From fb745e9a037895321781d066aa24757ceabf9df9 Mon Sep 17 00:00:00 2001 From: David Ward Date: Thu, 11 Apr 2013 13:47:15 +0000 Subject: [PATCH] net/802/mrp: fix possible race condition when calling mrp_pdu_queue() (Adapted from a very similar change to net/802/garp.c by Cong Wang.) mrp_pdu_queue() should ways be called with the applicant spin lock. mrp_uninit_applicant() only holds the rtnl lock which is not enough; a race is possible because mrp_rcv() is called in BH context: mrp_rcv() |->mrp_pdu_parse_msg() |->mrp_pdu_parse_vecattr() |->mrp_pdu_parse_vecattr_event() |-> mrp_attr_event() |-> mrp_pdu_append_vecattr_event() |-> mrp_pdu_queue() Cc: Cong Wang Cc: Eric Dumazet Signed-off-by: David Ward Acked-by: Cong Wang Signed-off-by: David S. Miller --- net/802/mrp.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/802/mrp.c b/net/802/mrp.c index a4cc3229952a..e085bcc754f6 100644 --- a/net/802/mrp.c +++ b/net/802/mrp.c @@ -870,8 +870,12 @@ void mrp_uninit_applicant(struct net_device *dev, struct mrp_application *appl) * all pending messages before the applicant is gone. */ del_timer_sync(&app->join_timer); + + spin_lock(&app->lock); mrp_mad_event(app, MRP_EVENT_TX); mrp_pdu_queue(app); + spin_unlock(&app->lock); + mrp_queue_xmit(app); dev_mc_del(dev, appl->group_address); -- 2.20.1