Date: Mon, 31 Jan 2011 12:17:07 -0500 From: John Baldwin <jhb@freebsd.org> To: net@freebsd.org Subject: Bogus KASSERT() in tcp_output()? Message-ID: <201101311217.07073.jhb@freebsd.org>
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Somewhat related fallout to the bug reported on security@ recently, I think
this KASSERT() in tcp_output() is bogus:
KASSERT(len + hdrlen + ipoptlen == m_length(m, NULL),
("%s: mbuf chain shorter than expected", __func__));
Specifically, just a few lines earlier in tcp_output() we set the packet
header length to just 'len + hdrlen':
/*
* Put TCP length in extended header, and then
* checksum extended header and data.
*/
m->m_pkthdr.len = hdrlen + len; /* in6_cksum() need this */
Also, the ipoptions are stored in a separate mbuf chain in the in pcb
(inp_options) that is passed as a separate argument to ip_output(). Given
that, I would think that m_length() should not reflect ipoptlen since it
should not include IP options in that chain?
--
John Baldwin
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