Re: [PATCH rdma-next v3] RDMA/mana_ib: Clamp adapter capabilities at the ib_device_attr boundary

[Erni Sri Satya Vennela]

On Thu, Jun 11, 2026 at 02:17:45PM +0300, Leon Romanovsky wrote:
> On Mon, May 25, 2026 at 12:01:01PM -0700, Erni Sri Satya Vennela wrote:
> > mana_ib stores its adapter capabilities internally as u32 in
> > struct mana_ib_adapter_caps. The IB core, however, exposes the
> > corresponding device attributes through struct ib_device_attr, where
> > fields such as max_qp, max_qp_wr, max_send_sge, max_recv_sge,
> > max_sge_rd, max_cq, max_cqe, max_mr, max_pd, max_qp_rd_atom,
> > max_res_rd_atom and max_qp_init_rd_atom are signed int.
> > 
> > mana_ib_query_device() is the only place that copies the cached u32
> > caps into these int fields. If a cap exceeds INT_MAX, the implicit
> > u32-to-int narrowing yields a negative value. Clamp each cap to
> > INT_MAX at this boundary so the values handed to the IB core are always
> > non-negative.
> > 
> > While here, fix a related overflow in the computation of
> > max_res_rd_atom. It is derived as max_qp_rd_atom * max_qp, both of
> > which are int after the assignment above; the multiplication can
> > overflow an int even with the new clamps in place. Widen to s64
> > before multiplying and clamp the result to INT_MAX.
> > 
> > Signed-off-by: Erni Sri Satya Vennela <ernis@xxxxxxxxxxxxxxxxxxx>
> > ---
> > Changes in v3:
> > * Drop clamping from mana_ib_gd_query_adapter_caps(). The internal u32
> >   caps cache does not need to be clamped.
> > * Move all clamping exclusively to mana_ib_query_device(), which is the
> >   only place the cached u32 values are narrowed into the signed int
> >   fields of struct ib_device_attr.
> > * Reframe commit message: this is a u32-to-int type boundary fix, not a
> >   CVM/untrusted-hardware hardening patch.
> 
> You should align all types to u32 and avoid hiding the issue behind  
> min_t().
> 
> Thanks
Yes Leon, I'm currently at v7 version of this patch.
I'm planning to completely avoid using min_t in the next version.

- Vennela