From: Jeremy Sowden jeremy@azazel.net
[ Upstream commit 6be8e297f9bcea666ea85ac7a6cd9d52d6deaf92 ]
lapb_register calls lapb_create_cb, which initializes the control- block's ref-count to one, and __lapb_insert_cb, which increments it when adding the new block to the list of blocks.
lapb_unregister calls __lapb_remove_cb, which decrements the ref-count when removing control-block from the list of blocks, and calls lapb_put itself to decrement the ref-count before returning.
However, lapb_unregister also calls __lapb_devtostruct to look up the right control-block for the given net_device, and __lapb_devtostruct also bumps the ref-count, which means that when lapb_unregister returns the ref-count is still 1 and the control-block is leaked.
Call lapb_put after __lapb_devtostruct to fix leak.
Reported-by: syzbot+afb980676c836b4a0afa@syzkaller.appspotmail.com Signed-off-by: Jeremy Sowden jeremy@azazel.net Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/lapb/lapb_iface.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/lapb/lapb_iface.c +++ b/net/lapb/lapb_iface.c @@ -182,6 +182,7 @@ int lapb_unregister(struct net_device *d lapb = __lapb_devtostruct(dev); if (!lapb) goto out; + lapb_put(lapb);
lapb_stop_t1timer(lapb); lapb_stop_t2timer(lapb);