Subject: Re: [PATCH net v1 2/3] octeon_ep: add checks to fix NULL pointer dereferences

From: Simon Horman <[email-masked]>
Date: Tue, 5 Nov 2024 12:25:16 +0000

On Fri, Nov 01, 2024 at 03:34:14AM -0700, Shinas Rasheed wrote:
> Add Checks to avoid NULL pointer references that might
> happen in rare and corner cases
> 
> Fixes: 6a610a46bad1 ("octeon_ep: add support for ndo ops")
> Fixes: 1f2c2d0cee02 ("octeon_ep: add hardware configuration APIs")
> Fixes: 0807dc76f3bf ("octeon_ep: support Octeon CN10K devices")

Hi Shinas,

As this has both three Fixes tags and three hunks, I suspect
it is fixing three separate but similar problems. And if so,
would be best split into three patches, one patch per problem.

Further, as an overall comment for the entire series, I think more
explanation of how these problems can arise is needed. Are they race
conditions, artifacts of tear-down or error handling, ... And what
execution paths lead to them? Stack traces, if available, would also be
useful to include.

> Signed-off-by: Shinas Rasheed <[email-masked]>
> ---
>  drivers/net/ethernet/marvell/octeon_ep/octep_cn9k_pf.c | 9 ++++++++-
>  drivers/net/ethernet/marvell/octeon_ep/octep_cnxk_pf.c | 9 ++++++++-
>  drivers/net/ethernet/marvell/octeon_ep/octep_main.c    | 3 +++
>  3 files changed, 19 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_cn9k_pf.c b/drivers/net/ethernet/marvell/octeon_ep/octep_cn9k_pf.c
> index b5805969404f..b87336b2e4b9 100644
> --- a/drivers/net/ethernet/marvell/octeon_ep/octep_cn9k_pf.c
> +++ b/drivers/net/ethernet/marvell/octeon_ep/octep_cn9k_pf.c
> @@ -617,7 +617,14 @@ static irqreturn_t octep_rsvd_intr_handler_cn93_pf(void *dev)
>  static irqreturn_t octep_ioq_intr_handler_cn93_pf(void *data)
>  {
>  	struct octep_ioq_vector *vector = (struct octep_ioq_vector *)data;
> -	struct octep_oq *oq = vector->oq;
> +	struct octep_oq *oq;
> +
> +	if (!vector)
> +		return IRQ_HANDLED;
> +	oq = vector->oq;
> +
> +	if (!oq || !(oq->napi))

nit: I don't think you need parentheses around op->napi. Likeiwse in patch 3/3.

> +		return IRQ_HANDLED;
>  
>  	napi_schedule_irqoff(oq->napi);
>  	return IRQ_HANDLED;

...

-- 
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