| From: Jouni Hogander <jouni.hogander@unikie.com> |
| Date: Tue, 17 Dec 2019 13:46:34 +0200 |
| Subject: net-sysfs: Call dev_hold always in rx_queue_add_kobject |
| |
| commit ddd9b5e3e765d8ed5a35786a6cb00111713fe161 upstream. |
| |
| 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> |
| [bwh: Backported to 3.16: adjust context] |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| net/core/net-sysfs.c | 7 +++++-- |
| 1 file changed, 5 insertions(+), 2 deletions(-) |
| |
| --- a/net/core/net-sysfs.c |
| +++ b/net/core/net-sysfs.c |
| @@ -782,14 +782,17 @@ static int rx_queue_add_kobject(struct n |
| 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 = net->queues_kset; |
| error = kobject_init_and_add(kobj, &rx_queue_ktype, NULL, |
| "rx-%u", index); |
| if (error) |
| goto err; |
| |
| - dev_hold(queue->dev); |
| - |
| if (net->sysfs_rx_queue_group) { |
| error = sysfs_create_group(kobj, net->sysfs_rx_queue_group); |
| if (error) |
