Re: [PATCH][next] net/mlx5: fix unintentional sign extension on shift of dest_attr->vport.vhca_id

[Simon Horman]

On Thu, Jan 16, 2025 at 06:17:00PM +0000, Colin Ian King wrote:
> Shifting dest_attr->vport.vhca_id << 16 results in a promotion from an
> unsigned 16 bit integer to a 32 bit signed integer, this is then sign
> extended to a 64 bit unsigned long on 64 bitarchitectures. If vhca_id is
> greater than 0x7fff then this leads to a sign extended result where all
> the upper 32 bits of idx are set to 1. Fix this by casting vhca_id
> to the same type as idx before performing the shift.
> 
> Fixes: 8e2e08a6d1e0 ("net/mlx5: fs, add support for dest vport HWS action")
> Signed-off-by: Colin Ian King <colin.i.king@xxxxxxxxx>

Reviewed-by: Simon Horman <horms@xxxxxxxxxx>