Re: [PATCH 1/1 v9] use crc32 instead of md5 for hibernation e820 integrity check

From: Eric Biggers
Date: Mon Apr 19 2021 - 18:16:57 EST


On Fri, Apr 16, 2021 at 09:16:55AM -0400, Chris von Recklinghausen wrote:
> Hibernation fails on a system in fips mode because md5 is used for the e820
> integrity check and is not available. Use crc32 instead.

Doesn't the commit title need to be prefixed with something like "x86/power"?

> The check is intended to detect whether the E820 memory map provided
> by the firmware after cold boot unexpectedly differs from the one that
> was in use when the hibernation image was created. In this case, the
> hibernation image cannot be restored, as it may cover memory regions
> that are no longer available to the OS.
>
> A non-cryptographic checksum such as CRC-32 is sufficient to detect such
> inadvertent deviations.
>
> Fixes: 62a03defeabd ("PM / hibernate: Verify the consistent of e820 memory map
> by md5 digest")

The "Fixes" line shouldn't be line-wrapped.

Otherwise this looks fine. The explanation in the commit message still isn't
great, but it's much better than it was before.

You can add:

Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>

- Eric