124 lines
5.4 KiB
Diff
124 lines
5.4 KiB
Diff
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From 2655fffed7a9e765bcb4701dd876e9dab975f289 Mon Sep 17 00:00:00 2001
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From: Samuel Thibault <samuel.thibault@ens-lyon.org>
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Date: Wed, 8 Jan 2020 00:58:48 +0100
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Subject: [PATCH] tcp_emu: Fix oob access
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The main loop only checks for one available byte, while we sometimes
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need two bytes.
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2.24.1
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From 82ebe9c370a0e2970fb5695aa19aa5214a6a1c80 Mon Sep 17 00:00:00 2001
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From: Prasad J Pandit <pjp@fedoraproject.org>
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Date: Thu, 9 Jan 2020 15:12:28 +0530
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Subject: [PATCH] slirp: use correct size while emulating commands
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While emulating services in tcp_emu(), it uses 'mbuf' size
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'm->m_size' to write commands via snprintf(3). Use M_FREEROOM(m)
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size to avoid possible OOB access.
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Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
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Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
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Message-Id: <20200109094228.79764-3-ppandit@redhat.com>
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2.24.1
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From ce131029d6d4a405cb7d3ac6716d03e58fb4a5d9 Mon Sep 17 00:00:00 2001
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From: Prasad J Pandit <pjp@fedoraproject.org>
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Date: Thu, 9 Jan 2020 15:12:27 +0530
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Subject: [PATCH] slirp: use correct size while emulating IRC commands
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While emulating IRC DCC commands, tcp_emu() uses 'mbuf' size
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'm->m_size' to write DCC commands via snprintf(3). This may
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lead to OOB write access, because 'bptr' points somewhere in
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the middle of 'mbuf' buffer, not at the start. Use M_FREEROOM(m)
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size to avoid OOB access.
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Reported-by: Vishnu Dev TJ <vishnudevtj@gmail.com>
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Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
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Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
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Message-Id: <20200109094228.79764-2-ppandit@redhat.com>
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---
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CHANGELOG.md | 1 +
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src/tcp_subr.c | 7 +++++++
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2 files changed, 8 insertions(+)
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diff -up slirp4netns-c4e1bc5a5e6987f3a352ca524f13320a2d483398/qemu/slirp/tcp_subr.c.CVE-2020-7039 slirp4netns-c4e1bc5a5e6987f3a352ca524f13320a2d483398/qemu/slirp/tcp_subr.c
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--- slirp4netns-c4e1bc5a5e6987f3a352ca524f13320a2d483398/qemu/slirp/tcp_subr.c.CVE-2020-7039 2020-01-16 11:13:39.558653385 +0100
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+++ slirp4netns-c4e1bc5a5e6987f3a352ca524f13320a2d483398/qemu/slirp/tcp_subr.c 2020-01-16 14:23:54.027184429 +0100
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@@ -704,7 +704,7 @@ tcp_emu(struct socket *so, struct mbuf *
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n4 = (laddr & 0xff);
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m->m_len = bptr - m->m_data; /* Adjust length */
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- m->m_len += snprintf(bptr, m->m_size - m->m_len,
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+ m->m_len += snprintf(bptr, M_FREEROOM(m),
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"ORT %d,%d,%d,%d,%d,%d\r\n%s",
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n1, n2, n3, n4, n5, n6, x==7?buff:"");
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return 1;
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@@ -737,7 +737,7 @@ tcp_emu(struct socket *so, struct mbuf *
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n4 = (laddr & 0xff);
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m->m_len = bptr - m->m_data; /* Adjust length */
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- m->m_len += snprintf(bptr, m->m_size - m->m_len,
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+ m->m_len += snprintf(bptr, M_FREEROOM(m),
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"27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s",
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n1, n2, n3, n4, n5, n6, x==7?buff:"");
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@@ -763,7 +763,7 @@ tcp_emu(struct socket *so, struct mbuf *
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if (m->m_data[m->m_len-1] == '\0' && lport != 0 &&
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(so = tcp_listen(slirp, INADDR_ANY, 0, so->so_laddr.s_addr,
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htons(lport), SS_FACCEPTONCE)) != NULL)
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- m->m_len = snprintf(m->m_data, m->m_size, "%d",
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+ m->m_len = snprintf(m->m_data, M_ROOM(m), "%d",
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ntohs(so->so_fport)) + 1;
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return 1;
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@@ -783,7 +783,7 @@ tcp_emu(struct socket *so, struct mbuf *
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return 1;
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}
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m->m_len = bptr - m->m_data; /* Adjust length */
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- m->m_len += snprintf(bptr, m->m_size,
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+ m->m_len += snprintf(bptr, M_FREEROOM(m),
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"DCC CHAT chat %lu %u%c\n",
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(unsigned long)ntohl(so->so_faddr.s_addr),
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ntohs(so->so_fport), 1);
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@@ -794,7 +794,7 @@ tcp_emu(struct socket *so, struct mbuf *
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return 1;
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}
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m->m_len = bptr - m->m_data; /* Adjust length */
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- m->m_len += snprintf(bptr, m->m_size,
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+ m->m_len += snprintf(bptr, M_FREEROOM(m),
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"DCC SEND %s %lu %u %u%c\n", buff,
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(unsigned long)ntohl(so->so_faddr.s_addr),
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ntohs(so->so_fport), n1, 1);
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@@ -805,7 +805,7 @@ tcp_emu(struct socket *so, struct mbuf *
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return 1;
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}
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m->m_len = bptr - m->m_data; /* Adjust length */
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- m->m_len += snprintf(bptr, m->m_size,
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+ m->m_len += snprintf(bptr, M_FREEROOM(m),
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"DCC MOVE %s %lu %u %u%c\n", buff,
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(unsigned long)ntohl(so->so_faddr.s_addr),
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ntohs(so->so_fport), n1, 1);
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@@ -892,6 +892,9 @@ tcp_emu(struct socket *so, struct mbuf *
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break;
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case 5:
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+ if (bptr == m->m_data + m->m_len - 1)
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+ return 1; /* We need two bytes */
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+
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/*
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* The difference between versions 1.0 and
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* 2.0 is here. For future versions of
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@@ -907,6 +910,9 @@ tcp_emu(struct socket *so, struct mbuf *
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/* This is the field containing the port
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* number that RA-player is listening to.
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*/
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+ if (bptr == m->m_data + m->m_len - 1)
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+ return 1; /* We need two bytes */
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+
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lport = (((u_char*)bptr)[0] << 8)
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+ ((u_char *)bptr)[1];
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if (lport < 6970)
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