Commit ec6f809f authored Nov 29, 2013 by Veaceslav Falico Committed by David S. Miller Nov 29, 2013

af_packet: block BH in prb_shutdown_retire_blk_timer()



Currently we're using plain spin_lock() in prb_shutdown_retire_blk_timer(),
however the timer might fire right in the middle and thus try to re-aquire
the same spinlock, leaving us in a endless loop.

To fix that, use the spin_lock_bh() to block it.

Fixes: f6fb8f10 ("af-packet: TPACKET_V3 flexible buffer implementation.")
CC: "David S. Miller" <davem@davemloft.net>
CC: Daniel Borkmann <dborkman@redhat.com>
CC: Willem de Bruijn <willemb@google.com>
CC: Phil Sutter <phil@nwl.cc>
CC: Eric Dumazet <edumazet@google.com>
Reported-by: Jan Stancek <jstancek@redhat.com>
Tested-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 006da7b0

net/packet/af_packet.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -439,9 +439,9 @@ static void prb_shutdown_retire_blk_timer(struct packet_sock *po,

		pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;

		spin_lock(&rb_queue->lock);
		spin_lock_bh(&rb_queue->lock);
		pkc->delete_blk_timer = 1;
		spin_unlock(&rb_queue->lock);
		spin_unlock_bh(&rb_queue->lock);

		prb_del_retire_blk_timer(pkc);
		}

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