Re: [PATCH v2] svc-i3c-master: Fix read from unreadable memory at svc_i3c_master_ibi_work()

[Frank Li]

On Thu, Mar 06, 2025 at 01:13:03PM +0530, Manjunatha Venkatesh wrote:
> As part of I3C driver probing sequence for particular device instance,
> While adding to queue it is trying to access ibi variable of dev which is
> not yet initialized causing "Unable to handle kernel read from unreadable
> memory" resulting in kernel panic.
>
> Signed-off-by: Manjunatha Venkatesh <manjunatha.venkatesh@xxxxxxx>
> ---

You sent it 3 times.

Do you try my suggestion at v1?
https://lore.kernel.org/linux-i3c/Z8m%2FzE9JvyiNq1HG@lizhi-Precision-Tower-5810/T/#t

Before close above discussion, please not sent new version.

Still missied fix tag and cc stable.

Frank

> Changes since v1:
>   - Patch tittle updated as per the review feedback
>
>  drivers/i3c/master/svc-i3c-master.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> index d6057d8c7dec..98c4d2e5cd8d 100644
> --- a/drivers/i3c/master/svc-i3c-master.c
> +++ b/drivers/i3c/master/svc-i3c-master.c
> @@ -534,8 +534,11 @@ static void svc_i3c_master_ibi_work(struct work_struct *work)
>  	switch (ibitype) {
>  	case SVC_I3C_MSTATUS_IBITYPE_IBI:
>  		if (dev) {
> -			i3c_master_queue_ibi(dev, master->ibi.tbq_slot);
> -			master->ibi.tbq_slot = NULL;
> +			data = i3c_dev_get_master_data(dev);
> +			if (master->ibi.slots[data->ibi]) {
> +				i3c_master_queue_ibi(dev, master->ibi.tbq_slot);
> +				master->ibi.tbq_slot = NULL;
> +			}
>  		}
>  		svc_i3c_master_emit_stop(master);
>  		break;
> --
> 2.46.1
>
>
> --
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