| Upstream-Status: Backport |
| |
| https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg01012.html |
| |
| From dc21a9d2951f0a2a7e63633e2b5c68c54e4edc4b Mon Sep 17 00:00:00 2001 |
| From: Jeremy Puhlman <jpuhlman@mvista.com> |
| Date: Thu, 14 Jun 2018 01:28:49 +0000 |
| Subject: [PATCH] CVE-2018-11806 QEMU: slirp: heap buffer overflow |
| |
| Subject: [Qemu-devel] [PATCH 1/2] slirp: correct size computation while concatenating mbuf |
| Date: Tue, 5 Jun 2018 23:38:35 +0530 |
| From: Prasad J Pandit <address@hidden> |
| |
| 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 <address@hidden> |
| Signed-off-by: Prasad J Pandit <address@hidden> |
| --- |
| slirp/mbuf.c | 8 ++++---- |
| 1 file changed, 4 insertions(+), 4 deletions(-) |
| |
| Signed-off-by: Jeremy Puhlman <jpuhlman@mvista.com> |
| --- |
| slirp/mbuf.c | 8 ++++---- |
| 1 file changed, 4 insertions(+), 4 deletions(-) |
| |
| diff --git a/slirp/mbuf.c b/slirp/mbuf.c |
| index 5ff2455..7fb4501 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; |
| @@ -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; |
| @@ -171,7 +171,7 @@ m_inc(struct mbuf *m, int size) |
| m->m_flags |= M_EXT; |
| } |
| |
| - m->m_size = size; |
| + m->m_size = size + datasize; |
| |
| } |
| |
| -- |
| 2.13.3 |
| |