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| author | Prasad J Pandit <pjp@fedoraproject.org> | 2018-06-05 23:38:35 +0530 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2018-06-08 09:08:30 +0300 |
| commit | 864036e251f54c99d31df124aad7f34f01f5344c (patch) | |
| tree | ca78196ce84b59fe837722729d93bc043d1192b0 /slirp/mbuf.c | |
| parent | 3835c310bd13662d5fb3f50f3dd62605dfd40cf9 (diff) | |
| download | focaccia-qemu-864036e251f54c99d31df124aad7f34f01f5344c.tar.gz focaccia-qemu-864036e251f54c99d31df124aad7f34f01f5344c.zip | |
slirp: correct size computation while concatenating mbuf
While reassembling incoming fragmented datagrams, 'm_cat' routine extends the 'mbuf' buffer, if it has insufficient room. It computes a wrong buffer size, which leads to overwriting adjacent heap buffer area. Correct this size computation in m_cat. Reported-by: ZDI Disclosures <zdi-disclosures@trendmicro.com> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Diffstat (limited to 'slirp/mbuf.c')
| -rw-r--r-- | slirp/mbuf.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/slirp/mbuf.c b/slirp/mbuf.c index 5ff24559fd..18cbf759a7 100644 --- a/slirp/mbuf.c +++ b/slirp/mbuf.c @@ -138,7 +138,7 @@ m_cat(struct mbuf *m, struct mbuf *n) * If there's no room, realloc */ if (M_FREEROOM(m) < n->m_len) - m_inc(m,m->m_size+MINCSIZE); + m_inc(m, m->m_len + n->m_len); memcpy(m->m_data+m->m_len, n->m_data, n->m_len); m->m_len += n->m_len; @@ -147,7 +147,7 @@ m_cat(struct mbuf *m, struct mbuf *n) } -/* make m size bytes large */ +/* make m 'size' bytes large from m_data */ void m_inc(struct mbuf *m, int size) { @@ -158,12 +158,12 @@ m_inc(struct mbuf *m, int size) if (m->m_flags & M_EXT) { datasize = m->m_data - m->m_ext; - m->m_ext = g_realloc(m->m_ext, size); + m->m_ext = g_realloc(m->m_ext, size + datasize); m->m_data = m->m_ext + datasize; } else { char *dat; datasize = m->m_data - m->m_dat; - dat = g_malloc(size); + dat = g_malloc(size + datasize); memcpy(dat, m->m_dat, m->m_size); m->m_ext = dat; @@ -171,8 +171,7 @@ m_inc(struct mbuf *m, int size) m->m_flags |= M_EXT; } - m->m_size = size; - + m->m_size = size + datasize; } |