glibc: backport patches for CVEs in syslog

https://www.qualys.com/2024/01/30/cve-2023-6246/syslog.txt
This commit is contained in:
oreo639 2024-01-31 04:28:56 -08:00
parent caec93c9c6
commit 7863418df8
4 changed files with 320 additions and 1 deletions

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@ -0,0 +1,178 @@
From 23514c72b780f3da097ecf33a793b7ba9c2070d2 Mon Sep 17 00:00:00 2001
From: Arjun Shankar <arjun@redhat.com>
Date: Mon, 15 Jan 2024 17:44:43 +0100
Subject: [PATCH] syslog: Fix heap buffer overflow in __vsyslog_internal
(CVE-2023-6246)
__vsyslog_internal did not handle a case where printing a SYSLOG_HEADER
containing a long program name failed to update the required buffer
size, leading to the allocation and overflow of a too-small buffer on
the heap. This commit fixes that. It also adds a new regression test
that uses glibc.malloc.check.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 6bd0e4efcc78f3c0115e5ea9739a1642807450da)
---
misc/Makefile | 8 ++-
misc/syslog.c | 50 +++++++++++++------
misc/tst-syslog-long-progname.c | 39 +++++++++++++++
.../postclean.req | 0
4 files changed, 82 insertions(+), 15 deletions(-)
create mode 100644 misc/tst-syslog-long-progname.c
create mode 100644 misc/tst-syslog-long-progname.root/postclean.req
diff --git a/misc/Makefile b/misc/Makefile
index fe0d49c1de5..90b31952c59 100644
--- a/misc/Makefile
+++ b/misc/Makefile
@@ -289,7 +289,10 @@ tests-special += $(objpfx)tst-error1-mem.out \
$(objpfx)tst-allocate_once-mem.out
endif
-tests-container := tst-syslog
+tests-container := \
+ tst-syslog \
+ tst-syslog-long-progname \
+ # tests-container
CFLAGS-select.c += -fexceptions -fasynchronous-unwind-tables
CFLAGS-tsearch.c += $(uses-callbacks)
@@ -351,6 +354,9 @@ $(objpfx)tst-allocate_once-mem.out: $(objpfx)tst-allocate_once.out
$(common-objpfx)malloc/mtrace $(objpfx)tst-allocate_once.mtrace > $@; \
$(evaluate-test)
+tst-syslog-long-progname-ENV = GLIBC_TUNABLES=glibc.malloc.check=3 \
+ LD_PRELOAD=libc_malloc_debug.so.0
+
$(objpfx)tst-select: $(librt)
$(objpfx)tst-select-time64: $(librt)
$(objpfx)tst-pselect: $(librt)
diff --git a/misc/syslog.c b/misc/syslog.c
index 1b8cb722c51..814d224a1e9 100644
--- a/misc/syslog.c
+++ b/misc/syslog.c
@@ -124,8 +124,9 @@ __vsyslog_internal (int pri, const char *fmt, va_list ap,
{
/* Try to use a static buffer as an optimization. */
char bufs[1024];
- char *buf = NULL;
- size_t bufsize = 0;
+ char *buf = bufs;
+ size_t bufsize;
+
int msgoff;
int saved_errno = errno;
@@ -177,29 +178,50 @@ __vsyslog_internal (int pri, const char *fmt, va_list ap,
#define SYSLOG_HEADER_WITHOUT_TS(__pri, __msgoff) \
"<%d>: %n", __pri, __msgoff
- int l;
+ int l, vl;
if (has_ts)
l = __snprintf (bufs, sizeof bufs,
SYSLOG_HEADER (pri, timestamp, &msgoff, pid));
else
l = __snprintf (bufs, sizeof bufs,
SYSLOG_HEADER_WITHOUT_TS (pri, &msgoff));
+
+ char *pos;
+ size_t len;
+
if (0 <= l && l < sizeof bufs)
{
- va_list apc;
- va_copy (apc, ap);
+ /* At this point, there is still a chance that we can print the
+ remaining part of the log into bufs and use that. */
+ pos = bufs + l;
+ len = sizeof (bufs) - l;
+ }
+ else
+ {
+ buf = NULL;
+ /* We already know that bufs is too small to use for this log message.
+ The next vsnprintf into bufs is used only to calculate the total
+ required buffer length. We will discard bufs contents and allocate
+ an appropriately sized buffer later instead. */
+ pos = bufs;
+ len = sizeof (bufs);
+ }
- /* Restore errno for %m format. */
- __set_errno (saved_errno);
+ {
+ va_list apc;
+ va_copy (apc, ap);
- int vl = __vsnprintf_internal (bufs + l, sizeof bufs - l, fmt, apc,
- mode_flags);
- if (0 <= vl && vl < sizeof bufs - l)
- buf = bufs;
- bufsize = l + vl;
+ /* Restore errno for %m format. */
+ __set_errno (saved_errno);
- va_end (apc);
- }
+ vl = __vsnprintf_internal (pos, len, fmt, apc, mode_flags);
+
+ if (!(0 <= vl && vl < len))
+ buf = NULL;
+
+ bufsize = l + vl;
+ va_end (apc);
+ }
if (buf == NULL)
{
diff --git a/misc/tst-syslog-long-progname.c b/misc/tst-syslog-long-progname.c
new file mode 100644
index 00000000000..88f37a8a004
--- /dev/null
+++ b/misc/tst-syslog-long-progname.c
@@ -0,0 +1,39 @@
+/* Test heap buffer overflow in syslog with long __progname (CVE-2023-6246)
+ Copyright (C) 2023 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <syslog.h>
+#include <string.h>
+
+extern char * __progname;
+
+static int
+do_test (void)
+{
+ char long_progname[2048];
+
+ memset (long_progname, 'X', sizeof (long_progname) - 1);
+ long_progname[sizeof (long_progname) - 1] = '\0';
+
+ __progname = long_progname;
+
+ syslog (LOG_INFO, "Hello, World!");
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/misc/tst-syslog-long-progname.root/postclean.req b/misc/tst-syslog-long-progname.root/postclean.req
new file mode 100644
index 00000000000..e69de29bb2d

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@ -0,0 +1,103 @@
From d0338312aace5bbfef85e03055e1212dd0e49578 Mon Sep 17 00:00:00 2001
From: Arjun Shankar <arjun@redhat.com>
Date: Mon, 15 Jan 2024 17:44:44 +0100
Subject: [PATCH] syslog: Fix heap buffer overflow in __vsyslog_internal
(CVE-2023-6779)
__vsyslog_internal used the return value of snprintf/vsnprintf to
calculate buffer sizes for memory allocation. If these functions (for
any reason) failed and returned -1, the resulting buffer would be too
small to hold output. This commit fixes that.
All snprintf/vsnprintf calls are checked for negative return values and
the function silently returns upon encountering them.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 7e5a0c286da33159d47d0122007aac016f3e02cd)
---
misc/syslog.c | 39 ++++++++++++++++++++++++++++-----------
1 file changed, 28 insertions(+), 11 deletions(-)
diff --git a/misc/syslog.c b/misc/syslog.c
index 814d224a1e..53440e47ad 100644
--- a/misc/syslog.c
+++ b/misc/syslog.c
@@ -185,11 +185,13 @@ __vsyslog_internal (int pri, const char *fmt, va_list ap,
else
l = __snprintf (bufs, sizeof bufs,
SYSLOG_HEADER_WITHOUT_TS (pri, &msgoff));
+ if (l < 0)
+ goto out;
char *pos;
size_t len;
- if (0 <= l && l < sizeof bufs)
+ if (l < sizeof bufs)
{
/* At this point, there is still a chance that we can print the
remaining part of the log into bufs and use that. */
@@ -215,12 +217,15 @@ __vsyslog_internal (int pri, const char *fmt, va_list ap,
__set_errno (saved_errno);
vl = __vsnprintf_internal (pos, len, fmt, apc, mode_flags);
+ va_end (apc);
+
+ if (vl < 0)
+ goto out;
- if (!(0 <= vl && vl < len))
+ if (vl >= len)
buf = NULL;
bufsize = l + vl;
- va_end (apc);
}
if (buf == NULL)
@@ -231,25 +236,37 @@ __vsyslog_internal (int pri, const char *fmt, va_list ap,
/* Tell the cancellation handler to free this buffer. */
clarg.buf = buf;
+ int cl;
if (has_ts)
- __snprintf (buf, l + 1,
- SYSLOG_HEADER (pri, timestamp, &msgoff, pid));
+ cl = __snprintf (buf, l + 1,
+ SYSLOG_HEADER (pri, timestamp, &msgoff, pid));
else
- __snprintf (buf, l + 1,
- SYSLOG_HEADER_WITHOUT_TS (pri, &msgoff));
+ cl = __snprintf (buf, l + 1,
+ SYSLOG_HEADER_WITHOUT_TS (pri, &msgoff));
+ if (cl != l)
+ goto out;
va_list apc;
va_copy (apc, ap);
- __vsnprintf_internal (buf + l, bufsize - l + 1, fmt, apc,
- mode_flags);
+ cl = __vsnprintf_internal (buf + l, bufsize - l + 1, fmt, apc,
+ mode_flags);
va_end (apc);
+
+ if (cl != vl)
+ goto out;
}
else
{
+ int bl;
/* Nothing much to do but emit an error message. */
- bufsize = __snprintf (bufs, sizeof bufs,
- "out of memory[%d]", __getpid ());
+ bl = __snprintf (bufs, sizeof bufs,
+ "out of memory[%d]", __getpid ());
+ if (bl < 0 || bl >= sizeof bufs)
+ goto out;
+
+ bufsize = bl;
buf = bufs;
+ msgoff = 0;
}
}

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@ -0,0 +1,38 @@
From d37c2b20a4787463d192b32041c3406c2bd91de0 Mon Sep 17 00:00:00 2001
From: Arjun Shankar <arjun@redhat.com>
Date: Mon, 15 Jan 2024 17:44:45 +0100
Subject: [PATCH] syslog: Fix integer overflow in __vsyslog_internal
(CVE-2023-6780)
__vsyslog_internal calculated a buffer size by adding two integers, but
did not first check if the addition would overflow. This commit fixes
that.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit ddf542da94caf97ff43cc2875c88749880b7259b)
---
misc/syslog.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/misc/syslog.c b/misc/syslog.c
index 53440e47ad..4af87f54fd 100644
--- a/misc/syslog.c
+++ b/misc/syslog.c
@@ -41,6 +41,7 @@ static char sccsid[] = "@(#)syslog.c 8.4 (Berkeley) 3/18/94";
#include <sys/uio.h>
#include <sys/un.h>
#include <syslog.h>
+#include <limits.h>
static int LogType = SOCK_DGRAM; /* type of socket connection */
static int LogFile = -1; /* fd for log */
@@ -219,7 +220,7 @@ __vsyslog_internal (int pri, const char *fmt, va_list ap,
vl = __vsnprintf_internal (pos, len, fmt, apc, mode_flags);
va_end (apc);
- if (vl < 0)
+ if (vl < 0 || vl >= INT_MAX - l)
goto out;
if (vl >= len)

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@ -1,7 +1,7 @@
# Template file for 'glibc'
pkgname=glibc
version=2.38
revision=4
revision=5
bootstrap=yes
short_desc="GNU C library"
maintainer="Enno Boland <gottox@voidlinux.org>"