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CentOS Sources 2020-07-28 03:29:07 -04:00 committed by Stepan Oksanichenko
parent 4fd6ba9570
commit 25acb1cef1
3 changed files with 398 additions and 1 deletions
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132
SOURCES/slirp4netns-CVE-2020-7039.patch Normal file
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@ -0,0 +1,132 @@
From 2655fffed7a9e765bcb4701dd876e9dab975f289 Mon Sep 17 00:00:00 2001
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Wed, 8 Jan 2020 00:58:48 +0100
Subject: [PATCH] tcp_emu: Fix oob access
The main loop only checks for one available byte, while we sometimes
need two bytes.
2.24.1
From 82ebe9c370a0e2970fb5695aa19aa5214a6a1c80 Mon Sep 17 00:00:00 2001
From: Prasad J Pandit <pjp@fedoraproject.org>
Date: Thu, 9 Jan 2020 15:12:28 +0530
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: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Message-Id: <20200109094228.79764-3-ppandit@redhat.com>
2.24.1
From ce131029d6d4a405cb7d3ac6716d03e58fb4a5d9 Mon Sep 17 00:00:00 2001
From: Prasad J Pandit <pjp@fedoraproject.org>
Date: Thu, 9 Jan 2020 15:12:27 +0530
Subject: [PATCH] slirp: use correct size while emulating IRC commands
While emulating IRC DCC commands, tcp_emu() uses 'mbuf' size
'm->m_size' to write DCC commands via snprintf(3). This may
lead to OOB write access, because 'bptr' points somewhere in
the middle of 'mbuf' buffer, not at the start. Use M_FREEROOM(m)
size to avoid OOB access.
Reported-by: Vishnu Dev TJ <vishnudevtj@gmail.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Message-Id: <20200109094228.79764-2-ppandit@redhat.com>
---
CHANGELOG.md | 1 +
src/tcp_subr.c | 7 +++++++
2 files changed, 8 insertions(+)
diff -up ./slirp4netns-21fdece2737dc24ffa3f01a341b8a6854f8b13b4/vendor/libslirp/src/tcp_subr.c.CVE-2020-7039 ./slirp4netns-21fdece2737dc24ffa3f01a341b8a6854f8b13b4/vendor/libslirp/src/tcp_subr.c
--- slirp4netns-21fdece2737dc24ffa3f01a341b8a6854f8b13b4/vendor/libslirp/src/tcp_subr.c.CVE-2020-7039 2020-01-16 11:13:43.472696979 +0100
+++ slirp4netns-21fdece2737dc24ffa3f01a341b8a6854f8b13b4/vendor/libslirp/src/tcp_subr.c 2020-01-16 11:13:43.474697002 +0100
@@ -692,7 +692,7 @@ int tcp_emu(struct socket *so, struct mb
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;
@@ -727,8 +727,7 @@ int tcp_emu(struct socket *so, struct mb
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 : "");
@@ -754,8 +753,8 @@ int tcp_emu(struct socket *so, struct mb
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:
@@ -774,7 +773,8 @@ int tcp_emu(struct socket *so, struct mb
return 1;
}
m->m_len = bptr - m->m_data; /* Adjust length */
- m->m_len += snprintf(bptr, m->m_size, "DCC CHAT chat %lu %u%c\n",
+ m->m_len += snprintf(bptr, M_FREEROOM(m),
+ "DCC CHAT chat %lu %u%c\n",
(unsigned long)ntohl(so->so_faddr.s_addr),
ntohs(so->so_fport), 1);
} else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport,
@@ -784,8 +784,8 @@ int tcp_emu(struct socket *so, struct mb
return 1;
}
m->m_len = bptr - m->m_data; /* Adjust length */
- m->m_len +=
- snprintf(bptr, m->m_size, "DCC SEND %s %lu %u %u%c\n", buff,
+ m->m_len += snprintf(bptr, M_FREEROOM(m),
+ "DCC SEND %s %lu %u %u%c\n", buff,
(unsigned long)ntohl(so->so_faddr.s_addr),
ntohs(so->so_fport), n1, 1);
} else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport,
@@ -795,8 +795,8 @@ int tcp_emu(struct socket *so, struct mb
return 1;
}
m->m_len = bptr - m->m_data; /* Adjust length */
- m->m_len +=
- snprintf(bptr, m->m_size, "DCC MOVE %s %lu %u %u%c\n", buff,
+ m->m_len += snprintf(bptr, M_FREEROOM(m),
+ "DCC MOVE %s %lu %u %u%c\n", buff,
(unsigned long)ntohl(so->so_faddr.s_addr),
ntohs(so->so_fport), n1, 1);
}
@@ -882,6 +882,9 @@ int tcp_emu(struct socket *so, struct mb
break;
case 5:
+ if (bptr == m->m_data + m->m_len - 1)
+ return 1; /* We need two bytes */
+
/*
* The difference between versions 1.0 and
* 2.0 is here. For future versions of
@@ -897,6 +900,10 @@ int tcp_emu(struct socket *so, struct mb
/* This is the field containing the port
* number that RA-player is listening to.
*/
+
+ if (bptr == m->m_data + m->m_len - 1)
+ return 1; /* We need two bytes */
+
lport = (((uint8_t *)bptr)[0] << 8) + ((uint8_t *)bptr)[1];
if (lport < 6970)
lport += 256; /* don't know why */

255
SOURCES/slirp4netns-CVE-2020-8608.patch Normal file
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@ -0,0 +1,255 @@
From 68ccb8021a838066f0951d4b2817eb6b6f10a843 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>
Date: Mon, 27 Jan 2020 10:24:14 +0100
Subject: [PATCH] tcp_emu: fix unsafe snprintf() usages
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Various calls to snprintf() assume that snprintf() returns "only" the
number of bytes written (excluding terminating NUL).
https://pubs.opengroup.org/onlinepubs/9699919799/functions/snprintf.html#tag_16_159_04
"Upon successful completion, the snprintf() function shall return the
number of bytes that would be written to s had n been sufficiently
large excluding the terminating null byte."
Before patch ce131029, if there isn't enough room in "m_data" for the
"DCC ..." message, we overflow "m_data".
After the patch, if there isn't enough room for the same, we don't
overflow "m_data", but we set "m_len" out-of-bounds. The next time an
access is bounded by "m_len", we'll have a buffer overflow then.
Use slirp_fmt*() to fix potential OOB memory access.
Reported-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Message-Id: <20200127092414.169796-7-marcandre.lureau@redhat.com>
---
src/tcp_subr.c | 44 +++++++++++++++++++++-----------------------
1 file changed, 21 insertions(+), 23 deletions(-)
diff -up ./slirp4netns-2244b9b6461afeccad1678fac3d6e478c28b4ad6/vendor/libslirp/src/tcp_subr.c.CVE-2020-8608 ./slirp4netns-2244b9b6461afeccad1678fac3d6e478c28b4ad6/vendor/libslirp/src/tcp_subr.c
--- slirp4netns-2244b9b6461afeccad1678fac3d6e478c28b4ad6/vendor/libslirp/src/tcp_subr.c.CVE-2020-8608 2020-02-06 13:31:33.592822770 +0100
+++ slirp4netns-2244b9b6461afeccad1678fac3d6e478c28b4ad6/vendor/libslirp/src/tcp_subr.c 2020-02-06 13:31:33.594822795 +0100
@@ -640,8 +640,7 @@ int tcp_emu(struct socket *so, struct mb
NTOHS(n1);
NTOHS(n2);
m_inc(m, snprintf(NULL, 0, "%d,%d\r\n", n1, n2) + 1);
- m->m_len = snprintf(m->m_data, M_ROOM(m), "%d,%d\r\n", n1, n2);
- assert(m->m_len < M_ROOM(m));
+ m->m_len = slirp_fmt(m->m_data, M_ROOM(m), "%d,%d\r\n", n1, n2);
} else {
*eol = '\r';
}
@@ -681,9 +680,9 @@ int tcp_emu(struct socket *so, struct mb
n4 = (laddr & 0xff);
m->m_len = bptr - m->m_data; /* Adjust length */
- 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 : "");
+ m->m_len += slirp_fmt(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;
} else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) {
/*
@@ -716,10 +715,9 @@ int tcp_emu(struct socket *so, struct mb
n4 = (laddr & 0xff);
m->m_len = bptr - m->m_data; /* Adjust length */
- 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 : "");
-
+ m->m_len += slirp_fmt(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 : "");
return 1;
}
@@ -742,8 +740,8 @@ int tcp_emu(struct socket *so, struct mb
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_ROOM(m),
- "%d", ntohs(so->so_fport)) + 1;
+ m->m_len = slirp_fmt0(m->m_data, M_ROOM(m),
+ "%d", ntohs(so->so_fport));
return 1;
case EMU_IRC:
@@ -762,10 +760,10 @@ int tcp_emu(struct socket *so, struct mb
return 1;
}
m->m_len = bptr - m->m_data; /* Adjust length */
- m->m_len += snprintf(bptr, M_FREEROOM(m),
- "DCC CHAT chat %lu %u%c\n",
- (unsigned long)ntohl(so->so_faddr.s_addr),
- ntohs(so->so_fport), 1);
+ m->m_len += slirp_fmt(bptr, M_FREEROOM(m),
+ "DCC CHAT chat %lu %u%c\n",
+ (unsigned long)ntohl(so->so_faddr.s_addr),
+ ntohs(so->so_fport), 1);
} else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport,
&n1) == 4) {
if ((so = tcp_listen(slirp, INADDR_ANY, 0, htonl(laddr),
@@ -773,10 +771,10 @@ int tcp_emu(struct socket *so, struct mb
return 1;
}
m->m_len = bptr - m->m_data; /* Adjust length */
- m->m_len += snprintf(bptr, M_FREEROOM(m),
- "DCC SEND %s %lu %u %u%c\n", buff,
- (unsigned long)ntohl(so->so_faddr.s_addr),
- ntohs(so->so_fport), n1, 1);
+ m->m_len += slirp_fmt(bptr, M_FREEROOM(m),
+ "DCC SEND %s %lu %u %u%c\n", buff,
+ (unsigned long)ntohl(so->so_faddr.s_addr),
+ ntohs(so->so_fport), n1, 1);
} else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport,
&n1) == 4) {
if ((so = tcp_listen(slirp, INADDR_ANY, 0, htonl(laddr),
@@ -784,10 +782,10 @@ int tcp_emu(struct socket *so, struct mb
return 1;
}
m->m_len = bptr - m->m_data; /* Adjust length */
- m->m_len += snprintf(bptr, M_FREEROOM(m),
- "DCC MOVE %s %lu %u %u%c\n", buff,
- (unsigned long)ntohl(so->so_faddr.s_addr),
- ntohs(so->so_fport), n1, 1);
+ m->m_len += slirp_fmt(bptr, M_FREEROOM(m),
+ "DCC MOVE %s %lu %u %u%c\n", buff,
+ (unsigned long)ntohl(so->so_faddr.s_addr),
+ ntohs(so->so_fport), n1, 1);
}
return 1;
From 30648c03b27fb8d9611b723184216cd3174b6775 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>
Date: Mon, 27 Jan 2020 10:24:09 +0100
Subject: [PATCH] util: add slirp_fmt() helpers
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Various calls to snprintf() in libslirp assume that snprintf() returns
"only" the number of bytes written (excluding terminating NUL).
https://pubs.opengroup.org/onlinepubs/9699919799/functions/snprintf.html#tag_16_159_04
"Upon successful completion, the snprintf() function shall return the
number of bytes that would be written to s had n been sufficiently
large excluding the terminating null byte."
Introduce slirp_fmt() that handles several pathological cases the
way libslirp usually expect:
- treat error as fatal (instead of silently returning -1)
- fmt0() will always \0 end
- return the number of bytes actually written (instead of what would
have been written, which would usually result in OOB later), including
the ending \0 for fmt0()
- warn if truncation happened (instead of ignoring)
Other less common cases can still be handled with strcpy/snprintf() etc.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Message-Id: <20200127092414.169796-2-marcandre.lureau@redhat.com>
---
src/util.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
src/util.h | 3 +++
2 files changed, 65 insertions(+)
diff --git a/src/util.c b/src/util.c
index e596087..e3b6257 100644
--- a/vendor/libslirp/src/util.c
+++ b/vendor/libslirp/src/util.c
@@ -364,3 +364,65 @@ void slirp_pstrcpy(char *buf, int buf_size, const char *str)
}
*q = '\0';
}
+
+static int slirp_vsnprintf(char *str, size_t size,
+ const char *format, va_list args)
+{
+ int rv = vsnprintf(str, size, format, args);
+
+ if (rv < 0) {
+ g_error("vsnprintf() failed: %s", g_strerror(errno));
+ }
+
+ return rv;
+}
+
+/*
+ * A snprintf()-like function that:
+ * - returns the number of bytes written (excluding optional \0-ending)
+ * - dies on error
+ * - warn on truncation
+ */
+int slirp_fmt(char *str, size_t size, const char *format, ...)
+{
+ va_list args;
+ int rv;
+
+ va_start(args, format);
+ rv = slirp_vsnprintf(str, size, format, args);
+ va_end(args);
+
+ if (rv > size) {
+ g_critical("vsnprintf() truncation");
+ }
+
+ return MIN(rv, size);
+}
+
+/*
+ * A snprintf()-like function that:
+ * - always \0-end (unless size == 0)
+ * - returns the number of bytes actually written, including \0 ending
+ * - dies on error
+ * - warn on truncation
+ */
+int slirp_fmt0(char *str, size_t size, const char *format, ...)
+{
+ va_list args;
+ int rv;
+
+ va_start(args, format);
+ rv = slirp_vsnprintf(str, size, format, args);
+ va_end(args);
+
+ if (rv >= size) {
+ g_critical("vsnprintf() truncation");
+ if (size > 0)
+ str[size - 1] = '\0';
+ rv = size;
+ } else {
+ rv += 1; /* include \0 */
+ }
+
+ return rv;
+}
diff --git a/src/util.h b/src/util.h
index e9c3073..5530c46 100644
--- a/vendor/libslirp/src/util.h
+++ b/vendor/libslirp/src/util.h
@@ -181,4 +181,7 @@ static inline int slirp_socket_set_fast_reuse(int fd)
void slirp_pstrcpy(char *buf, int buf_size, const char *str);
+int slirp_fmt(char *str, size_t size, const char *format, ...);
+int slirp_fmt0(char *str, size_t size, const char *format, ...);
+
#endif
--
2.24.1

12
SPECS/slirp4netns.spec
View File

@ -4,11 +4,13 @@
Name: slirp4netns
Version: 0.4.2
Release: 1.git%{shortcommit0}%{?dist}
Release: 3.git%{shortcommit0}%{?dist}
Summary: slirp for network namespaces
License: GPLv2
URL: %{git0}
Source0: %{git0}/archive/%{commit0}/%{name}-%{shortcommit0}.tar.gz
Patch0: slirp4netns-CVE-2020-7039.patch
Patch1: slirp4netns-CVE-2020-8608.patch
BuildRequires: autoconf
BuildRequires: automake
BuildRequires: gcc
@ -56,6 +58,14 @@ make DESTDIR=%{buildroot} install install-man
%{_mandir}/man1/%{name}.1.gz
%changelog
* Thu Feb 06 2020 Jindrich Novy <jnovy@redhat.com> - 0.4.2-3.git21fdece
- Fix CVE-2020-8608.
- Related: RHELPLAN-25139
* Thu Jan 16 2020 Jindrich Novy <jnovy@redhat.com> - 0.4.2-2.git21fdece
- Fix CVE-2020-7039.
- Related: RHELPLAN-25139
* Sat Dec 07 2019 Jindrich Novy <jnovy@redhat.com> - 0.4.2-1.git21fdece
- update to latest 0.4.2, fixes bug 1763454
- Related: RHELPLAN-25139