From: David Ward <david.ward@ll.mit.edu>
Date: Thu, 11 Apr 2013 13:47:15 +0000 (+0000)
Subject: net/802/mrp: fix possible race condition when calling mrp_pdu_queue()
X-Git-Tag: v3.9-rc8~20^2~10
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fb745e9a037895321781d066aa24757ceabf9df9;p=pandora-kernel.git

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 <amwang@redhat.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Acked-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

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