[Buildroot] [PATCH v1 2/2] package/busybox: udhcp CVE-2019-5747 patch

jared.bents at rockwellcollins.com jared.bents at rockwellcollins.com
Wed Mar 6 14:22:31 UTC 2019


From: Jared Bents <jared.bents at rockwellcollins.com>

Patch to resolve CVE-2019-5747 which affects versions prior
to 1.30.0

More information can be found at:
https://nvd.nist.gov/vuln/detail/CVE-2019-5747

This applies to both master and 2019.02

Signed-off-by: Jared Bents <jared.bents at rockwellcollins.com>
---
 ...HCP_SUBNET-ensure-it-is-4-bytes-long.patch | 57 +++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 package/busybox/0005-udhcpc-when-decoding-DHCP_SUBNET-ensure-it-is-4-bytes-long.patch

diff --git a/package/busybox/0005-udhcpc-when-decoding-DHCP_SUBNET-ensure-it-is-4-bytes-long.patch b/package/busybox/0005-udhcpc-when-decoding-DHCP_SUBNET-ensure-it-is-4-bytes-long.patch
new file mode 100644
index 0000000000..f81f02b30c
--- /dev/null
+++ b/package/busybox/0005-udhcpc-when-decoding-DHCP_SUBNET-ensure-it-is-4-bytes-long.patch
@@ -0,0 +1,57 @@
+From 74d9f1ba37010face4bd1449df4d60dd84450b06 Mon Sep 17 00:00:00 2001
+From: Denys Vlasenko <vda.linux at googlemail.com>
+Date: Mon, 7 Jan 2019 15:33:42 +0100
+Subject: udhcpc: when decoding DHCP_SUBNET, ensure it is 4 bytes long
+
+function                                             old     new   delta
+udhcp_run_script                                     795     801      +6
+
+Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
+---
+ networking/udhcp/common.c | 2 +-
+ networking/udhcp/common.h | 2 +-
+ networking/udhcp/dhcpc.c  | 2 +-
+ 3 files changed, 3 insertions(+), 3 deletions(-)
+
+diff --git a/networking/udhcp/common.c b/networking/udhcp/common.c
+index 4c2221b77..fc4de5716 100644
+--- a/networking/udhcp/common.c
++++ b/networking/udhcp/common.c
+@@ -302,7 +302,7 @@ uint8_t* FAST_FUNC udhcp_get_option32(struct dhcp_packet *packet, int code)
+ {
+ 	uint8_t *r = udhcp_get_option(packet, code);
+ 	if (r) {
+-		if (r[-1] != 4)
++		if (r[-OPT_DATA + OPT_LEN] != 4)
+ 			r = NULL;
+ 	}
+ 	return r;
+diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h
+index 9511152ff..62f9a2a4a 100644
+--- a/networking/udhcp/common.h
++++ b/networking/udhcp/common.h
+@@ -119,7 +119,7 @@ enum {
+ //#define DHCP_TIME_SERVER      0x04 /* RFC 868 time server (32-bit, 0 = 1.1.1900) */
+ //#define DHCP_NAME_SERVER      0x05 /* IEN 116 _really_ ancient kind of NS */
+ //#define DHCP_DNS_SERVER       0x06
+-//#define DHCP_LOG_SERVER       0x07 /* port 704 UDP log (not syslog)
++//#define DHCP_LOG_SERVER       0x07 /* port 704 UDP log (not syslog) */
+ //#define DHCP_COOKIE_SERVER    0x08 /* "quote of the day" server */
+ //#define DHCP_LPR_SERVER       0x09
+ #define DHCP_HOST_NAME          0x0c /* 12: either client informs server or server gives name to client */
+diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
+index 5b3fd531c..dcec8cdfd 100644
+--- a/networking/udhcp/dhcpc.c
++++ b/networking/udhcp/dhcpc.c
+@@ -531,7 +531,7 @@ static char **fill_envp(struct dhcp_packet *packet)
+ 		temp = udhcp_get_option(packet, code);
+ 		*curr = xmalloc_optname_optval(temp, &dhcp_optflags[i], opt_name);
+ 		putenv(*curr++);
+-		if (code == DHCP_SUBNET) {
++		if (code == DHCP_SUBNET && temp[-OPT_DATA + OPT_LEN] == 4) {
+ 			/* Subnet option: make things like "$ip/$mask" possible */
+ 			uint32_t subnet;
+ 			move_from_unaligned32(subnet, temp);
+-- 
+cgit v1.2.1
+
-- 
2.18.0



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