driver: svc-i3c-master: Kernel panic issue fixed

[PATCH] driver: svc-i3c-master: Kernel panic issue fixed

Posted by Manjunatha Venkatesh 9 months, 3 weeks ago

I3C Master driver svc-i3c-master

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@nxp.com>
---
 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

Re: [PATCH] driver: svc-i3c-master: Kernel panic issue fixed

Posted by Frank Li 9 months, 3 weeks ago

Subject should be "Fix read from unreadable memory at svc_i3c_master_ibi_work()"
Or like below pattern:
	Do ... to fix ...

On Mon, Feb 24, 2025 at 08:47:54AM +0530, Manjunatha Venkatesh wrote:
> I3C Master driver svc-i3c-master

Needn't this line.

>
> 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.

Can you provide more detail information why/how this happen? which varible
read cause this problem?

Need fix tags and cc stable.

Frank
>
> Signed-off-by: Manjunatha Venkatesh <manjunatha.venkatesh@nxp.com>
> ---
>  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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