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authorJouni Hogander <jouni.hogander@unikie.com>2019-12-17 13:46:34 +0200
committerDavid S. Miller <davem@davemloft.net>2019-12-17 22:57:11 -0800
commitddd9b5e3e765d8ed5a35786a6cb00111713fe161 (patch)
treedfaa69217a2b2ce2bc86720999b5fa4ec1189da5 /net
parent39f14c00b13c47186739a4cbc7a16e04d7fdbb60 (diff)
downloadlinux-ddd9b5e3e765d8ed5a35786a6cb00111713fe161.tar.gz
net-sysfs: Call dev_hold always in rx_queue_add_kobject
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: b8eb718348b8 ("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>
Diffstat (limited to 'net')
-rw-r--r--net/core/net-sysfs.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 5c4624298996..4c826b8bf9b1 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -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)