Subject: Re: [PATCH net-next v2] net: mana: Use at least SZ_4K in doorbell ID range check

From: Simon Horman <[email-masked]>
Date: Thu, 26 Mar 2026 20:07:40 +0000

On Wed, Mar 25, 2026 at 11:04:17AM -0700, Erni Sri Satya Vennela wrote:
> mana_gd_ring_doorbell() accesses offsets up to DOORBELL_OFFSET_EQ
> (0xFF8) + 8 bytes = 4KB within each doorbell page. A db_page_size
> smaller than SZ_4K is fundamentally incompatible with the driver:
> doorbell pages would overlap and the device cannot function correctly.
> 
> Validate db_page_size at the source and fail the
> probe early if the value is below SZ_4K. This ensures the doorbell ID
> range check in mana_gd_register_device() can rely on db_page_size
> being valid.
> 
> Fixes: 89fe91c65992 ("net: mana: hardening: Validate doorbell ID from GDMA_REGISTER_DEVICE response")
> Signed-off-by: Erni Sri Satya Vennela <[email-masked]>
> ---
> Changes in v2:
> * Remove "db_page_sz = max_t(u64, SZ_4K, gc->db_page_size)" in
>   mana_gd_register_device and validate db_page_sz at the source
>   mana_gf_init_pf_regs and mana_gd_init_vf_regs.
> * Update commit message.

Thanks for the update.

Reviewed-by: Simon Horman <[email-masked]>