Commit fd2dab11 authored Dec 17, 2019 by Jouni Hogander Committed by Greg Kroah-Hartman Dec 31, 2019

net-sysfs: Call dev_hold always in rx_queue_add_kobject



[ Upstream commit ddd9b5e3e765d8ed5a35786a6cb00111713fe161 ]

Dev_hold has to be called always in rx_queue_add_kobject.
Otherwise usage count drops below 0 in case of failure in
kobject_init_and_add.

Fixes: b8eb7183 ("net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject")
Reported-by: syzbot <syzbot+30209ea299c09d8785c9@syzkaller.appspotmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Miller <davem@davemloft.net>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Jouni Hogander <jouni.hogander@unikie.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 3b1924a6

net/core/net-sysfs.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -919,14 +919,17 @@ static int rx_queue_add_kobject(struct net_device *dev, int index)
		struct kobject *kobj = &queue->kobj;
		int error = 0;

		/* Kobject_put later will trigger rx_queue_release call which
		* decreases dev refcount: Take that reference here
		*/
		dev_hold(queue->dev);

		kobj->kset = dev->queues_kset;
		error = kobject_init_and_add(kobj, &rx_queue_ktype, NULL,
		"rx-%u", index);
		if (error)
		goto err;

		dev_hold(queue->dev);

		if (dev->sysfs_rx_queue_group) {
		error = sysfs_create_group(kobj, dev->sysfs_rx_queue_group);
		if (error)