ppp: fix CVE-2022-4603

<CVE-2022-4603>
Avoid out-of-range access to packet buffer
Upstream-Status: Backport[https://github.com/ppp-project/ppp/commit/a75fb7b198eed50d769c80c36629f38346882cbf]

(From OE-Core rev: 7f33a49f7aaae67288389eacbe8b13318694e07c)

Signed-off-by:Minjae Kim <flowergom@gmail.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-connectivity/ppp/ppp/CVE-2022-4603.patch

@@ -0,0 +1,50 @@
+From 2aeb41a9a3a43b11b1e46628d0bf98197ff9f141 Mon Sep 17 00:00:00 2001
+From: Paul Mackerras <paulus@ozlabs.org>
+Date: Thu, 29 Dec 2022 18:00:20 +0100
+Subject: [PATCH] pppdump: Avoid out-of-range access to packet buffer
+
+This fixes a potential vulnerability where data is written to spkt.buf
+and rpkt.buf without a check on the array index.  To fix this, we
+check the array index (pkt->cnt) before storing the byte or
+incrementing the count.  This also means we no longer have a potential
+signed integer overflow on the increment of pkt->cnt.
+
+Fortunately, pppdump is not used in the normal process of setting up a
+PPP connection, is not installed setuid-root, and is not invoked
+automatically in any scenario that I am aware of.
+
+Ustream-Status: Backport [https://github.com/ppp-project/ppp/commit/a75fb7b198eed50d769c80c36629f38346882cbf]
+CVE: CVE-2022-4603
+Signed-off-by:Minjae Kim <flowergom@gmail.com>
+---
+ pppdump/pppdump.c | 7 ++++++-
+ 1 file changed, 6 insertions(+), 1 deletion(-)
+
+diff --git a/pppdump/pppdump.c b/pppdump/pppdump.c
+index 87c2e8f..dec4def 100644
+--- a/pppdump/pppdump.c
++++ b/pppdump/pppdump.c
+@@ -296,6 +296,10 @@ dumpppp(f)
+ 			    printf("%s aborted packet:\n     ", dir);
+ 			    q = "    ";
+ 			}
++			if (pkt->cnt >= sizeof(pkt->buf)) {
++			    printf("%s over-long packet truncated:\n     ", dir);
++			    q = "    ";
++			}
+ 			nb = pkt->cnt;
+ 			p = pkt->buf;
+ 			pkt->cnt = 0;
+@@ -399,7 +403,8 @@ dumpppp(f)
+ 			c ^= 0x20;
+ 			pkt->esc = 0;
+ 		    }
+-		    pkt->buf[pkt->cnt++] = c;
++		    if (pkt->cnt < sizeof(pkt->buf))
++			    pkt->buf[pkt->cnt++] = c;
+ 		    break;
+ 		}
+ 	    }
+-- 
+2.25.1
+

meta/recipes-connectivity/ppp/ppp_2.4.7.bb

@@ -34,6 +34,7 @@ SRC_URI = "https://download.samba.org/pub/${BPN}/${BP}.tar.gz \
            file://0001-ppp-Remove-unneeded-include.patch \
            file://ppp-2.4.7-DES-openssl.patch \
            file://0001-pppd-Fix-bounds-check-in-EAP-code.patch \
+           file://CVE-2022-4603.patch \
 "
 
 SRC_URI_append_libc-musl = "\