Re: [PATCH RFC] blk-integrity: fix slab-out-of-bounds in t10_pi_verify on namespace revalidation

[Christoph Hellwig]

On Sun, May 31, 2026 at 06:45:07PM -0400, Samin Y. Chowdhury via B4 Relay wrote:
> When a namespace is revalidated between bio_integrity_prep() and
> bio_integrity_verify_fn(), the integrity profile's metadata_size may
> change under the in-flight bio. bio_integrity_verify_fn() re-reads the
> live blk_integrity via blk_get_integrity(), so blk_integrity_iterate()
> uses the new metadata_size as the per-interval step size against a
> buffer sized for the old one, advancing iter->prot_buf past the end of
> the allocation.

I don't think changing fundamental device properies such as the LBA
or integrity tag size under a live device is a good model.  So instead
of coming up with bandaids like this, we should probably just fail
any such revalidation when there are openers instead of trying to deal
with the fallout.