[PATCH 6.0 0877/1073] mailbox: zynq-ipi: fix error handling while device_register() fails

Greg Kroah-Hartman
2022-12-28T16:35:48Z

From: Yang Yingliang <yangyingliang@huawei.com>

[ Upstream commit a6792a0cdef0b1c2d77920246283a72537e60e94 ]

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 <yangyingliang@huawei.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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);
}
}
}
--
2.35.1