Linux 4.5-rc5: efivarfs fixed to avoid “rm -rf /” bricking UEFI

(git.kernel.org)

279 points the_why_of_y | 1 comments | 22 Feb 16 18:08 UTC | HN request time: 0.251s | source

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Mic92 ◴[22 Feb 16 19:16 UTC] No.11153454[source]▶

Instead of flaming systemd developers for mounting efivars read/write, the kernel is the right place to fix the problem for everybody!

replies(1): >>11153544 #

ajross ◴[22 Feb 16 19:28 UTC] No.11153544[source]▶

>>11153454 #

No, the firmware is the right place to fix the problem. A BIOS that bricks itself because of within-specification deletion of variables via a standard API is just plain broken.

But in the real world no one ever fixes firmware bugs, so this is the best we can do.

replies(3): >>11153652 #>>11153744 #>>11153940 #

1. captainmuon ◴[22 Feb 16 19:55 UTC] No.11153744[source]▶

>>11153544 #

Bricking is a rather extreme firmware bug, but even if it didn't brick itself - if it just lost a bunch of information (Boot list, Vendor information, Time, BIOS settings, Windows activation data / preinstalled keys... I don't know all the kinds of stuff you can put in there.)... wouldn't that also be bad? I would never expect to be able to cause that by deleting a directory. So by the principle of least surprise, this shouldn't be mounted by default.

So on a non-broken BIOS, there is "technically" no bug - but the pieces (BIOS, Kernel, Systemd) come together to make a bad design.

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