Some EFI systems fail to boot in efi_init() when booted via maas
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Fix Released
|
High
|
Andy Whitcroft | ||
Bionic |
Fix Released
|
High
|
Andy Whitcroft | ||
Disco |
Fix Released
|
High
|
Andy Whitcroft | ||
Eoan |
Fix Released
|
High
|
Andy Whitcroft | ||
Focal |
Fix Released
|
High
|
Andy Whitcroft |
Bug Description
[Impact]
Cirtain EFI systems will no longer boot with updated versions of maas. They will still boot in BIOS compatibility mode where available.
[Test Case]
Affected systems have already been tested with this fix applied and now boot successfully in EFI mode. The key test is does any EFI based system boot with this applied.
[Regression Potential]
The change increased the headroom by a very small amount, an additional 8 slots. This is very unlikely to lead to additional failures.
===
When booting via newer versions of maas we use grub extensions to load additional files. This leads the kernel to panic in efi_main():
exit_boot() failed!
efi_main() failed!
This occurs because the EFI memory map is more fragmented. When we exit boot services that returns an updated memory map in a buffer we supply. This has to be large enough to contain the updated map. If the exit fails because of lack of map space we are dead in the water because the call to allocate memory is lost to us. We therefore add some headroom in the allocation to allow for any expansion during close. This headroom is insufficient.
CVE References
Changed in linux (Ubuntu): | |
status: | New → In Progress |
importance: | Undecided → High |
assignee: | nobody → Andy Whitcroft (apw) |
description: | updated |
Changed in linux (Ubuntu Eoan): | |
status: | New → In Progress |
Changed in linux (Ubuntu Disco): | |
status: | New → In Progress |
Changed in linux (Ubuntu Bionic): | |
status: | New → In Progress |
importance: | Undecided → High |
Changed in linux (Ubuntu Disco): | |
importance: | Undecided → Critical |
importance: | Critical → High |
Changed in linux (Ubuntu Eoan): | |
importance: | Undecided → High |
assignee: | nobody → Andy Whitcroft (apw) |
Changed in linux (Ubuntu Disco): | |
assignee: | nobody → Andy Whitcroft (apw) |
Changed in linux (Ubuntu Bionic): | |
assignee: | nobody → Andy Whitcroft (apw) |
Changed in linux (Ubuntu Eoan): | |
status: | In Progress → Fix Committed |
Changed in linux (Ubuntu Disco): | |
status: | In Progress → Fix Committed |
Changed in linux (Ubuntu Bionic): | |
status: | In Progress → Fix Committed |
This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification- needed- eoan' to 'verification- done-eoan' . If the problem still exists, change the tag 'verification- needed- eoan' to 'verification- failed- eoan'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.
See https:/ /wiki.ubuntu. com/Testing/ EnableProposed for documentation how to enable and use -proposed. Thank you!