From owner-freebsd-stable@FreeBSD.ORG  Mon Dec 27 11:24:52 2004
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Date: Mon, 27 Dec 2004 12:24:49 WET
From: Johnny Eriksson <bygg@cafax.se>
To: freebsd-stable@freebsd.org
Message-ID: <CMM.0.91.0.1104146689.bygg@nic.cafax.se>
Subject: mbuf leak in bpf.c
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If one tries to write a datagram to a bpf device, and the datagram is
longer than the MTU on the physical interface, the write fails as it
should, but an mbuf is allocated and thrown away.  Proposed solution:

--- bpf.c.orig  Mon Dec 27 10:43:06 2004
+++ bpf.c       Mon Dec 27 10:44:16 2004
@@ -633,8 +633,10 @@
        if (error)
                return (error);
 
-       if (datlen > ifp->if_mtu)
+       if (datlen > ifp->if_mtu) {
+               m_freem(m);
                return (EMSGSIZE);
+       }
 
        if (d->bd_hdrcmplt)
                dst.sa_family = pseudo_AF_HDRCMPLT;

--Johnny