[PATCH] i3c: master: Fix device_register() error path

Adrian Hunter <[email protected]> Thu, 2 Jul 2026 21:36:44 +0300
Newsgroups org.infradead.lists.linux-i3c,org.kernel.vger.linux-kernel
Organization Intel Finland Oy, Registered Address: c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo, Business Identity Code: 0357606 - 4, Domiciled in Helsinki
Message-ID <[email protected]>
When device_register() fails in i3c_master_register_new_i3c_devs(),
put_device() is called to drop the reference taken by
device_register().  That drops the last reference, so the device's
release callback i3c_device_release() runs and frees the i3c_device.

Two problems follow from that:

i3c_device_release() does WARN_ON(i3cdev->desc), so it warns because
desc->dev->desc still points back at the descriptor.  Clear it before
calling put_device().

After put_device() frees the i3c_device, desc->dev is left pointing at
freed memory, so clear desc->dev as well.  That prevents, for example,
i3c_master_unregister_i3c_devs() seeing desc->dev as non-NULL and
dereferencing it.

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-i3c/[email protected]/
Fixes: cab63f6488761 ("i3c: Fix potential refcount leak in i3c_master_register_new_i3c_devs")
Signed-off-by: Adrian Hunter <[email protected]>
---
 drivers/i3c/master.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 979457e635bd..7254b13fe4f0 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -1942,7 +1942,9 @@ i3c_master_register_new_i3c_devs(struct i3c_master_controller *master)
 		if (ret) {
 			dev_err(&master->dev,
 				"Failed to add I3C device (err = %d)\n", ret);
+			desc->dev->desc = NULL;
 			put_device(&desc->dev->dev);
+			desc->dev = NULL;
 		}
 	}
 }
-- 
2.53.0


-- 
linux-i3c mailing list
[email protected]
http://lists.infradead.org/mailman/listinfo/linux-i3c