Add infrastructure to allow firmware to verify the integrity of GRUB
by use of a Linux-kernel-module-style appended signature. We initially
target powerpc-ieee1275, but the code should be extensible to other
platforms.
Usually these signatures are appended to a file without modifying the
ELF file itself. (This is what the 'sign-file' tool does, for example.)
The verifier loads the signed file from the file system and looks at the
end of the file for the appended signature. However, on powerpc-ieee1275
platforms, the bootloader is often stored directly in the PReP partition
as raw bytes without a file-system. This makes determining the location
of an appended signature more difficult.
To address this, we add a new ELF Note.
The name field of shall be the string "Appended-Signature", zero-padded
to 4 byte alignment. The type field shall be 0x41536967 (the ASCII values
for the string "ASig"). It must be the final section in the ELF binary.
The description shall contain the appended signature structure as defined
by the Linux kernel. The description will also be padded to be a multiple
of 4 bytes. The padding shall be added before the appended signature
structure (not at the end) so that the final bytes of a signed ELF file
are the appended signature magic.
A subsequent patch documents how to create a GRUB core.img validly signed
under this scheme.
Signed-off-by: Rashmica Gupta <rashmica.g@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Avnish Chouhan <avnish@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
When using grub-mkrescue for a riscv32 target, an invalid implicit cast
on the offset calculation produces an error during the relocation process:
grub-mkrescue: error: target XXX not reachable from pc=fc.
This patch adds an explicit grub_int64_t cast to compute the offset
as a 64-bit subtraction.
Signed-off-by: Anaëlle Cazuc <acazuc@acazuc.fr>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
In order to store the SBAT data we create a new ELF note. The string
".sbat", zero-padded to 4 byte alignment, shall be entered in the name
field. The string "SBAT"'s ASCII values, 0x53424154, should be entered
in the type field.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Assembly code looks for modules at __bss_start. Make this position explicit
rather than matching BSS alignment and module alignment.
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
According to the relocation documentation, the following function names are
renamed to show their exact meaning:
- from grub_loongarch64_xxx64_hi12() to grub_loongarch64_abs64_hi12(),
- from grub_loongarch64_xxx64_hi12() to grub_loongarch64_abs64_lo20().
Signed-off-by: Xiaotian Wu <wuxiaotian@loongson.cn>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
We already have the pc variable, no need to calculate it again.
Signed-off-by: Xiaotian Wu <wuxiaotian@loongson.cn>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
A new set of relocation types was added in the LoongArch ELF psABI v2.00
spec [1], [2] to replace the stack-based scheme in v1.00. Toolchain
support is available from binutils 2.40 and gcc 13 onwards.
This patch adds support for the new relocation types, that are simpler
to handle (in particular, stack operations are gone). Support for the
v1.00 relocs are kept for now, for compatibility with older toolchains.
[1] https://github.com/loongson/LoongArch-Documentation/pull/57
[2] https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html#_appendix_revision_history
Signed-off-by: Xiaotian Wu <wuxiaotian@loongson.cn>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This patch adds support of the stack-based LoongArch relocations
throughout GRUB, including tools, dynamic linkage, and support for
conversion of ELF relocations into PE ones. A stack machine is required
to handle these per the spec [1] (see the R_LARCH_SOP types), of which
a simple implementation is included.
These relocations are produced by binutils 2.38 and 2.39, while the newer
v2.00 relocs require more recent toolchain (binutils 2.40+ & gcc 13+, or
LLVM 16+). GCC 13 has not been officially released as of early 2023, so
support for v1.00 relocs are expected to stay relevant for a while.
[1] https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html#_relocations
Signed-off-by: Zhou Yang <zhouyang@loongson.cn>
Signed-off-by: Xiaotian Wu <wuxiaotian@loongson.cn>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
A recent fix that made appears to have broken the ability to create an
aarch64 boot image on a x86-based host.
This was due to an overzealous testing of the architecture when building
grub-mkimage and removing the code that build an ARM image when not built
on ARM.
On the occasion remove redundant break.
Fixes: 8541f319 (grub-mkimage: Only check aarch64 relocations when built for aarch64)
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Tested-by: Selva Ganesan <selvaganesan89@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Coverity flagged the switch checks for R_AARCH64_* as being logically
dead code, since it could never happen on x86 due to the masking of the
values earlier in the code.
A check for building on __arm__ (which gcc and clang define) and for
MKIMAGE_ELF64 (which GRUB defines) has been added to avoid this dead
code being built in.
Fixes: CID 158599
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The commit f60ba9e5945 (util/mkimage: Refactor section setup to use a helper)
added a helper function to setup PE sections. But it also changed how the
raw data offsets were calculated since all the section sizes are aligned.
However, for some platforms, i.e ia64-efi and arm64-efi, the kernel image
size is not aligned using the section alignment. This leads to the situation
in which the mods section offset in its PE section header does not match its
real placement in the PE file. So, finally the GRUB is not able to locate
and load built-in modules.
The problem surfaces on ia64-efi and arm64-efi because both platforms
require additional relocation data which is added behind .bss section.
So, we have to add some padding behind this extra data to make the
beginning of mods section properly aligned in the PE file. Fix it by
aligning the kernel_size to the section alignment. That makes the sizes
and offsets in the PE section headers to match relevant sections in the
PE32+ binary file.
Reported-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
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>
Currently, an image generated with 'grub-mkimage -n' causes an error when
read with 'readelf -a':
Displaying notes found at file offset 0x000106f0 with length 0x0000002c:
Owner Data size Description
readelf: Warning: note with invalid namesz and/or descsz found at offset 0x0
readelf: Warning: type: 0x1275, namesize: 0x00000008, descsize: 0x0000002c, alignment: 4
This is because the descsz of the CHRP note is set to
sizeof (struct grub_ieee1275_note)
which is the size of the entire note, including name and elf header. The
desczs should contain only the contents, not the name and header sizes.
Set the descsz instead to 'sizeof (struct grub_ieee1275_note_desc)'
Resultant readelf output:
Displaying notes found at file offset 0x00010710 with length 0x0000002c:
Owner Data size Description
PowerPC 0x00000018 Unknown note type: (0x00001275)
description data: ff ff ff ff 00 c0 00 00 ff ff ff ff ff ff ff ff ff ff ff ff 00 00 40 00
So far as I can tell this issue has existed for as long as the note
generation code has existed, but I guess nothing really checks descsz.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The offset calculation was missing the relocation addend.
Signed-off-by: Andreas Schwab <schwab@suse.de>
Tested-by: Chester Lin <clin@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The arm relocation code has a manual special case for EFI binaries to
add the natural alignment to its own relocation awareness.
Since commit a51f953f4ee87 ("mkimage: Align efi sections on 4k
boundary") we changed that alignment from 0x400 to 0x1000 bytes. Reflect
the change in that branch that we forgot as well.
This fixes running 32bit arm grub efi binaries for me again.
Fixes: a51f953f4ee87 ("mkimage: Align efi sections on 4k boundary")
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reported-by: Steve McIntyre <steve@einval.com>
Signed-off-by: Alexander Graf <agraf@csgraf.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Julien ROBIN <julien.robin28@free.fr>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
When creating T32->A32 transition jumps, the relocation code in grub
will generate trampolines. These trampolines live in the .data section
of our PE binary which means they are not marked as executable.
This misbehavior was unmasked by commit a51f953f4ee87 ("mkimage: Align
efi sections on 4k boundary") which made the X/NX boundary more obvious
because everything became page aligned.
To put things into proper order, let's move the arm trampolines into the
.text section instead. That way everyone knows they are executable.
Fixes: a51f953f4ee87 ("mkimage: Align efi sections on 4k boundary")
Reported-by: Julien ROBIN <julien.robin28@free.fr>
Reported-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Alexander Graf <agraf@csgraf.de>
Tested-by: Julien ROBIN <julien.robin28@free.fr>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This patch adds awareness of RISC-V relocations throughout the grub tools
as well as dynamic linkage and elf->PE relocation conversion support.
Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Support mkimage for xen_pvh.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Hans van Kranenburg <hans@knorrie.org>
In order to avoid using plain integers for the ELF notes use the
available Xen include instead.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Hans van Kranenburg <hans@knorrie.org>
The grub_mkimage_load_image function (commit 7542af6, mkimage: refactor a bunch
of section data into a struct.) introduces a build regression on SPARC:
cc1: warnings being treated as errors
In file included from util/grub-mkimage32.c:23:
util/grub-mkimagexx.c: In function 'grub_mkimage_load_image32':
util/grub-mkimagexx.c:1968: error: missing initializer
util/grub-mkimagexx.c:1968: error: (near initialization for 'smd.sections')
make[2]: *** [util/grub_mkimage-grub-mkimage32.o] Error 1
Initialize the entire section_metadata structure.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Some versions of gcc include a plugin called "annobin", and in some
build systems this is enabled by default. This plugin creates special
ELF note sections to track which ABI-breaking features are used by a
binary, as well as a series of relocations to annotate where.
If grub is compiled with this feature, then when grub-mkimage translates
the binary to another file format which does not strongly associate
relocation data with sections (i.e. when platform is *-efi), these
relocations appear to be against the .text section rather than the
original note section. When the binary is loaded by the PE runtime
loader, hilarity ensues.
This issue is not necessarily limited to the annobin, but could arise
any time there are relocations in sections that are not represented in
grub-mkimage's output.
This patch seeks to avoid this issue by only including relocations that
refer to sections which will be included in the final binary.
As an aside, this should also obviate the need to avoid -funwind-tables,
-fasynchronous-unwind-tables, and any sections similar to .eh_frame in
the future. I've tested it on x86-64-efi with the following gcc command
line options (as recorded by -grecord-gcc-flags), but I still need to
test the result on some other platforms that have been problematic in
the past (especially ARM Aarch64) before I feel comfortable making
changes to the configure.ac bits:
GNU C11 7.2.1 20180116 (Red Hat 7.2.1-7) -mno-mmx -mno-sse -mno-sse2 -mno-sse3 -mno-3dnow -msoft-float -mno-stack-arg-probe -mcmodel=large -mno-red-zone -m64 -mtune=generic -march=x86-64 -g3 -Os -freg-struct-return -fno-stack-protector -ffreestanding -funwind-tables -fasynchronous-unwind-tables -fno-strict-aliasing -fstack-clash-protection -fno-ident -fplugin=annobin
Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This basically moves a bunch of the section information we pass around a
lot into a struct, and passes a pointer to a single one of those
instead.
This shouldn't change the binary file output or the "grub-mkimage -v"
output in any way.
Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This puts both kinds of address initialization at the same place, and also lets
us iterate through the section list one time fewer.
Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This renames some things:
- the "strtab" and "strtab_section" in relocate_symbols are changed to "symtab"
instead, so as to be less confusing when "strtab" is moved to a struct in a
later patch.
- The places where we pass section_vaddresses to functions are changed to also
be called section_vaddresses"inside those functions, so I get less confused
when I put addresses and vaddresses in a struct in a later patch.
Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This makes it so you can treat grub-mkimagexx.c as a file you can build
directly, so syntax checkers like vim's "syntastic" plugin, which uses
"gcc -x c -fsyntax-only" to build it, will work.
One still has to do whatever setup is required to make it pick the right
include dirs, which -W options we use, etc., but this makes it so you
can do the checking on the file you're editing, rather than on a
different file.
Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Starting from binutils commit bd7ab16b4537788ad53521c45469a1bdae84ad4a:
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=bd7ab16b4537788ad53521c45469a1bdae84ad4a
x86-64 assembler generates R_X86_64_PLT32, instead of R_X86_64_PC32, for
32-bit PC-relative branches. Grub2 should treat R_X86_64_PLT32 as
R_X86_64_PC32.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
In util/getroot and efidisk slightly modify exitsing comment to mostly
retain it but still make GCC7 compliant with respect to fall through
annotation.
In grub-core/lib/xzembed/xz_dec_lzma2.c it adds same comments as
upstream.
In grub-core/tests/setjmp_tets.c declare functions as "noreturn" to
suppress GCC7 warning.
In grub-core/gnulib/regexec.c use new __attribute__, because existing
annotation is not recognized by GCC7 parser (which requires that comment
immediately precedes case statement).
Otherwise add FALLTHROUGH comment.
Closes: 50598
According to EABI only STT_FUNC has convention of lowest bit indicating
execution mode. R_THM_{JUMP,CALL}* relocations are assumed to be pointing
to thumb mode unless they use STT_FUNC.
util/grub-mkimagexx.c is included in a special way into mkimage.c.
Interoperation between defines makes this very tricky. Instead
just have a clean interface and compile util/grub-mkimage*.c separately
from mkimage.c
This did not cause real problem but is good for reproducible builds. I hit
it with recent bootinfoscript that displays embedded config; I was puzzled
by random garbage at the end.
Prezero memory buffer used to assemble core.img. This makes individual
memset redundant. Also ensure buffer is filled with zeroes in several other
places.
Also remove redundant zeroing code where we fill in the whole memory block
anyway.
