3.16.85-rc1 review patch. If anyone has any objections, please let me know.
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From: Jouni Hogander jouni.hogander@unikie.com
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)