Thanks for your patch! This looks good to me.
From 1860546acd4d860f8e00e469a3e5e3617017a8c2 Mon Sep 17 00:00:00 2001
From: Yang Yingliang <[email protected]>
Date: Thu, 10 Nov 2022 23:08:22 +0800
Subject: [PATCH] mailbox: zynq-ipi: fix error handling while device_register()
fails
>
>If device_register() fails, it has two issues:
>1. The name allocated by dev_set_name() is leaked.
>2. The parent of device is not NULL, device_unregister() is called
> in zynqmp_ipi_free_mboxes(), it will lead a kernel crash because
> of removing not added device.
>
>Call put_device() to give up the reference, so the name is freed in
>kobject_cleanup(). Add device registered check in zynqmp_ipi_free_mboxes()
>to avoid null-ptr-deref.
>
>Fixes: 4981b82ba2ff ("mailbox: ZynqMP IPI mailbox controller")
>Signed-off-by: Yang Yingliang <[email protected]>
>---
> drivers/mailbox/zynqmp-ipi-mailbox.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/mailbox/zynqmp-ipi-mailbox.c b/drivers/mailbox/zynqmp-ipi-mailbox.c
>index 31a0fa914274..12e004ff1a14 100644
>--- a/drivers/mailbox/zynqmp-ipi-mailbox.c
>+++ b/drivers/mailbox/zynqmp-ipi-mailbox.c
>@@ -493,6 +493,7 @@ static int zynqmp_ipi_mbox_probe(struct zynqmp_ipi_mbox *ipi_mbox,
> ret = device_register(&ipi_mbox->dev);
> if (ret) {
> dev_err(dev, "Failed to register ipi mbox dev.\n");
>+ put_device(&ipi_mbox->dev);
> return ret;
> }
> mdev = &ipi_mbox->dev;
>@@ -619,7 +620,8 @@ static void zynqmp_ipi_free_mboxes(struct zynqmp_ipi_pdata *pdata)
> ipi_mbox = &pdata->ipi_mboxes[i];
> if (ipi_mbox->dev.parent) {
> mbox_controller_unregister(&ipi_mbox->mbox);
>- device_unregister(&ipi_mbox->dev);
>+ if (device_is_registered(&ipi_mbox->dev))
>+ device_unregister(&ipi_mbox->dev);
> }
> }
> }
>
--
2.25.1