| From 8f67e76e4148e37f3d8d2bcbdee7417fdedb7669 Mon Sep 17 00:00:00 2001 |
| From: Changqing Li <changqing.li@windriver.com> |
| Date: Thu, 27 Feb 2020 12:10:34 +0800 |
| Subject: [PATCH] slirp: use correct size while emulating commands |
| |
| While emulating services in tcp_emu(), it uses 'mbuf' size |
| 'm->m_size' to write commands via snprintf(3). Use M_FREEROOM(m) |
| size to avoid possible OOB access. |
| Signed-off-by: default avatarPrasad J Pandit <pjp@fedoraproject.org> |
| Signed-off-by: Samuel Thibault's avatarSamuel Thibault |
| <samuel.thibault@ens-lyon.org> |
| Message-Id: <20200109094228.79764-3-ppandit@redhat.com> |
| |
| CVE: CVE-2020-7039 |
| Upstream-Status: Backport |
| [https://gitlab.freedesktop.org/slirp/libslirp/commit/82ebe9c370a0e2970fb5695aa19aa5214a6a1c80] |
| |
| Signed-off-by: Changqing Li <changqing.li@windriver.com> |
| --- |
| slirp/src/tcp_subr.c | 9 ++++----- |
| 1 file changed, 4 insertions(+), 5 deletions(-) |
| |
| diff --git a/slirp/src/tcp_subr.c b/slirp/src/tcp_subr.c |
| index 4bea2d4..e8ed4ef 100644 |
| --- a/slirp/src/tcp_subr.c |
| +++ b/slirp/src/tcp_subr.c |
| @@ -696,7 +696,7 @@ int tcp_emu(struct socket *so, struct mbuf *m) |
| n4 = (laddr & 0xff); |
| |
| m->m_len = bptr - m->m_data; /* Adjust length */ |
| - m->m_len += snprintf(bptr, m->m_size - m->m_len, |
| + m->m_len += snprintf(bptr, M_FREEROOM(m), |
| "ORT %d,%d,%d,%d,%d,%d\r\n%s", n1, n2, n3, n4, |
| n5, n6, x == 7 ? buff : ""); |
| return 1; |
| @@ -731,8 +731,7 @@ int tcp_emu(struct socket *so, struct mbuf *m) |
| n4 = (laddr & 0xff); |
| |
| m->m_len = bptr - m->m_data; /* Adjust length */ |
| - m->m_len += |
| - snprintf(bptr, m->m_size - m->m_len, |
| + m->m_len += snprintf(bptr, M_FREEROOM(m), |
| "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s", |
| n1, n2, n3, n4, n5, n6, x == 7 ? buff : ""); |
| |
| @@ -758,8 +757,8 @@ int tcp_emu(struct socket *so, struct mbuf *m) |
| if (m->m_data[m->m_len - 1] == '\0' && lport != 0 && |
| (so = tcp_listen(slirp, INADDR_ANY, 0, so->so_laddr.s_addr, |
| htons(lport), SS_FACCEPTONCE)) != NULL) |
| - m->m_len = |
| - snprintf(m->m_data, m->m_size, "%d", ntohs(so->so_fport)) + 1; |
| + m->m_len = snprintf(m->m_data, M_ROOM(m), |
| + "%d", ntohs(so->so_fport)) + 1; |
| return 1; |
| |
| case EMU_IRC: |
| -- |
| 2.7.4 |
| |