Thread (5 messages) flat view 5 messages, 2 authors, 2d ago

Re: [PATCH v3 2/3] firmware/edd: use kobject_put() on edd_device_register() failure

From: Bjorn Helgaas <helgaas@kernel.org>
Date: 2026-08-14 22:06:53
Also in: driver-core, linux-arm-kernel, lkml

On Fri, Aug 14, 2026 at 09:00:56PM +0000, Tarun Sahu wrote:
As per koject_init_and_add() function kernel document, even if this
function returns error kobject_put must be used instead of kfree.
Thanks for adding this specific pointer.  I wouldn't repost just for
these nits, and wait at least a few days before reposting for any
reason.  But if you do repost:

s/koject_init_and_add/kobject_init_and_add/

Might also add "()" after function names consistently (kobject_put and
kfree above, edd_release below).  Also applies to the other patches.

The current subject lines basically restate the C code; you might
consider more of a focus on the problem.  I ran this through gemini
and I think it did a decent job:

  firmware: edd: Fix kobject reference leak on registration failure

  Per kobject_init_and_add() kernel-doc, calling kfree() directly on
  error bypasses reference counting and skips the kobject's release
  callback, leaking the reference.

  Use kobject_put() instead of kfree() on registration failure to fix
  this.
quoted hunk ↗ jump to hunk
When edd_device_register() fails after initializing the kobject with
kobject_init_and_add(), calling kfree(edev) directly bypasses the
kobject release callback (edd_release) and leaks the allocated kobject
resources.

Fix this by replacing direct kfree(edev) with kobject_put(&edev->kobj) on
registration failure.

Signed-off-by: Tarun Sahu <redacted>
Reviewed-by: Sourabh Jain <redacted>
---
 drivers/firmware/edd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/firmware/edd.c b/drivers/firmware/edd.c
index f980c5b56858..763e7b16d517 100644
--- a/drivers/firmware/edd.c
+++ b/drivers/firmware/edd.c
@@ -748,7 +748,7 @@ edd_init(void)
 
 		rc = edd_device_register(edev, i);
 		if (rc) {
-			kfree(edev);
+			kobject_put(&edev->kobj);
 			goto out;
 		}
 		edd_devices[i] = edev;
-- 
2.55.0.691.gc56d675ccc-goog
  
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