lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Sun, 4 Jan 2015 18:02:27 +0200
From:	"Michael S. Tsirkin" <mst@...hat.com>
To:	linux-kernel@...r.kernel.org
Cc:	sasha.levin@...cle.com, virtualization@...ts.linux-foundation.org,
	stable@...r.kernel.org, Rusty Russell <rusty@...tcorp.com.au>
Subject: [PATCH 3/3] virtio_pci: document why we defer kfree

The reason we defer kfree until release function is because it's a
general rule for kobjects: kfree of the reference counter itself is only
legal in the release function.

Previous patch didn't make this clear, document this in code.

Cc: stable@...r.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@...hat.com>
---
 drivers/virtio/virtio_pci_legacy.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c
index 4beaee3..a5486e6 100644
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -216,6 +216,9 @@ static void virtio_pci_release_dev(struct device *_d)
 	struct virtio_device *vdev = dev_to_virtio(_d);
 	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 
+	/* As struct device is a kobject, it's not safe to
+	 * free the memory (including the reference counter itself)
+	 * until it's release callback. */
 	kfree(vp_dev);
 }
 
-- 
MST

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ