connman: Fix CVE-2023-28488 DoS in client.c

Avoid overwriting the read packet length after the initial test. Thus
move all the length checks which depends on the total length first
and do not use the total lenght from the IP packet afterwards.

Fixes CVE-2023-28488

Reported by Polina Smirnova <moe.hwr@gmail.com>

(From OE-Core rev: 47a9ae5592392bd10740e4571b06c8c739705058)

Signed-off-by: Ashish Sharma <asharma@mvista.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 55 insertions, 0 deletions

diff --git a/meta/recipes-connectivity/connman/connman/CVE-2023-28488.patch b/meta/recipes-connectivity/connman/connman/CVE-2023-28488.patch
new file mode 100644
index 0000000000..ea1601cc04
--- /dev/null
+++ b/meta/recipes-connectivity/connman/connman/CVE-2023-28488.patch
@@ -0,0 +1,54 @@
+From 99e2c16ea1cced34a5dc450d76287a1c3e762138 Mon Sep 17 00:00:00 2001
+From: Daniel Wagner <wagi@monom.org>
+Date: Tue, 11 Apr 2023 08:12:56 +0200
+Subject: gdhcp: Verify and sanitize packet length first
+
+Upstream-Status: Backport [https://git.kernel.org/pub/scm/network/connman/connman.git/patch/?id=99e2c16ea1cced34a5dc450d76287a1c3e762138]
+CVE: CVE-2023-28488
+Signed-off-by: Ashish Sharma <asharma@mvista.com>
+
+ gdhcp/client.c | 16 +++++++++-------
+ 1 file changed, 9 insertions(+), 7 deletions(-)
+
+diff --git a/gdhcp/client.c b/gdhcp/client.c
+index 7efa7e45..82017692 100644
+--- a/gdhcp/client.c
++++ b/gdhcp/client.c
+@@ -1319,9 +1319,9 @@ static bool sanity_check(struct ip_udp_dhcp_packet *packet, int bytes)
+ static int dhcp_recv_l2_packet(struct dhcp_packet *dhcp_pkt, int fd,
+                                struct sockaddr_in *dst_addr)
+ {
+-       int bytes;
+        struct ip_udp_dhcp_packet packet;
+        uint16_t check;
++       int bytes, tot_len;
+ 
+        memset(&packet, 0, sizeof(packet));
+ 
+@@ -1329,15 +1329,17 @@ static int dhcp_recv_l2_packet(struct dhcp_packet *dhcp_pkt, int fd,
+        if (bytes < 0)
+                return -1;
+ 
+-       if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp)))
+-               return -1;
+-
+-       if (bytes < ntohs(packet.ip.tot_len))
++       tot_len = ntohs(packet.ip.tot_len);
++       if (bytes > tot_len) {
++               /* ignore any extra garbage bytes */
++               bytes = tot_len;
++       } else if (bytes < tot_len) {
+                /* packet is bigger than sizeof(packet), we did partial read */
+                return -1;
++       }
+ 
+-       /* ignore any extra garbage bytes */
+-       bytes = ntohs(packet.ip.tot_len);
++       if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp)))
++               return -1;
+ 
+        if (!sanity_check(&packet, bytes))
+                return -1;
+-- 
+cgit 
+
diff --git a/meta/recipes-connectivity/connman/connman_1.37.bb b/meta/recipes-connectivity/connman/connman_1.37.bb
index 73d7f7527e..8062a094d3 100644
--- a/meta/recipes-connectivity/connman/connman_1.37.bb
+++ b/meta/recipes-connectivity/connman/connman_1.37.bb
@@ -14,6 +14,7 @@ SRC_URI  = "${KERNELORG_MIRROR}/linux/network/${BPN}/${BP}.tar.xz \
             file://CVE-2022-23098.patch \
             file://CVE-2022-32292.patch \
              file://CVE-2022-32293.patch \
+            file://CVE-2023-28488.patch \
 "
 
 SRC_URI_append_libc-musl = " file://0002-resolve-musl-does-not-implement-res_ninit.patch"