From aa23c40365d8a12c2a30e1eced7a6dd160d87ebd Mon Sep 17 00:00:00 2001 From: Bruce Rogers Date: Sat, 5 Feb 2011 14:47:56 -0700 Subject: [PATCH] PATCH] slirp: fix buffer overrun Since the addition of the slirp member to struct mbuf, the value of SLIRP_MSIZE and the initialization of m_size have not been correct, resulting in overrunning the end of the malloc'd buffer in some cases. Signed-off-by: Bruce Rogers Signed-off-by: Anthony Liguori --- slirp/mbuf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/slirp/mbuf.c b/slirp/mbuf.c index 87508ba..eadc802 100644 --- a/slirp/mbuf.c +++ b/slirp/mbuf.c @@ -23,7 +23,7 @@ * Find a nice value for msize * XXX if_maxlinkhdr already in mtu */ -#define SLIRP_MSIZE (IF_MTU + IF_MAXLINKHDR + sizeof(struct m_hdr ) + 6) +#define SLIRP_MSIZE (IF_MTU + IF_MAXLINKHDR + offsetof(struct mbuf, m_dat) + 6) void m_init(Slirp *slirp) @@ -65,7 +65,7 @@ m_get(Slirp *slirp) m->m_flags = (flags | M_USEDLIST); /* Initialise it */ - m->m_size = SLIRP_MSIZE - sizeof(struct m_hdr); + m->m_size = SLIRP_MSIZE - offsetof(struct m_hdr, m_dat); m->m_data = m->m_dat; m->m_len = 0; m->m_nextpkt = NULL; -- 2.7.4