed-off-by: Daniel Drake 
Cc: Matt Fleming 
Acked-by: Peter Jones 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

efi: Move some sysfs files to be read-only by root

2017-12-16T09:33:48+00:00

commit af97a77bc01ce49a466f9d4c0125479e2e2230b6 upstream.

Thanks to the scripts/leaking_addresses.pl script, it was found that
some EFI values should not be readable by non-root users.

So make them root-only, and to do that, add a __ATTR_RO_MODE() macro to
make this easier, and use it in other places at the same time.

Reported-by: Linus Torvalds 
Tested-by: Dave Young 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ard Biesheuvel 
Cc: H. Peter Anvin 
Cc: Matt Fleming 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20171206095010.24170-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

x86/efi-bgrt: Fix kernel panic when mapping BGRT data

2017-12-05T10:22:50+00:00

commit 50a0cb565246f20d59cdb161778531e4b19d35ac upstream.

Starting with this commit 35eb8b81edd4 ("x86/efi: Build our own page
table structures") efi regions have a separate page directory called
"efi_pgd". In order to access any efi region we have to first shift %cr3
to this page table. In the bgrt code we are trying to copy bgrt_header
and image, but these regions fall under "EFI_BOOT_SERVICES_DATA"
and to access these regions we have to shift %cr3 to efi_pgd and not
doing so will cause page fault as shown below.

[    0.251599] Last level dTLB entries: 4KB 64, 2MB 0, 4MB 0, 1GB 4
[    0.259126] Freeing SMP alternatives memory: 32K (ffffffff8230e000 - ffffffff82316000)
[    0.271803] BUG: unable to handle kernel paging request at fffffffefce35002
[    0.279740] IP: [] efi_bgrt_init+0x144/0x1fd
[    0.286383] PGD 300f067 PUD 0
[    0.289879] Oops: 0000 [#1] SMP
[    0.293566] Modules linked in:
[    0.297039] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.0-rc1-eywa-eywa-built-in-47041+ #2
[    0.306619] Hardware name: Intel Corporation Skylake Client platform/Skylake Y LPDDR3 RVP3, BIOS SKLSE2R1.R00.B104.B01.1511110114 11/11/2015
[    0.320925] task: ffffffff820134c0 ti: ffffffff82000000 task.ti: ffffffff82000000
[    0.329420] RIP: 0010:[]  [] efi_bgrt_init+0x144/0x1fd
[    0.338821] RSP: 0000:ffffffff82003f18  EFLAGS: 00010246
[    0.344852] RAX: fffffffefce35000 RBX: fffffffefce35000 RCX: fffffffefce2b000
[    0.352952] RDX: 000000008a82b000 RSI: ffffffff8235bb80 RDI: 000000008a835000
[    0.361050] RBP: ffffffff82003f30 R08: 000000008a865000 R09: ffffffffff202850
[    0.369149] R10: ffffffff811ad62f R11: 0000000000000000 R12: 0000000000000000
[    0.377248] R13: ffff88016dbaea40 R14: ffffffff822622c0 R15: ffffffff82003fb0
[    0.385348] FS:  0000000000000000(0000) GS:ffff88016d800000(0000) knlGS:0000000000000000
[    0.394533] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.401054] CR2: fffffffefce35002 CR3: 000000000300c000 CR4: 00000000003406f0
[    0.409153] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    0.417252] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    0.425350] Stack:
[    0.427638]  ffffffffffffffff ffffffff82256900 ffff88016dbaea40 ffffffff82003f40
[    0.436086]  ffffffff821bbce0 ffffffff82003f88 ffffffff8219c0c2 0000000000000000
[    0.444533]  ffffffff8219ba4a ffffffff822622c0 0000000000083000 00000000ffffffff
[    0.452978] Call Trace:
[    0.455763]  [] efi_late_init+0x9/0xb
[    0.461697]  [] start_kernel+0x463/0x47f
[    0.467928]  [] ? set_init_arg+0x55/0x55
[    0.474159]  [] ? early_idt_handler_array+0x120/0x120
[    0.481669]  [] x86_64_start_reservations+0x2a/0x2c
[    0.488982]  [] x86_64_start_kernel+0x13d/0x14c
[    0.495897] Code: 00 41 b4 01 48 8b 78 28 e8 09 36 01 00 48 85 c0 48 89 c3 75 13 48 c7 c7 f8 ac d3 81 31 c0 e8 d7 3b fb fe e9 b5 00 00 00 45 84 e4 <44> 8b 6b 02 74 0d be 06 00 00 00 48 89 df e8 ae 34 0$
[    0.518151] RIP  [] efi_bgrt_init+0x144/0x1fd
[    0.524888]  RSP 
[    0.528851] CR2: fffffffefce35002
[    0.532615] ---[ end trace 7b06521e6ebf2aea ]---
[    0.537852] Kernel panic - not syncing: Attempted to kill the idle task!

As said above one way to fix this bug is to shift %cr3 to efi_pgd but we
are not doing that way because it leaks inner details of how we switch
to EFI page tables into a new call site and it also adds duplicate code.
Instead, we remove the call to efi_lookup_mapped_addr() and always
perform early_mem*() instead of early_io*() because we want to remap RAM
regions and not I/O regions. We also delete efi_lookup_mapped_addr()
because we are no longer using it.

Signed-off-by: Sai Praneeth Prakhya 
Reported-by: Wendy Wang 
Cc: Borislav Petkov 
Cc: Josh Triplett 
Cc: Ricardo Neri 
Cc: Ravi Shankar 
Signed-off-by: Matt Fleming 
Cc: "Ghannam, Yazen" 
Signed-off-by: Greg Kroah-Hartman

drivers: firmware: psci: drop duplicate const from psci_of_match

2017-10-08T08:14:20+00:00

commit 1d2d8de44a6c20af262b4c3d3b93ef7ec3c5488e upstream.

This is to fix below sparse warning:
drivers/firmware/psci.c:mmm:nn: warning: duplicate const

Signed-off-by: Jisheng Zhang 
Signed-off-by: Lorenzo Pieralisi 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

efi: Expose non-blocking set_variable() wrapper to efivars

2016-05-04T21:48:49+00:00

commit 9c6672ac9c91f7eb1ec436be1442b8c26d098e55 upstream.

Commit 6d80dba1c9fe ("efi: Provide a non-blocking SetVariable()
operation") implemented a non-blocking alternative for the UEFI
SetVariable() invocation performed by efivars, since it may
occur in atomic context. However, this version of the function
was never exposed via the efivars struct, so the non-blocking
versions was not actually callable. Fix that.

Signed-off-by: Ard Biesheuvel 
Signed-off-by: Matt Fleming 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-efi@vger.kernel.org
Fixes: 6d80dba1c9fe ("efi: Provide a non-blocking SetVariable() operation")
Link: http://lkml.kernel.org/r/1454364428-494-2-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

efi: Fix out-of-bounds read in variable_matches()

2016-05-04T21:48:48+00:00

commit 630ba0cc7a6dbafbdee43795617c872b35cde1b4 upstream.

The variable_matches() function can currently read "var_name[len]", for
example when:

 - var_name[0] == 'a',
 - len == 1
 - match_name points to the NUL-terminated string "ab".

This function is supposed to accept "var_name" inputs that are not
NUL-terminated (hence the "len" parameter"). Document the function, and
access "var_name[*match]" only if "*match" is smaller than "len".

Reported-by: Chris Wilson 
Signed-off-by: Laszlo Ersek 
Cc: Peter Jones 
Cc: Matthew Garrett 
Cc: Jason Andryuk 
Cc: Jani Nikula 
Link: http://thread.gmane.org/gmane.comp.freedesktop.xorg.drivers.intel/86906
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi: Add pstore variables to the deletion whitelist

2016-03-03T23:07:09+00:00

commit e246eb568bc4cbbdd8a30a3c11151ff9b7ca7312 upstream.

Laszlo explains why this is a good idea,

 'This is because the pstore filesystem can be backed by UEFI variables,
  and (for example) a crash might dump the last kilobytes of the dmesg
  into a number of pstore entries, each entry backed by a separate UEFI
  variable in the above GUID namespace, and with a variable name
  according to the above pattern.

  Please see "drivers/firmware/efi/efi-pstore.c".

  While this patch series will not prevent the user from deleting those
  UEFI variables via the pstore filesystem (i.e., deleting a pstore fs
  entry will continue to delete the backing UEFI variable), I think it
  would be nice to preserve the possibility for the sysadmin to delete
  Linux-created UEFI variables that carry portions of the crash log,
  *without* having to mount the pstore filesystem.'

There's also no chance of causing machines to become bricked by
deleting these variables, which is the whole purpose of excluding
things from the whitelist.

Use the LINUX_EFI_CRASH_GUID guid and a wildcard '*' for the match so
that we don't have to update the string in the future if new variable
name formats are created for crash dump variables.

Reported-by: Laszlo Ersek 
Acked-by: Peter Jones 
Tested-by: Peter Jones 
Cc: Matthew Garrett 
Cc: "Lee, Chun-Yi" 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi: Make efivarfs entries immutable by default

2016-03-03T23:07:09+00:00

commit ed8b0de5a33d2a2557dce7f9429dca8cb5bc5879 upstream.

"rm -rf" is bricking some peoples' laptops because of variables being
used to store non-reinitializable firmware driver data that's required
to POST the hardware.

These are 100% bugs, and they need to be fixed, but in the mean time it
shouldn't be easy to *accidentally* brick machines.

We have to have delete working, and picking which variables do and don't
work for deletion is quite intractable, so instead make everything
immutable by default (except for a whitelist), and make tools that
aren't quite so broad-spectrum unset the immutable flag.

Signed-off-by: Peter Jones 
Tested-by: Lee, Chun-Yi 
Acked-by: Matthew Garrett 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi: Make our variable validation list include the guid

2016-03-03T23:07:09+00:00

commit 8282f5d9c17fe15a9e658c06e3f343efae1a2a2f upstream.

All the variables in this list so far are defined to be in the global
namespace in the UEFI spec, so this just further ensures we're
validating the variables we think we are.

Including the guid for entries will become more important in future
patches when we decide whether or not to allow deletion of variables
based on presence in this list.

Signed-off-by: Peter Jones 
Tested-by: Lee, Chun-Yi 
Acked-by: Matthew Garrett 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman