Re: [PATCH] Staging: net: nic: Add error pointer check in otx2_flows.c

[Simon Horman <horms@kernel.org>]

On Sun, Sep 22, 2024 at 06:52:35PM +0000, Dipendra Khadka wrote:
> Smatch reported following:
> '''
> drivers/net/ethernet/marvell/octeontx2/nic/otx2_flows.c:123 otx2_alloc_mcam_entries() error: 'rsp' dereferencing possible ERR_PTR()
> drivers/net/ethernet/marvell/octeontx2/nic/otx2_flows.c:201 otx2_mcam_entry_init() error: 'rsp' dereferencing possible ERR_PTR()
> drivers/net/ethernet/marvell/octeontx2/nic/otx2_flows.c:236 otx2_mcam_entry_init() error: 'frsp' dereferencing possible ERR_PTR()
> '''
> 
> Adding error pointer check after calling otx2_mbox_get_rsp.
> 
> Signed-off-by: Dipendra Khadka <kdipendra88@gmail.com>

Hi Dipendra,

As noted by Andrew Lunn in relation to another patch [1],
this driver isn't in Staging so the subject is not correct.
And moreover, as Andrew suggested, please take a look at [2].

[1] https://lore.kernel.org/all/13fbb6c3-661f-477a-b33b-99303cd11622@lunn.ch/
[2] https://www.kernel.org/doc/html/latest/process/maintainer-netdev.html

> ---
>  .../ethernet/marvell/octeontx2/nic/otx2_flows.c   | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_flows.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_flows.c
> index 98c31a16c70b..4b61236c7c41 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_flows.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_flows.c
> @@ -120,6 +120,11 @@ int otx2_alloc_mcam_entries(struct otx2_nic *pfvf, u16 count)
>  		rsp = (struct npc_mcam_alloc_entry_rsp *)otx2_mbox_get_rsp
>  			(&pfvf->mbox.mbox, 0, &req->hdr);

nit: No blank line here please.
     Similarly in the other hunks of this patch.

>  
> +		if (IS_ERR(rsp)) {
> +			mutex_unlock(&bfvf->mbox.lock);

This doesn't compile as bfvf doesn't exit in this context.

> +			return PTR_ERR(rsp);

Looking at error handling elsewhere in the same loop, perhaps this
is appropriate instead of returning.

			goto exit;

> +		}
> +
>  		for (ent = 0; ent < rsp->count; ent++)
>  			flow_cfg->flow_ent[ent + allocated] = rsp->entry_list[ent];
>  

...