Re: [PATCH V1] accel/amdxdna: Guard management mailbox channel cleanup against NULL pointer

[Lizhi Hou]

Applied to drm-misc-next

On 4/16/26 15:46, Mario Limonciello wrote:
> On 4/16/26 15:11, Lizhi Hou wrote:
> > From: Max Zhen <max.zhen@xxxxxxx>
> >
> > The management mailbox channel cleanup helpers can be called from
> > error handling paths when mgmt_chann has already been destroyed.
> >
> > Add NULL checks to xdna_mailbox_free_channel() and
> > xdna_mailbox_stop_channel() so the cleanup path safely returns instead
> > of dereferencing a NULL mailbox channel pointer.
> >
> > Fixes: b87f920b9344 ("accel/amdxdna: Support hardware mailbox")
> > Signed-off-by: Max Zhen <max.zhen@xxxxxxx>
> > Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxx>
> > ---
> Reviewed-by: Mario Limonciello (AMD) <superm1@xxxxxxxxxx>
> >   drivers/accel/amdxdna/amdxdna_mailbox.c | 6 ++++++
> >   1 file changed, 6 insertions(+)
> >
> > diff --git a/drivers/accel/amdxdna/amdxdna_mailbox.c 
> > b/drivers/accel/amdxdna/amdxdna_mailbox.c
> > index 336e5e77f18a..37771bdb24a1 100644
> > --- a/drivers/accel/amdxdna/amdxdna_mailbox.c
> > +++ b/drivers/accel/amdxdna/amdxdna_mailbox.c
> > @@ -496,6 +496,9 @@ struct mailbox_channel 
> > *xdna_mailbox_alloc_channel(struct mailbox *mb)
> >     void xdna_mailbox_free_channel(struct mailbox_channel *mb_chann)
> >   {
> > +    if (!mb_chann)
> > +        return;
> > +
> >       destroy_workqueue(mb_chann->work_q);
> >       kfree(mb_chann);
> >   }
> > @@ -542,6 +545,9 @@ void xdna_mailbox_stop_channel(struct 
> > mailbox_channel *mb_chann)
> >       struct mailbox_msg *mb_msg;
> >       unsigned long msg_id;
> >   +    if (!mb_chann)
> > +        return;
> > +
> >       /* Disable an irq and wait. This might sleep. */
> >       free_irq(mb_chann->msix_irq, mb_chann);