[PATCH] nvme: nvme_identify_ns_descs: prevent oob

[Christoph Hellwig]

On Wed, Nov 26, 2025 at 01:52:08PM -0700, Keith Busch wrote:
> On Wed, Nov 26, 2025 at 11:27:21PM +0300, Eugene Korenevsky wrote:
> > Broken or malicious controller can send invalid ns id.
> > Out-of-band memory access may occur if remaining buffer size
> > is less than .nidl (ns id length) field of `struct nvme_ns_id_desc`
> > 
> > Fix this issue by making nvme_process_id_decs() function aware of
> > remaining buffer size.
> > 
> > Also simplify nvme_process_id_decs(): replace copy-pasted `case`
> > branches with table lookup.
> > 
> > Signed-off-by: Eugene Korenevsky <ekorenevsky at aliyun.com>
> > ---
> >  drivers/nvme/host/core.c | 80 ++++++++++++++++++++--------------------
> >  1 file changed, 39 insertions(+), 41 deletions(-)
> 
> Is this simpler check not sufficient?

I think we'll need a somewhat more complex check that at there
is at least enough space for the len member.  But I prefer that
style over a table lookup and magic name pasting macros.