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>
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>
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>
The function that searches the mods section base address does not have
any debug information. Add some debugging outputs that could be useful.
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>
The address of fp->path_name could be unaligned since seeking into the
device path buffer for a given node could end in byte boundary.
The fix is allocating aligned buffer by grub_malloc for holding the
UTF16 string copied from fp->path_name, and after using that buffer as
argument for grub_utf16_to_utf8 to convert it to UTF8 string.
[ 255s] ../../grub-core/kern/efi/efi.c: In function 'grub_efi_get_filename':
[ 255s] ../../grub-core/kern/efi/efi.c:410:60: error: taking address of packed member of 'struct grub_efi_file_path_device_path' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[ 255s] 410 | p = (char *) grub_utf16_to_utf8 ((unsigned char *) p, fp->path_name, len);
[ 255s] | ~~^~~~~~~~~~~
[ 255s] ../../grub-core/kern/efi/efi.c: In function 'grub_efi_print_device_path':
[ 255s] ../../grub-core/kern/efi/efi.c:900:33: error: taking address of packed member of 'struct grub_efi_file_path_device_path' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[ 255s] 900 | *grub_utf16_to_utf8 (buf, fp->path_name,
[ 255s] | ~~^~~~~~~~~~~
Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The UEFI specification allows LoadImage() to be called with a memory
location only and without a device path. In this case FilePath will not be
set in the EFI_LOADED_IMAGE_PROTOCOL.
So in function grub_efi_get_filename() the device path argument may be
NULL. As we cannot determine the device path in this case just return NULL
from the function.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The reboot function calls machine_fini() and then reboots the system.
Currently it lives in lib/ which means it gets compiled into the
reboot module which lives on the heap.
In a following patch, I want to free the heap on machine_fini()
though, so we would free the memory that the code is running in. That
obviously breaks with smarter UEFI implementations.
So this patch moves it into the core. That way we ensure that all
code running after machine_fini() in the UEFI case is running from
memory that got allocated (and gets deallocated) by the UEFI core.
Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
UEFI 2.6 9.3.6.4 File Path Media Device Path says that Path Name is
"A NULL-terminated Path string including directory and file names".
Strip final NULL from Path Name in each File Path node when constructing
full path. To be on safe side, strip all of them.
Fixes failure chainloading grub from grub, when loaded grub truncates
image path and does not find its grub.cfg.
https://bugzilla.opensuse.org/show_bug.cgi?id=1026344
This was triggered by commit ce95549cc54b5d6f494608a7c390dba3aab4fba7;
before it we built Path Name without trailing NULL, and apparently all
other bootloaders use single File Path node, thus not exposing this bug.
The current code for EFI grub_exit() calls grub_efi_fini() before
returning to firmware. In the case of ARM, this leaves a timer
event running which could lead to a firmware crash. This patch
changes this so that grub_machine_fini() is called with a NORETURN
flag. This allows machine-specific shutdown to happen as well
as the shutdown done by grub_efi_fini().
Signed-off-by: Mark Salter <msalter@redhat.com>
* grub-core/commands/efi/efifwsetup.c: New file.
* grub-core/kern/efi/efi.c (grub_efi_set_variable): New function
* include/grub/efi/api.h (GRUB_EFI_OS_INDICATIONS_BOOT_TO_FW_UI):
New define.
* include/grub/efi/efi.h (grub_efi_set_variable): New proto.
* grub-core/kern/efi/efi.c (grub_rtc_get_time_ms) [__ia64__]: Remove on
ia64.
(grub_get_rtc) [__ia64__]: Likewise.
* grub-core/kern/ia64/efi/init.c (divisor): New variable.
(get_itc): New function.
(grub_rtc_get_time_ms): Likewise.
(grub_machine_init): Calibrate ITC.
* include/grub/efi/time.h (grub_get_rtc), (GRUB_TICKS_PER_SECOND):
Keep only on non-ia64. Don't export since it's broken and used only
if TSC is unavailable.
* grub-core/kern/efi/efi.c (grub_efi_get_variable): New argument
datasize_out.
* grub-core/video/efi_gop.c (check_protocol): Check that GOP has usable
modes. Set gop_handle.
(grub_video_gop_get_edid): New function.
(grub_gop_get_preferred_mode): Likewise.
(grub_video_gop_setup): Use grub_gop_get_preferred_mode.
(grub_video_efi_gop_adapter): Set .get_edid.
* include/grub/efi/edid.h: New file.
* include/grub/efi/efi.h (grub_efi_get_variable): Update proto.
Also-By: Vladimir Serbinenko <phcoder@gmail.com>
