Re: [PATCH net V2 1/2] net/mlx5e: psp: Fix invalid access on PSP dev registration fail

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

Tariq Toukan wrote:
> From: Cosmin Ratiu <cratiu@nvidia.com>
> 
> priv->psp->psp is initialized with the PSP device as returned by
> psp_dev_create(). This could also return an error, in which case a
> future psp_dev_unregister() will result in unpleasantness.
> 
> Avoid that by using a local variable and only saving the PSP device when
> registration succeeds.
> Also apply some light refactoring of the functions managing the PSP
> device in order to make them more readable/safe.

This is generally discouraged as it obfuscates the fix.

That said, the fix on its own makes sense.

> In case psp_dev_create() fails, priv->psp and steering structs are left
> in place, but they will be inert. The unchecked access of priv->psp in
> mlx5e_psp_offload_handle_rx_skb() won't happen because without a PSP
> device, there can be no SAs added and therefore no packets will be
> successfully decrypted and be handed off to the SW handler.
> 
> Fixes: 89ee2d92f66c ("net/mlx5e: Support PSP offload functionality")
> Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
> Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
> Signed-off-by: Tariq Toukan <tariqt@nvidia.com>