|
 |
95229b |
From 901de585a893830992a137f6e191434b2f533428 Mon Sep 17 00:00:00 2001
|
|
|
95229b |
From: jmaloy <jmaloy@redhat.com>
|
|
|
95229b |
Date: Thu, 13 Feb 2020 21:08:18 +0100
|
|
|
95229b |
Subject: [PATCH 2/2] tcp_emu: fix unsafe snprintf() usages
|
|
|
95229b |
MIME-Version: 1.0
|
|
|
95229b |
Content-Type: text/plain; charset=UTF-8
|
|
|
95229b |
Content-Transfer-Encoding: 8bit
|
|
|
95229b |
|
|
|
95229b |
Message-id: <20200213210818.9090-3-jmaloy@redhat.com>
|
|
|
95229b |
Patchwork-id: 93832
|
|
|
95229b |
O-Subject: [RHEL-7.8 qemu-kvm PATCH 2/2] tcp_emu: fix unsafe snprintf() usages
|
|
|
95229b |
Bugzilla: 1798970
|
|
|
95229b |
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
|
|
|
95229b |
RH-Acked-by: Eduardo Habkost <ehabkost@redhat.com>
|
|
|
95229b |
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
|
|
|
95229b |
|
|
|
95229b |
From: Marc-André Lureau <marcandre.lureau@redhat.com>
|
|
|
95229b |
|
|
|
95229b |
Various calls to snprintf() assume that snprintf() returns "only" the
|
|
|
95229b |
number of bytes written (excluding terminating NUL).
|
|
|
95229b |
|
|
|
95229b |
https://pubs.opengroup.org/onlinepubs/9699919799/functions/snprintf.html#tag_16_159_04
|
|
|
95229b |
|
|
|
95229b |
"Upon successful completion, the snprintf() function shall return the
|
|
|
95229b |
number of bytes that would be written to s had n been sufficiently
|
|
|
95229b |
large excluding the terminating null byte."
|
|
|
95229b |
|
|
|
95229b |
Before patch ce131029, if there isn't enough room in "m_data" for the
|
|
|
95229b |
"DCC ..." message, we overflow "m_data".
|
|
|
95229b |
|
|
|
95229b |
After the patch, if there isn't enough room for the same, we don't
|
|
|
95229b |
overflow "m_data", but we set "m_len" out-of-bounds. The next time an
|
|
|
95229b |
access is bounded by "m_len", we'll have a buffer overflow then.
|
|
|
95229b |
|
|
|
95229b |
Use slirp_fmt*() to fix potential OOB memory access.
|
|
|
95229b |
|
|
|
95229b |
Reported-by: Laszlo Ersek <lersek@redhat.com>
|
|
|
95229b |
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
|
|
|
95229b |
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
|
|
|
95229b |
Message-Id: <20200127092414.169796-7-marcandre.lureau@redhat.com>
|
|
|
95229b |
(cherry picked from commit 68ccb8021a838066f0951d4b2817eb6b6f10a843)
|
|
|
95229b |
|
|
|
95229b |
Manually re-adapted since the cherry-pick didn't apply cleanly.
|
|
|
95229b |
|
|
|
95229b |
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
|
|
|
95229b |
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
|
|
|
95229b |
---
|
|
|
95229b |
slirp/tcp_subr.c | 44 +++++++++++++++++++++-----------------------
|
|
|
95229b |
1 file changed, 21 insertions(+), 23 deletions(-)
|
|
|
95229b |
|
|
|
95229b |
diff --git a/slirp/tcp_subr.c b/slirp/tcp_subr.c
|
|
|
95229b |
index e83575e..8dae0cc 100644
|
|
|
95229b |
--- a/slirp/tcp_subr.c
|
|
|
95229b |
+++ b/slirp/tcp_subr.c
|
|
|
95229b |
@@ -610,8 +610,7 @@ tcp_emu(struct socket *so, struct mbuf *m)
|
|
|
95229b |
NTOHS(n1);
|
|
|
95229b |
NTOHS(n2);
|
|
|
95229b |
m_inc(m, snprintf(NULL, 0, "%d,%d\r\n", n1, n2) + 1);
|
|
|
95229b |
- m->m_len = snprintf(m->m_data, M_ROOM(m), "%d,%d\r\n", n1, n2);
|
|
|
95229b |
- assert(m->m_len < M_ROOM(m));
|
|
|
95229b |
+ m->m_len = slirp_fmt(m->m_data, M_ROOM(m), "%d,%d\r\n", n1, n2);
|
|
|
95229b |
} else {
|
|
|
95229b |
*eol = '\r';
|
|
|
95229b |
}
|
|
|
95229b |
@@ -651,9 +650,9 @@ tcp_emu(struct socket *so, struct mbuf *m)
|
|
|
95229b |
n4 = (laddr & 0xff);
|
|
|
95229b |
|
|
|
95229b |
m->m_len = bptr - m->m_data; /* Adjust length */
|
|
|
95229b |
- m->m_len += snprintf(bptr, M_FREEROOM(m),
|
|
|
95229b |
- "ORT %d,%d,%d,%d,%d,%d\r\n%s",
|
|
|
95229b |
- n1, n2, n3, n4, n5, n6, x==7?buff:"");
|
|
|
95229b |
+ m->m_len += slirp_fmt(bptr, M_FREEROOM(m),
|
|
|
95229b |
+ "ORT %d,%d,%d,%d,%d,%d\r\n%s",
|
|
|
95229b |
+ n1, n2, n3, n4, n5, n6, x == 7 ? buff : "");
|
|
|
95229b |
return 1;
|
|
|
95229b |
} else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) {
|
|
|
95229b |
/*
|
|
|
95229b |
@@ -684,10 +683,9 @@ tcp_emu(struct socket *so, struct mbuf *m)
|
|
|
95229b |
n4 = (laddr & 0xff);
|
|
|
95229b |
|
|
|
95229b |
m->m_len = bptr - m->m_data; /* Adjust length */
|
|
|
95229b |
- m->m_len += snprintf(bptr, M_FREEROOM(m),
|
|
|
95229b |
- "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s",
|
|
|
95229b |
- n1, n2, n3, n4, n5, n6, x==7?buff:"");
|
|
|
95229b |
-
|
|
|
95229b |
+ m->m_len += slirp_fmt(bptr, M_FREEROOM(m),
|
|
|
95229b |
+ "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s",
|
|
|
95229b |
+ n1, n2, n3, n4, n5, n6, x == 7 ? buff : "");
|
|
|
95229b |
return 1;
|
|
|
95229b |
}
|
|
|
95229b |
|
|
|
95229b |
@@ -710,8 +708,8 @@ tcp_emu(struct socket *so, struct mbuf *m)
|
|
|
95229b |
if (m->m_data[m->m_len-1] == '\0' && lport != 0 &&
|
|
|
95229b |
(so = tcp_listen(slirp, INADDR_ANY, 0, so->so_laddr.s_addr,
|
|
|
95229b |
htons(lport), SS_FACCEPTONCE)) != NULL)
|
|
|
95229b |
- m->m_len = snprintf(m->m_data, M_ROOM(m),
|
|
|
95229b |
- "%d", ntohs(so->so_fport)) + 1;
|
|
|
95229b |
+ m->m_len = slirp_fmt0(m->m_data, M_ROOM(m),
|
|
|
95229b |
+ "%d", ntohs(so->so_fport));
|
|
|
95229b |
return 1;
|
|
|
95229b |
|
|
|
95229b |
case EMU_IRC:
|
|
|
95229b |
@@ -731,10 +729,10 @@ tcp_emu(struct socket *so, struct mbuf *m)
|
|
|
95229b |
return 1;
|
|
|
95229b |
}
|
|
|
95229b |
m->m_len = bptr - m->m_data; /* Adjust length */
|
|
|
95229b |
- m->m_len += snprintf(bptr, M_FREEROOM(m),
|
|
|
95229b |
- "DCC CHAT chat %lu %u%c\n",
|
|
|
95229b |
- (unsigned long)ntohl(so->so_faddr.s_addr),
|
|
|
95229b |
- ntohs(so->so_fport), 1);
|
|
|
95229b |
+ m->m_len += slirp_fmt(bptr, M_FREEROOM(m),
|
|
|
95229b |
+ "DCC CHAT chat %lu %u%c\n",
|
|
|
95229b |
+ (unsigned long)ntohl(so->so_faddr.s_addr),
|
|
|
95229b |
+ ntohs(so->so_fport), 1);
|
|
|
95229b |
} else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
|
|
|
95229b |
if ((so = tcp_listen(slirp, INADDR_ANY, 0,
|
|
|
95229b |
htonl(laddr), htons(lport),
|
|
|
95229b |
@@ -742,10 +740,10 @@ tcp_emu(struct socket *so, struct mbuf *m)
|
|
|
95229b |
return 1;
|
|
|
95229b |
}
|
|
|
95229b |
m->m_len = bptr - m->m_data; /* Adjust length */
|
|
|
95229b |
- m->m_len += snprintf(bptr, M_FREEROOM(m),
|
|
|
95229b |
- "DCC SEND %s %lu %u %u%c\n", buff,
|
|
|
95229b |
- (unsigned long)ntohl(so->so_faddr.s_addr),
|
|
|
95229b |
- ntohs(so->so_fport), n1, 1);
|
|
|
95229b |
+ m->m_len += slirp_fmt(bptr, M_FREEROOM(m),
|
|
|
95229b |
+ "DCC SEND %s %lu %u %u%c\n", buff,
|
|
|
95229b |
+ (unsigned long)ntohl(so->so_faddr.s_addr),
|
|
|
95229b |
+ ntohs(so->so_fport), n1, 1);
|
|
|
95229b |
} else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
|
|
|
95229b |
if ((so = tcp_listen(slirp, INADDR_ANY, 0,
|
|
|
95229b |
htonl(laddr), htons(lport),
|
|
|
95229b |
@@ -753,10 +751,10 @@ tcp_emu(struct socket *so, struct mbuf *m)
|
|
|
95229b |
return 1;
|
|
|
95229b |
}
|
|
|
95229b |
m->m_len = bptr - m->m_data; /* Adjust length */
|
|
|
95229b |
- m->m_len += snprintf(bptr, M_FREEROOM(m),
|
|
|
95229b |
- "DCC MOVE %s %lu %u %u%c\n", buff,
|
|
|
95229b |
- (unsigned long)ntohl(so->so_faddr.s_addr),
|
|
|
95229b |
- ntohs(so->so_fport), n1, 1);
|
|
|
95229b |
+ m->m_len += slirp_fmt(bptr, M_FREEROOM(m),
|
|
|
95229b |
+ "DCC MOVE %s %lu %u %u%c\n", buff,
|
|
|
95229b |
+ (unsigned long)ntohl(so->so_faddr.s_addr),
|
|
|
95229b |
+ ntohs(so->so_fport), n1, 1);
|
|
|
95229b |
}
|
|
|
95229b |
return 1;
|
|
|
95229b |
|
|
|
95229b |
--
|
|
|
95229b |
1.8.3.1
|
|
|
95229b |
|