Re: bio_integrity_verify() bug causing READ verify to be silentlyskipped

From: Nicholas A. Bellinger
Date: Fri Jan 17 2014 - 00:19:12 EST


On Fri, 2014-01-03 at 15:09 -0500, Martin K. Petersen wrote:
> >>>>> "nab" == Nicholas A Bellinger <nab@xxxxxxxxxxxxxxx> writes:
>
> nab> Given that bio_integrity_verify() is using bio_for_each_segment(),
> nab> the loop starts from the updated bio->bi_idx, and not a zero value,
> nab> which ends up skipping individual bio segment calls to
> nab> bi->verify_fn().
>
> That's botched. Verify is meant to be called with the completed bytes
> before the index is tampered with.
>
>
> nab> The following patch changes bio_integrity_verify() to use
> nab> bio_for_each_segment_all() instead of bio_for_each_segment() to
> nab> ensure that the segment walk always starts from zero, regardless of
> nab> the current bio->bi_idx value after bio_advance().
>
> That breaks partial completion, though. I'll take a look at Kent's
> changes...
>

Ping..? Any updates on a proper bugfix for this..?

--nab

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