Commit Graph

2349 Commits

Author SHA1 Message Date
Javier Martinez Canillas
578c95298b kern: Add lockdown support
When the GRUB starts on a secure boot platform, some commands can be
used to subvert the protections provided by the verification mechanism and
could lead to booting untrusted system.

To prevent that situation, allow GRUB to be locked down. That way the code
may check if GRUB has been locked down and further restrict the commands
that are registered or what subset of their functionality could be used.

The lockdown support adds the following components:

* The grub_lockdown() function which can be used to lockdown GRUB if,
  e.g., UEFI Secure Boot is enabled.

* The grub_is_lockdown() function which can be used to check if the GRUB
  was locked down.

* A verifier that flags OS kernels, the GRUB modules, Device Trees and ACPI
  tables as GRUB_VERIFY_FLAGS_DEFER_AUTH to defer verification to other
  verifiers. These files are only successfully verified if another registered
  verifier returns success. Otherwise, the whole verification process fails.

  For example, PE/COFF binaries verification can be done by the shim_lock
  verifier which validates the signatures using the shim_lock protocol.
  However, the verification is not deferred directly to the shim_lock verifier.
  The shim_lock verifier is hooked into the verification process instead.

* A set of grub_{command,extcmd}_lockdown functions that can be used by
  code registering command handlers, to only register unsafe commands if
  the GRUB has not been locked down.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:15 +01:00
Marco A Benatto
5e280caa65 efi: Move the shim_lock verifier to the GRUB core
Move the shim_lock verifier from its own module into the core image. The
Secure Boot lockdown mechanism has the intent to prevent the load of any
unsigned code or binary when Secure Boot is enabled.

The reason is that GRUB must be able to prevent executing untrusted code
if UEFI Secure Boot is enabled, without depending on external modules.

Signed-off-by: Marco A Benatto <mbenatto@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:15 +01:00
Marco A Benatto
9e95f45cee verifiers: Move verifiers API to kernel image
Move verifiers API from a module to the kernel image, so it can be
used there as well. There are no functional changes in this patch.

Signed-off-by: Marco A Benatto <mbenatto@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:15 +01:00
Glenn Washburn
3ab19ba3b1 misc: Add grub_log2ull() macro for calculating log base 2 of 64-bit integers
Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-18 23:08:14 +01:00
Glenn Washburn
9b4e8f0c4b mips: Enable __clzdi2()
This patch is similar to commit 9dab2f51e (sparc: Enable __clzsi2() and
__clzdi2()) but for MIPS target and __clzdi2() only, __clzsi2() was
already enabled.

Suggested-by: Daniel Kiper <dkiper@net-space.pl>
Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-18 23:04:36 +01:00
Glenn Washburn
9c3149a2f2 luks2: Better error handling when setting up the cryptodisk
Do some sanity checking on data coming from the LUKS2 header. If segment.size
is "dynamic", verify that the offset is not past the end of disk. Otherwise,
check for errors from grub_strtoull() when converting segment size from
string. If a GRUB_ERR_BAD_NUMBER error was returned, then the string was
not a valid parsable number, so skip the key. If GRUB_ERR_OUT_OF_RANGE was
returned, then there was an overflow in converting to a 64-bit unsigned
integer. So this could be a very large disk (perhaps large RAID array).
In this case skip the key too. Additionally, enforce some other limits
and fail if needed.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-18 23:00:28 +01:00
Glenn Washburn
cf3a3acff0 cryptodisk: Properly handle non-512 byte sized sectors
By default, dm-crypt internally uses an IV that corresponds to 512-byte
sectors, even when a larger sector size is specified. What this means is
that when using a larger sector size, the IV is incremented every sector.
However, the amount the IV is incremented is the number of 512 byte blocks
in a sector (i.e. 8 for 4K sectors). Confusingly the IV does not correspond
to the number of, for example, 4K sectors. So each 512 byte cipher block in
a sector will be encrypted with the same IV and the IV will be incremented
afterwards by the number of 512 byte cipher blocks in the sector.

There are some encryption utilities which do it the intuitive way and have
the IV equal to the sector number regardless of sector size (ie. the fifth
sector would have an IV of 4 for each cipher block). And this is supported
by dm-crypt with the iv_large_sectors option and also cryptsetup as of 2.3.3
with the --iv-large-sectors, though not with LUKS headers (only with --type
plain). However, support for this has not been included as grub does not
support plain devices right now.

One gotcha here is that the encrypted split keys are encrypted with a hard-
coded 512-byte sector size. So even if your data is encrypted with 4K sector
sizes, the split key encrypted area must be decrypted with a block size of
512 (ie the IV increments every 512 bytes). This made these changes less
aesthetically pleasing than desired.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-12 01:19:05 +01:00
Glenn Washburn
b34cb38795 cryptodisk: Add macros GRUB_TYPE_U_MAX/MIN(type) to replace literals
Add GRUB_TYPE_U_MAX/MIN(type) macros to get the max/min values for an
unsigned number with size of type.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-12 01:19:04 +01:00
Glenn Washburn
3e5f7f5112 cryptodisk: Add macro GRUB_TYPE_BITS() to replace some literals
The new macro GRUB_TYPE_BITS(type) returns the number of bits
allocated for type.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-12 01:19:04 +01:00
Glenn Washburn
8e8b2316ac misc: Add parentheses around ALIGN_UP() and ALIGN_DOWN() arguments
This ensures that expected order of operations is preserved when arguments
are expressions.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-12 01:19:04 +01:00
Glenn Washburn
880dfd8f40 disk: Rename grub_disk_get_size() to grub_disk_native_sectors()
The function grub_disk_get_size() is confusingly named because it actually
returns a sector count where the sectors are sized in the GRUB native sector
size. Rename to something more appropriate.

Suggested-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-12 01:19:03 +01:00
Glenn Washburn
407ddead69 disk: Move hardcoded max disk size literal to a GRUB_DISK_MAX_SECTORS in disk.h
There is a hardcoded maximum disk size that can be read or written from,
currently set at 1 EiB in grub_disk_adjust_range(). Move the literal into a
macro in disk.h, so our assumptions are more visible. This hard coded limit
does not prevent using larger disks, just GRUB won't read/write past the
limit. The comment accompanying this restriction didn't quite make sense to
me, so its been modified too.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-12 01:19:03 +01:00
Vladimir Serbinenko
5fd18f77ee mbr: Warn if MBR gap is small and user uses advanced modules
We don't want to support small MBR gap in pair with anything but the
simplest config of biosdisk + part_msdos + simple filesystem. In this
path "simple filesystems" are all current filesystems except ZFS and
Btrfs.

Signed-off-by: Vladimir Serbinenko <phcoder@google.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-12 01:19:03 +01:00
Daniel Kiper
a195dbb677 loader/linux: Report the UEFI Secure Boot status to the Linux kernel
Now that the GRUB has a grub_efi_get_secureboot() function to check the
UEFI Secure Boot status, use it to report that to the Linux kernel.

Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Marco A Benatto <mbenatto@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-12 01:19:03 +01:00
Daniel Kiper
d7e54b2e5f efi: Add secure boot detection
Introduce grub_efi_get_secureboot() function which returns whether
UEFI Secure Boot is enabled or not on UEFI systems.

Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Marco A Benatto <mbenatto@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-11 13:56:22 +01:00
Daniel Kiper
ac5c936754 efi: Add a function to read EFI variables with attributes
It will be used to properly detect and report UEFI Secure Boot status to
the x86 Linux kernel. The functionality will be added by subsequent patches.

Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Marco A Benatto <mbenatto@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-11 13:55:31 +01:00
Daniel Kiper
04ae030d0e efi: Return grub_efi_status_t from grub_efi_get_variable()
This is needed to properly detect and report UEFI Secure Boot status
to the x86 Linux kernel. The functionality will be added by subsequent
patches.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Marco A Benatto <mbenatto@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-11 13:54:54 +01:00
Daniel Kiper
f76a27996c efi: Make shim_lock GUID and protocol type public
The GUID will be used to properly detect and report UEFI Secure Boot
status to the x86 Linux kernel. The functionality will be added by
subsequent patches. The shim_lock protocol type is made public for
completeness.

Additionally, fix formatting of four preceding GUIDs.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Marco A Benatto <mbenatto@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-11 13:54:23 +01:00
Javier Martinez Canillas
97c20f2412 include/grub/i386/linux.h: Include missing <grub/types.h> header
This header uses types defined in <grub/types.h> but does not include it,
which leads to compile errors like the following:

In file included from ../include/grub/cpu/linux.h:19,
                 from kern/efi/sb.c:21:
../include/grub/i386/linux.h:80:3: error: unknown type name ‘grub_uint64_t’
   80 |   grub_uint64_t addr;

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-11 13:53:18 +01:00
Glenn Washburn
d78ce33e60 cryptodisk: Rename "offset" in grub_cryptodisk_t to "offset_sectors"
This makes it clear that the offset represents sectors, not bytes, in
order to improve readability.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-11-20 15:33:41 +01:00
Glenn Washburn
535998c2e0 cryptodisk: Rename "total_length" field in grub_cryptodisk_t to "total_sectors"
This creates an alignment with grub_disk_t naming of the same field and is
more intuitive as to how it should be used.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-11-20 15:33:41 +01:00
Glenn Washburn
f0715577c2 types: Define GRUB_CHAR_BIT based on compiler macro instead of using literal
Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-11-20 15:33:40 +01:00
Javier Martinez Canillas
71dd2ef76f include/grub/arm64/linux.h: Include missing <grub/types.h> header
This header uses types defined in <grub/types.h> but does not include it,
which leads to compile errors like the following:

../include/grub/cpu/linux.h:27:3: error: unknown type name ‘grub_uint32_t’
   27 |   grub_uint32_t code0;  /* Executable code */
      |   ^~~~~~~~~~~~~

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-11-20 15:33:40 +01:00
Javier Martinez Canillas
11fa824dde include/grub/arm/system.h: Include missing <grub/symbol.h> header
The header uses the EXPORT_FUNC() macro defined in <grub/types.h> but
doesn't include it, which leads to the following compile error on arm:

../include/grub/cpu/system.h:12:13: error: ‘EXPORT_FUNC’ declared as function returning a function
   12 | extern void EXPORT_FUNC(grub_arm_disable_caches_mmu) (void);
      |             ^~~~~~~~~~~
../include/grub/cpu/system.h:12:1: warning: parameter names (without types) in function declaration
   12 | extern void EXPORT_FUNC(grub_arm_disable_caches_mmu) (void);
      | ^~~~~~
make[3]: *** [Makefile:36581: kern/efi/kernel_exec-sb.o] Error 1

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-11-20 15:33:40 +01:00
Glenn Washburn
2df2912266 crypto: Remove GPG_ERROR_CFLAGS from gpg_err_code_t enum
This was probably added by accident when originally creating the file.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-09-18 22:31:30 +02:00
Glenn Washburn
c98a78ae81 lexer: char const * should be const char *
Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-09-18 22:31:30 +02:00
Tianjia Zhang
6efd04f314 efi/tpm: Remove unused functions and structures
Although the tpm_execute() series of functions are defined they are not
used anywhere. Several structures in the include/grub/efi/tpm.h header
file are not used too. There is even nonexistent grub_tpm_init()
declaration in this header. Delete all that unneeded stuff.

If somebody needs the functionality implemented in the dropped code then
he/she can re-add it later. Now it needlessly increases the GRUB
code/image size.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-09-18 22:31:29 +02:00
Daniel Kiper
1e81bf6d2d efi/tpm: Fix typo in grub_efi_tpm2_protocol struct
Rename get_active_pcr_blanks() to get_active_pcr_banks().

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
2020-09-18 21:23:21 +02:00
Glenn Washburn
e1b0992a8d cryptodisk: Fix incorrect calculation of start sector
Here dev is a grub_cryptodisk_t and dev->offset is offset in sectors of size
native to the cryptodisk device. The sector is correctly transformed into
native grub sector size, but then added to dev->offset which is not
transformed. It would be nice if the type system would help us with this.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-09-11 15:51:04 +02:00
Alexey Makhalov
f7bd9986f6 efi: Fix use-after-free in halt/reboot path
commit 92bfc33db9 ("efi: Free malloc regions on exit")
introduced memory freeing in grub_efi_fini(), which is
used not only by exit path but by halt/reboot one as well.
As result of memory freeing, code and data regions used by
modules, such as halt, reboot, acpi (used by halt) also got
freed. After return to module code, CPU executes, filled
by UEFI firmware (tested with edk2), 0xAFAFAFAF pattern as
a code. Which leads to #UD exception later.

grub> halt
!!!! X64 Exception Type - 06(#UD - Invalid Opcode)  CPU Apic ID - 00000000 !!!!
RIP  - 0000000003F4EC28, CS  - 0000000000000038, RFLAGS - 0000000000200246
RAX  - 0000000000000000, RCX - 00000000061DA188, RDX - 0A74C0854DC35D41
RBX  - 0000000003E10E08, RSP - 0000000007F0F860, RBP - 0000000000000000
RSI  - 00000000064DB768, RDI - 000000000832C5C3
R8   - 0000000000000002, R9  - 0000000000000000, R10 - 00000000061E2E52
R11  - 0000000000000020, R12 - 0000000003EE5C1F, R13 - 00000000061E0FF4
R14  - 0000000003E10D80, R15 - 00000000061E2F60
DS   - 0000000000000030, ES  - 0000000000000030, FS  - 0000000000000030
GS   - 0000000000000030, SS  - 0000000000000030
CR0  - 0000000080010033, CR2 - 0000000000000000, CR3 - 0000000007C01000
CR4  - 0000000000000668, CR8 - 0000000000000000
DR0  - 0000000000000000, DR1 - 0000000000000000, DR2 - 0000000000000000
DR3  - 0000000000000000, DR6 - 00000000FFFF0FF0, DR7 - 0000000000000400
GDTR - 00000000079EEA98 0000000000000047, LDTR - 0000000000000000
IDTR - 0000000007598018 0000000000000FFF,   TR - 0000000000000000
FXSAVE_STATE - 0000000007F0F4C0

Proposal here is to continue to free allocated memory for
exit boot services path but keep it for halt/reboot path
as it won't be much security concern here.
Introduced GRUB_LOADER_FLAG_EFI_KEEP_ALLOCATED_MEMORY
loader flag to be used by efi halt/reboot path.

Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-07-29 16:55:48 +02:00
Peter Jones
d2cf823d0e efi: Fix some malformed device path arithmetic errors
Several places we take the length of a device path and subtract 4 from
it, without ever checking that it's >= 4. There are also cases where
this kind of malformation will result in unpredictable iteration,
including treating the length from one dp node as the type in the next
node. These are all errors, no matter where the data comes from.

This patch adds a checking macro, GRUB_EFI_DEVICE_PATH_VALID(), which
can be used in several places, and makes GRUB_EFI_NEXT_DEVICE_PATH()
return NULL and GRUB_EFI_END_ENTIRE_DEVICE_PATH() evaluate as true when
the length is too small. Additionally, it makes several places in the
code check for and return errors in these cases.

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-07-29 16:55:48 +02:00
Chris Coulson
426f57383d script: Avoid a use-after-free when redefining a function during execution
Defining a new function with the same name as a previously defined
function causes the grub_script and associated resources for the
previous function to be freed. If the previous function is currently
executing when a function with the same name is defined, this results
in use-after-frees when processing subsequent commands in the original
function.

Instead, reject a new function definition if it has the same name as
a previously defined function, and that function is currently being
executed. Although a behavioural change, this should be backwards
compatible with existing configurations because they can't be
dependent on the current behaviour without being broken.

Fixes: CVE-2020-15706

Signed-off-by: Chris Coulson <chris.coulson@canonical.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-07-29 16:55:48 +02:00
Chris Coulson
1a8d9c9b4a script: Remove unused fields from grub_script_function struct
Signed-off-by: Chris Coulson <chris.coulson@canonical.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-07-29 16:55:48 +02:00
Alexey Makhalov
61ff5602fe relocator: Protect grub_relocator_alloc_chunk_align() max_addr against integer underflow
This commit introduces integer underflow mitigation in max_addr calculation
in grub_relocator_alloc_chunk_align() invocation.

It consists of 2 fixes:
  1. Introduced grub_relocator_alloc_chunk_align_safe() wrapper function to perform
     sanity check for min/max and size values, and to make safe invocation of
     grub_relocator_alloc_chunk_align() with validated max_addr value. Replace all
     invocations such as grub_relocator_alloc_chunk_align(..., min_addr, max_addr - size, size, ...)
     by grub_relocator_alloc_chunk_align_safe(..., min_addr, max_addr, size, ...).
  2. Introduced UP_TO_TOP32(s) macro for the cases where max_addr is 32-bit top
     address (0xffffffff - size + 1) or similar.

Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-07-29 16:55:48 +02:00
Peter Jones
f725fa7cb2 calloc: Use calloc() at most places
This modifies most of the places we do some form of:

  X = malloc(Y * Z);

to use calloc(Y, Z) instead.

Among other issues, this fixes:
  - allocation of integer overflow in grub_png_decode_image_header()
    reported by Chris Coulson,
  - allocation of integer overflow in luks_recover_key()
    reported by Chris Coulson,
  - allocation of integer overflow in grub_lvm_detect()
    reported by Chris Coulson.

Fixes: CVE-2020-14308

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-07-29 16:55:47 +02:00
Peter Jones
64e26162eb calloc: Make sure we always have an overflow-checking calloc() available
This tries to make sure that everywhere in this source tree, we always have
an appropriate version of calloc() (i.e. grub_calloc(), xcalloc(), etc.)
available, and that they all safely check for overflow and return NULL when
it would occur.

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-07-29 16:55:47 +02:00
Peter Jones
68708c4503 safemath: Add some arithmetic primitives that check for overflow
This adds a new header, include/grub/safemath.h, that includes easy to
use wrappers for __builtin_{add,sub,mul}_overflow() declared like:

  bool OP(a, b, res)

where OP is grub_add, grub_sub or grub_mul. OP() returns true in the
case where the operation would overflow and res is not modified.
Otherwise, false is returned and the operation is executed.

These arithmetic primitives require newer compiler versions. So, bump
these requirements in the INSTALL file too.

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-07-29 16:55:47 +02:00
Tianjia Zhang
c867185b81 tpm: Rename function grub_tpm_log_event() to grub_tpm_measure()
grub_tpm_log_event() and grub_tpm_measure() are two functions that
have the same effect. So, keep grub_tpm_log_event() and rename it
to grub_tpm_measure(). This way we get also a more clear semantics.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-05-15 15:37:28 +02:00
Hans de Goede
12341958d2 kern/term: Accept ESC, F4 and holding SHIFT as user interrupt keys
On some devices the ESC key is the hotkey to enter the BIOS/EFI setup
screen, making it really hard to time pressing it right. Besides that
ESC is also pretty hard to discover for a user who does not know it
will unhide the menu.

This commit makes F4, which was chosen because is not used as a hotkey
to enter the BIOS setup by any vendor, also interrupt sleeps / stop the
menu countdown.

This solves the ESC gets into the BIOS setup and also somewhat solves
the discoverability issue, but leaves the timing issue unresolved.

This commit fixes the timing issue by also adding support for keeping
SHIFT pressed during boot to stop the menu countdown. This matches
what Ubuntu is doing, which should also help with discoverability.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-04-21 22:13:44 +02:00
Hans de Goede
2d7c3abd87 efi/console: Do not set text-mode until we actually need it
If we're running with a hidden menu we may never need text mode, so do not
change the video-mode to text until we actually need it.

This allows to boot a machine without unnecessary graphical transitions and
provide a seamless boot experience to users.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-04-21 22:13:14 +02:00
Hans de Goede
5bcdf67642 kern/term: Make grub_getkeystatus() helper function available everywhere
Move grub_getkeystatushelper() function from grub-core/commands/keystatus.c
to grub-core/kern/term.c and export it so that it can be used outside of
the keystatus command code too.

There's no logic change in this patch. The function definition is moved so
it can be called from grub-core/kern/term.c in a subsequent patch. It will
be used to determine if a SHIFT key has was held down and use that also to
interrupt the countdown, without the need to press a key at the right time.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-04-21 22:08:52 +02:00
Flavio Suligoi
2a6308b954 efi: Add missed space in GRUB_EFI_GLOBAL_VARIABLE_GUID
Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-03-31 12:17:03 +02:00
Michael Chang
68006d1732 zfs: Fix gcc10 error -Werror=zero-length-bounds
We bumped into the build error while testing gcc-10 pre-release.

In file included from ../../include/grub/file.h:22,
		from ../../grub-core/fs/zfs/zfs.c:34:
../../grub-core/fs/zfs/zfs.c: In function 'zap_leaf_lookup':
../../grub-core/fs/zfs/zfs.c:2263:44: error: array subscript '<unknown>' is outside the bounds of an interior zero-length array 'grub_uint16_t[0]' {aka 'short unsigned int[0]'} [-Werror=zero-length-bounds]
2263 |   for (chunk = grub_zfs_to_cpu16 (l->l_hash[LEAF_HASH (blksft, h, l)], endian);
../../include/grub/types.h:241:48: note: in definition of macro 'grub_le_to_cpu16'
 241 | # define grub_le_to_cpu16(x) ((grub_uint16_t) (x))
     |                                                ^
../../grub-core/fs/zfs/zfs.c:2263:16: note: in expansion of macro 'grub_zfs_to_cpu16'
2263 |   for (chunk = grub_zfs_to_cpu16 (l->l_hash[LEAF_HASH (blksft, h, l)], endian);
     |                ^~~~~~~~~~~~~~~~~
In file included from ../../grub-core/fs/zfs/zfs.c:48:
../../include/grub/zfs/zap_leaf.h:72:16: note: while referencing 'l_hash'
  72 |  grub_uint16_t l_hash[0];
     |                ^~~~~~

Here I'd like to quote from the gcc document [1] which seems best to
explain what is going on here.

"Although the size of a zero-length array is zero, an array member of
this kind may increase the size of the enclosing type as a result of
tail padding. The offset of a zero-length array member from the
beginning of the enclosing structure is the same as the offset of an
array with one or more elements of the same type. The alignment of a
zero-length array is the same as the alignment of its elements.

Declaring zero-length arrays in other contexts, including as interior
members of structure objects or as non-member objects, is discouraged.
Accessing elements of zero-length arrays declared in such contexts is
undefined and may be diagnosed."

The l_hash[0] is apparnetly an interior member to the enclosed structure
while l_entries[0] is the trailing member. And the offending code tries
to access members in l_hash[0] array that triggers the diagnose.

Given that the l_entries[0] is used to get proper alignment to access
leaf chunks, we can accomplish the same thing through the ALIGN_UP macro
thus eliminating l_entries[0] from the structure. In this way we can
pacify the warning as l_hash[0] now becomes the last member to the
enclosed structure.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html

Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-03-31 12:17:03 +02:00
Peter Jones
9b89b1dedb efi: Fix the type of grub_efi_status_t
Currently, in some builds with some checkers, we see:

1. grub-core/disk/efi/efidisk.c:601: error[shiftTooManyBitsSigned]: Shifting signed 64-bit value by 63 bits is undefined behaviour

This is because grub_efi_status_t is defined as grub_efi_intn_t, which is
signed, and shifting into the sign bit is not defined behavior.  UEFI fixed
this in the spec in 2.3:

2.3 | Change the defined type of EFI_STATUS from INTN to UINTN | May 7, 2009

And the current EDK2 code has:
MdePkg/Include/Base.h-//
MdePkg/Include/Base.h-// Status codes common to all execution phases
MdePkg/Include/Base.h-//
MdePkg/Include/Base.h:typedef UINTN RETURN_STATUS;
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-/**
MdePkg/Include/Base.h-  Produces a RETURN_STATUS code with the highest bit set.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  @param  StatusCode    The status code value to convert into a warning code.
MdePkg/Include/Base.h-                        StatusCode must be in the range 0x00000000..0x7FFFFFFF.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  @return The value specified by StatusCode with the highest bit set.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-**/
MdePkg/Include/Base.h-#define ENCODE_ERROR(StatusCode)     ((RETURN_STATUS)(MAX_BIT | (StatusCode)))
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-/**
MdePkg/Include/Base.h-  Produces a RETURN_STATUS code with the highest bit clear.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  @param  StatusCode    The status code value to convert into a warning code.
MdePkg/Include/Base.h-                        StatusCode must be in the range 0x00000000..0x7FFFFFFF.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  @return The value specified by StatusCode with the highest bit clear.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-**/
MdePkg/Include/Base.h-#define ENCODE_WARNING(StatusCode)   ((RETURN_STATUS)(StatusCode))
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-/**
MdePkg/Include/Base.h-  Returns TRUE if a specified RETURN_STATUS code is an error code.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  This function returns TRUE if StatusCode has the high bit set.  Otherwise, FALSE is returned.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  @param  StatusCode    The status code value to evaluate.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  @retval TRUE          The high bit of StatusCode is set.
MdePkg/Include/Base.h-  @retval FALSE         The high bit of StatusCode is clear.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-**/
MdePkg/Include/Base.h-#define RETURN_ERROR(StatusCode)     (((INTN)(RETURN_STATUS)(StatusCode)) < 0)
...
Uefi/UefiBaseType.h:typedef RETURN_STATUS             EFI_STATUS;

This patch makes grub's implementation match the Edk2 declaration with regards
to the signedness of the type.

Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-03-10 21:42:31 +01:00
Alexander Graf
e642c95ab6 efi/gop: Add support for BLT_ONLY adapters
EFI GOP has support for multiple different bitness types of frame buffers
and for a special "BLT only" type which is always defined to be RGBx.

Because grub2 doesn't ever directly access the frame buffer but instead
only renders graphics via the BLT interface anyway, we can easily support
these adapters.

The reason this has come up now is the emerging support for virtio-gpu
in OVMF. That adapter does not have the notion of a memory mapped frame
buffer and thus is BLT only.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-03-10 21:40:31 +01:00
Peter Jones
8d88ae92b5 kern: Add grub_debug_enabled()
Add a grub_debug_enabled() helper function instead of open coding it.

Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-03-10 21:40:06 +01:00
Peter Jones
d5a32255de misc: Make grub_strtol() "end" pointers have safer const qualifiers
Currently the string functions grub_strtol(), grub_strtoul(), and
grub_strtoull() don't declare the "end" pointer in such a way as to
require the pointer itself or the character array to be immutable to the
implementation, nor does the C standard do so in its similar functions,
though it does require us not to change any of it.

The typical declarations of these functions follow this pattern:

long
strtol(const char * restrict nptr, char ** restrict endptr, int base);

Much of the reason for this is historic, and a discussion of that
follows below, after the explanation of this change.  (GRUB currently
does not include the "restrict" qualifiers, and we name the arguments a
bit differently.)

The implementation is semantically required to treat the character array
as immutable, but such accidental modifications aren't stopped by the
compiler, and the semantics for both the callers and the implementation
of these functions are sometimes also helped by adding that requirement.

This patch changes these declarations to follow this pattern instead:

long
strtol(const char * restrict nptr,
       const char ** const restrict endptr,
       int base);

This means that if any modification to these functions accidentally
introduces either an errant modification to the underlying character
array, or an accidental assignment to endptr rather than *endptr, the
compiler should generate an error.  (The two uses of "restrict" in this
case basically mean strtol() isn't allowed to modify the character array
by going through *endptr, and endptr isn't allowed to point inside the
array.)

It also means the typical use case changes to:

  char *s = ...;
  const char *end;
  long l;

  l = strtol(s, &end, 10);

Or even:

  const char *p = str;
  while (p && *p) {
	  long l = strtol(p, &p, 10);
	  ...
  }

This fixes 26 places where we discard our attempts at treating the data
safely by doing:

  const char *p = str;
  long l;

  l = strtol(p, (char **)&ptr, 10);

It also adds 5 places where we do:

  char *p = str;
  while (p && *p) {
	  long l = strtol(p, (const char ** const)&p, 10);
	  ...
	  /* more calls that need p not to be pointer-to-const */
  }

While moderately distasteful, this is a better problem to have.

With one minor exception, I have tested that all of this compiles
without relevant warnings or errors, and that /much/ of it behaves
correctly, with gcc 9 using 'gcc -W -Wall -Wextra'.  The one exception
is the changes in grub-core/osdep/aros/hostdisk.c , which I have no idea
how to build.

Because the C standard defined type-qualifiers in a way that can be
confusing, in the past there's been a slow but fairly regular stream of
churn within our patches, which add and remove the const qualifier in many
of the users of these functions.  This change should help avoid that in
the future, and in order to help ensure this, I've added an explanation
in misc.h so that when someone does get a compiler warning about a type
error, they have the fix at hand.

The reason we don't have "const" in these calls in the standard is
purely anachronistic: C78 (de facto) did not have type qualifiers in the
syntax, and the "const" type qualifier was added for C89 (I think; it
may have been later).  strtol() appears to date from 4.3BSD in 1986,
which means it could not be added to those functions in the standard
without breaking compatibility, which is usually avoided.

The syntax chosen for type qualifiers is what has led to the churn
regarding usage of const, and is especially confusing on string
functions due to the lack of a string type.  Quoting from C99, the
syntax is:

 declarator:
  pointer[opt] direct-declarator
 direct-declarator:
  identifier
  ( declarator )
  direct-declarator [ type-qualifier-list[opt] assignment-expression[opt] ]
  ...
  direct-declarator [ type-qualifier-list[opt] * ]
  ...
 pointer:
  * type-qualifier-list[opt]
  * type-qualifier-list[opt] pointer
 type-qualifier-list:
  type-qualifier
  type-qualifier-list type-qualifier
 ...
 type-qualifier:
  const
  restrict
  volatile

So the examples go like:

const char foo;			// immutable object
const char *foo;		// mutable pointer to object
char * const foo;		// immutable pointer to mutable object
const char * const foo;		// immutable pointer to immutable object
const char const * const foo; 	// XXX extra const keyword in the middle
const char * const * const foo; // immutable pointer to immutable
				//   pointer to immutable object
const char ** const foo;	// immutable pointer to mutable pointer
				//   to immutable object

Making const left-associative for * and right-associative for everything
else may not have been the best choice ever, but here we are, and the
inevitable result is people using trying to use const (as they should!),
putting it at the wrong place, fighting with the compiler for a bit, and
then either removing it or typecasting something in a bad way.  I won't
go into describing restrict, but its syntax has exactly the same issue
as with const.

Anyway, the last example above actually represents the *behavior* that's
required of strtol()-like functions, so that's our choice for the "end"
pointer.

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-02-28 12:41:29 +01:00
Peter Jones
03e72830ab grub-editenv: Add grub_util_readlink()
Currently grub-editenv and related tools are not able to follow symbolic
links when finding their config file. For example the grub-editenv create
command will wrongly overwrite a symlink in /boot/grub2/grubenv with a new
regular file, instead of creating a file in the path the symlink points to.

A following patch will change that and add support in grub-editenv to
follow symbolic links when finding the grub environment variables file.

Add a grub_util_readlink() helper function that is just a wrapper around
the platform specific function to read the value of a symbolic link. This
helper function will be used by the following patch for grub-editenv.

The helper function is not added for Windows, since this operating system
doesn't have a primitive to read the contents of a symbolic link.

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-02-18 15:14:13 +01:00
Paulo Flabiano Smorigo
cb2f15c544 normal/main: Search for specific config files for netboot
This patch implements a search for a specific configuration when the config
file is on a remoteserver. It uses the following order:
   1) DHCP client UUID option.
   2) MAC address (in lower case hexadecimal with dash separators);
   3) IP (in upper case hexadecimal) or IPv6;
   4) The original grub.cfg file.

This procedure is similar to what is used by pxelinux and yaboot:
http://www.syslinux.org/wiki/index.php/PXELINUX#config

It is enabled by default but can be disabled by setting the environment
variable "feature_net_search_cfg" to "n" in an embedded configuration.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=873406

Signed-off-by: Paulo Flabiano Smorigo <pfsmorigo@br.ibm.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-02-18 15:12:06 +01:00
Paulo Flabiano Smorigo
febc761e67 net/dhcp: Set net_<interface>_client{id, uuid} variables from DHCP options
This patch sets a net_<interface>_clientid and net_<interface>_clientuuid
GRUB environment variables, using the DHCP client ID and UUID options if
these are found.

In the same way than net_<interface>_<option> variables are set for other
options such domain name, boot file, next server, etc.

Signed-off-by: Paulo Flabiano Smorigo <pfsmorigo@br.ibm.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-02-18 15:12:06 +01:00