From 6be8e297f9bcea666ea85ac7a6cd9d52d6deaf92 Mon Sep 17 00:00:00 2001 From: Jeremy Sowden <jeremy@azazel.net> Date: Sun, 16 Jun 2019 16:54:37 +0100 Subject: [PATCH] lapb: fixed leak of control-blocks. 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> --- net/lapb/lapb_iface.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/lapb/lapb_iface.c b/net/lapb/lapb_iface.c index 03f0cd872dce..5d2d1f746b91 100644 --- a/net/lapb/lapb_iface.c +++ b/net/lapb/lapb_iface.c @@ -177,6 +177,7 @@ int lapb_unregister(struct net_device *dev) lapb = __lapb_devtostruct(dev); if (!lapb) goto out; + lapb_put(lapb); lapb_stop_t1timer(lapb); lapb_stop_t2timer(lapb);