Re: [PATCH net] Octeontx2-af: Fix negative array index read warning

[Joe Damato]

On Sun, Aug 10, 2025 at 11:33:27PM +0530, Chandra Mohan Sundar wrote:
> The cgx_get_cgxid function may return a negative value.
> Using this value directly as an array index triggers Coverity warnings.
> 
> Validate the returned value and handle the case gracefully.
> 
> Signed-off-by: Chandra Mohan Sundar <chandramohan.explore@xxxxxxxxx>
> ---
>  drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c b/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c
> index 8375f18c8e07..b14de93a2481 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c
> @@ -3005,6 +3005,8 @@ static int cgx_print_fwdata(struct seq_file *s, int lmac_id)
>  		return -EAGAIN;
>  
>  	cgx_id = cgx_get_cgxid(cgxd);
> +	if (cgx_id < 0)
> +		return -EINVAL;
>  
>  	if (rvu->hw->lmac_per_cgx == CGX_LMACS_USX)
>  		fwdata =  &rvu->fwdata->cgx_fw_data_usx[cgx_id][lmac_id];

A couple pieces of feedback for you:

1. Since this is a fixes it needs a Fixes tag and a commit SHA that it is fixing.
2. cgx_get_cgxid is called in 3 places, so your patch would probably need to
   be expanded to fix all uses?

Overall though, did you somehow trigger this issue?

It seems like all cases where cgx_get_cgxid is used it would be extremely
difficult (maybe impossible?) for cgxd to be NULL and for it to return a
negative value.