Writing the primary GPT before the backup may lead to a confusing
situation: booting a freshly updated system could consistently fail and
next boot will fall back to the old system if writing the primary works
but writing the backup fails. If the backup is written first and fails
the primary is left in the old state so the next boot will re-try and
possibly fail in the exact same way. Making that repeatable should make
it easier for users to identify the error.
Additionally if the firmware and OS disagree on the disk size, making
the backup inaccessible to GRUB, then just skip writing the backup.
When this happens the automatic call to `coreos-setgoodroot` after boot
will take care of repairing the backup.
The firmware and the OS may disagree on the disk configuration and size.
Although such a setup should be avoided users are unlikely to know about
the problem, assuming everything behaves like the OS. Tolerate this as
best we can and trust the reported on-disk location over the firmware
when looking for the backup GPT. If the location is inaccessible report
the error as best we can and move on.
I personally think this reads easier. Also has the side effect of
directly comparing the primary and backup tables instead of presuming
they are equal if the crc32 matches.
This ensures all code modifying GPT data include the same sanity check
that repair does. If revalidation fails the status flags are left in the
appropriate state.
The header was being relocated without checking the new location is
actually safe. If the BIOS thinks the disk is smaller than the OS then
repair may relocate the header into allocated space, failing the final
validation check. So only move it if the disk has grown.
Additionally, if the backup is valid then we can assume its current
location is good enough and leave it as-is.
Use the new status function which checks *_HEADER_VALID and
*_ENTRIES_VALID bits together. It doesn't make sense for the header and
entries bits to mismatch so don't allow for it.
Portions of the code attempted to handle the fact that GPT entries on
disk may be larger than the currently defined struct while others
assumed the data could be indexed by the struct size directly. This
never came up because no utility uses a size larger than 128 bytes but
for the sake of safety we need to do this by the spec.
GPT_BOTH_VALID is 4 bits so simple a boolean check is not sufficient.
This broken condition allowed gptprio to trust bogus disk locations in
headers that were marked invalid causing arbitrary disk corruption.
GRUB assumes that no disk is ever larger than 1EiB and rejects
reads/writes to such locations. Unfortunately this is not conveyed in
the usual way with the special GRUB_DISK_SIZE_UNKNOWN value.
send client arch in bootp requests, for now BIOS and x64/aarch64 EFI is
supported.
fix a bug introduced in 4d5d7be005 where
user class was encoded improperly, although this didn't seem to have any
detrimental effects.
properly insert an option terminator.
Some DHCP servers (such as dnsmasq) tokenise parameters with commas, making
it impossible to pass boot files with commas in them. Allow using a semicolon
to separate the protocol from host if a comma wasn't found.
The current logic in the DNS resolution code allocates an address buffer
based on the number of addresses in the response packet. If we receive
multiple response packets in response to a single query packet, this means
that we will reallocate a new buffer large enough for only the addresses in
that specific packet, discarding any previous results in the process. Worse,
we still keep track of the *total* number of addresses resolved in response
to this query, not merely the number in the packet being currently processed.
Use realloc() rather than malloc() to avoid overwriting the existing data,
and allocate a buffer large enough for the total set of addresses rather
than merely the number in this specific response.
Rework TPM measurements to use fewer PCRs. After discussion with upstream,
it's preferable to avoid using so many PCRs. Instead, measure into PCRs 8
and 9 but use a prefix in the event log to indicate which subsystem carried
out the measurements.
It's helpful to determine that a request was sent by grub in order to permit
the server to provide different information at different stages of the boot
process. Send GRUB2 as a type 77 DHCP option when sending bootp packets in
order to make this possible.
Add support for adding gpg keys to the trusted database with a new command
called "trust_var". This takes the contents of a variable (in ascii-encoded
hex) and interprets it as a gpg public key.
The getenv code was mishandling the conversion of binary to hex. Grub's
sprintf() doesn't seem to support the full set of format conversions, so
fix this in the nasty way.
We want a single buffer that contains the entire kernel image in order to
perform a TPM measurement. Allocate one and copy the entire kernel int it
before pulling out the individual blocks later on.
We want a single buffer that contains the entire kernel image in order to
perform a TPM measurement. Allocate one and copy the entire kernel into it
before pulling out the individual blocks later on.
Add support for performing basic TPM measurements. Right now this only
supports extending PCRs statically and only on UEFI and BIOS systems, but
will measure all modules as they're loaded.
The Secure Boot code currently reads the kernel from disk, validates the
signature and then reads it from disk again. A sufficiently exciting storage
device could modify the kernel between these two events and trigger the
execution of an untrusted kernel. Avoid re-reading it in order to ensure
this isn't a problem, and in the process speed up boot by not reading the
kernel twice.
