Re: [PATCH] block: don't overwrite bip_vcnt in bio_integrity_copy_user()

[Christoph Hellwig]

On Mon, May 11, 2026 at 10:51:51PM +0100, David Carlier wrote:
> bio_integrity_add_page() already sets bip_vcnt to 1 for the bounce
> segment. Overwriting it with nr_vecs breaks bip_vcnt <= bip_max_vcnt
> on WRITE (bip_max_vcnt is 1), so the gap-merge checks in block/blk.h
> read past the bip_vec[] flex array. On READ the read is in bounds
> but lands on a saved user bvec instead of the bounce.
> 
> The line was added for split propagation, but bio_integrity_clone()
> doesn't copy bip_vcnt and BIP_CLONE_FLAGS excludes BIP_COPY_USER.

Looks good:

Reviewed-by: Christoph Hellwig <hch@xxxxxx>