It seems some older versions of libefi var incorrectly build the 'length' value
in the DP returned from efi_generate_file_device_path(). This means we copy past
the end of the allocated buffer when parsing the efi_update_info_t structure.
This bug seems fixed in efivar git master, and this fix is only going to help
people with older efivar versions. It's probably a good thing to be a bit more
paranoid about EFI variable data anyway.
DEBUG: UpdateInfo:
? 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
????????????????????????????????????????????????????????????????????????????????????????????????????????
0x0000 ? 07 00 00 00 20 d9 7b 69 cf 12 a9 4d 83 85 99 69 09 bc 65 59 00 00 05 00 00 00 00 00 00 00 00 00
0x0020 ? 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 04 01 2a 00 01 00 00 00 00 08 00 00
0x0040 ? 00 00 00 00 00 40 06 00 00 00 00 00 5a aa 97 5a 10 d5 7e 49 99 0b ca 8d 35 4d c8 6d 02 02 04 04
0x0060 ? 86 00 5c 00 45 00 46 00 49 00 5c 00 66 00 65 00 64 00 6f 00 72 00 61 00 5c 00 66 00 77 00 5c 00
0x0080 ? 66 00 77 00 75 00 70 00 64 00 2d 00 36 00 39 00 37 00 62 00 64 00 39 00 32 00 30 00 2d 00 31 00
0x00a0 ? 32 00 63 00 66 00 2d 00 34 00 64 00 61 00 39 00 2d 00 38 00 33 00 38 00 35 00 2d 00 39 00 39 00
0x00c0 ? 36 00 39 00 30 00 39 00 62 00 63 00 36 00 35 00 35 00 39 00 2e 00 63 00 61 00 70 00 00 00 7f ff
0x00e0 ? 04 00
DEBUG: DP type:0x04 subtype:0x01 size:0x002a
DEBUG: DP type:0x04 subtype:0x04 size:0x0086
DEBUG: found END_ENTIRE at 0x00aa
DEBUG: DP length invalid! Truncating from 0x0086 to 0x0080
DEBUG: DP type:0x7f subtype:0xff size:0x0004
|
||
|---|---|---|
| .. | ||
| efi | ||
| tests | ||
| fu-plugin-uefi.c | ||
| fu-self-test.c | ||
| fu-ucs2.c | ||
| fu-ucs2.h | ||
| fu-uefi-bgrt.c | ||
| fu-uefi-bgrt.h | ||
| fu-uefi-bootmgr.c | ||
| fu-uefi-bootmgr.h | ||
| fu-uefi-common.c | ||
| fu-uefi-common.h | ||
| fu-uefi-device.c | ||
| fu-uefi-device.h | ||
| fu-uefi-devpath.c | ||
| fu-uefi-devpath.h | ||
| fu-uefi-pcrs.c | ||
| fu-uefi-pcrs.h | ||
| fu-uefi-tool.c | ||
| fu-uefi-update-info.c | ||
| fu-uefi-update-info.h | ||
| fu-uefi-vars.c | ||
| fu-uefi-vars.h | ||
| meson.build | ||
| README.md | ||
| uefi.conf | ||
| uefi.quirk | ||
UEFI Support
Introduction
The Unified Extensible Firmware Interface (UEFI) is a specification that defines the software interface between an OS and platform firmware. With the UpdateCapsule boot service it can be used to update system firmware.
If you don't want or need this functionality you can use the
-Dplugin_uefi=false option.
Firmware Format
The daemon will decompress the cabinet archive and extract a firmware blob in EFI capsule file format.
See https://www.uefi.org/sites/default/files/resources/UEFI%20Spec%202_6.pdf for details.
This plugin supports the following protocol ID:
- org.uefi.capsule
GUID Generation
These devices use the UEFI GUID as provided in the ESRT. Additionally, for the
system device the main-system-firmware GUID is also added.
For compatibility with Windows 10, the plugin also adds GUIDs of the form
UEFI\RES_{$(esrt)}.
UEFI Unlock Support
On some Dell systems it is possible to turn on and off UEFI capsule support from within the BIOS. This functionality can also be adjusted from within the OS by fwupd. This requires compiling with libsmbios support.
When fwupd has been compiled with this support you will be able to enable UEFI
support on the device by using the unlock command.
Custom EFI System Partition
Since version 1.1.0 fwupd will autodetect the ESP when it is mounted on
/boot/efi, /boot, or /efi. A custom EFI system partition location can be
used by modifying OverrideESPMountPoint in /etc/fwupd/uefi.conf.
Setting an invalid directory will disable the fwupd plugin.