NetCube-Systems-Austria/kumquat-buildroot
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

dhcp: add upstream security fixes

Browse Source 
CVE-2018-5732: The DHCP client incorrectly handled certain malformed
responses. A remote attacker could use this issue to cause the DHCP
client to crash, resulting in a denial of service, or possibly execute
arbitrary code. In the default installation, attackers would be isolated
by the dhclient AppArmor profile.

CVE-2018-5733: The DHCP server incorrectly handled reference counting. A
remote attacker could possibly use this issue to cause the DHCP server
to crash, resulting in a denial of service.

Both issues are fixed in version 4.4.1. But we are close to release, so
backport the fixes instead of bumping version.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
This commit is contained in:
Baruch Siach 2018-03-03 21:43:56 +02:00 committed by Peter Korsgaard
parent 00fc361b0a
commit 047cec5993
2 changed files with 99 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

59
package/dhcp/0003-Correct-buffer-overrun-in-pretty_print_option.patch Normal file
View File

@ -0,0 +1,59 @@
From b8c29336bd5401a5f962bc6ddfa4ebb6f0274f3c Mon Sep 17 00:00:00 2001
From: Thomas Markwalder <tmark@isc.org>
Date: Sat, 10 Feb 2018 12:15:27 -0500
Subject: [PATCH 1/2] Correct buffer overrun in pretty_print_option
Merges in rt47139.
[baruch: drop RELNOTES and test; address CVE-2018-5732]
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
Upstream status: backported from commit c5931725b48
---
common/options.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/common/options.c b/common/options.c
index 5547287fb6e5..2ed6b16c6412 100644
--- a/common/options.c
+++ b/common/options.c
@@ -1758,7 +1758,8 @@ format_min_length(format, oc)
/* Format the specified option so that a human can easily read it. */
-
+/* Maximum pretty printed size */
+#define MAX_OUTPUT_SIZE 32*1024
const char *pretty_print_option (option, data, len, emit_commas, emit_quotes)
struct option *option;
const unsigned char *data;
@@ -1766,8 +1767,9 @@ const char *pretty_print_option (option, data, len, emit_commas, emit_quotes)
int emit_commas;
int emit_quotes;
{
- static char optbuf [32768]; /* XXX */
- static char *endbuf = &optbuf[sizeof(optbuf)];
+ /* We add 128 byte pad so we don't have to add checks everywhere. */
+ static char optbuf [MAX_OUTPUT_SIZE + 128]; /* XXX */
+ static char *endbuf = optbuf + MAX_OUTPUT_SIZE;
int hunksize = 0;
int opthunk = 0;
int hunkinc = 0;
@@ -2193,7 +2195,14 @@ const char *pretty_print_option (option, data, len, emit_commas, emit_quotes)
log_error ("Unexpected format code %c",
fmtbuf [j]);
}
+
op += strlen (op);
+ if (op >= endbuf) {
+ log_error ("Option data exceeds"
+ " maximum size %d", MAX_OUTPUT_SIZE);
+ return ("<error>");
+ }
+
if (dp == data + len)
break;
if (j + 1 < numelem && comma != ':')
--
2.16.1

40
package/dhcp/0004-Corrected-refcnt-loss-in-option-parsing.patch Normal file
View File

@ -0,0 +1,40 @@
From 93b5b67dd31b9efcbfaabc2df1e1d9d164a5e04a Mon Sep 17 00:00:00 2001
From: Thomas Markwalder <tmark@isc.org>
Date: Fri, 9 Feb 2018 14:46:08 -0500
Subject: [PATCH 2/2] Corrected refcnt loss in option parsing
Merges in 47140.
[baruch: drop RELNOTES and tests; address CVE-2018-5733]
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
Upstream status: backported from commit 197b26f25309
---
common/options.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/common/options.c b/common/options.c
index 2ed6b16c6412..25b29a6be7bb 100644
--- a/common/options.c
+++ b/common/options.c
@@ -3,7 +3,7 @@
DHCP options parsing and reassembly. */
/*
- * Copyright (c) 2004-2017 by Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (c) 2004-2018 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1995-2003 by Internet Software Consortium
*
* Permission to use, copy, modify, and distribute this software for any
@@ -177,6 +177,8 @@ int parse_option_buffer (options, buffer, length, universe)
/* If the length is outrageous, the options are bad. */
if (offset + len > length) {
+ /* Avoid reference count overflow */
+ option_dereference(&option, MDL);
reason = "option length exceeds option buffer length";
bogus:
log_error("parse_option_buffer: malformed option "
--
2.16.1