From 7eb9e4880c769ae6c951939308d4d32cabfcfac8 Mon Sep 17 00:00:00 2001
From: emaste <emaste@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Date: Wed, 5 Feb 2020 18:26:50 +0000
Subject: [PATCH] MFC r357212: libfetch: fix urldecode buffer overrun

Reported by:	Duncan Overbruck
Security:	CVE-2020-7450


git-svn-id: svn://svn.freebsd.org/base/stable/10@357582 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
---
 lib/libfetch/fetch.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/libfetch/fetch.c b/lib/libfetch/fetch.c
index f2510831c..849f0fad9 100644
--- a/lib/libfetch/fetch.c
+++ b/lib/libfetch/fetch.c
@@ -328,6 +328,8 @@ fetch_pctdecode(char *dst, const char *src, size_t dlen)
 		}
 		if (dlen-- > 0)
 			*dst++ = c;
+		else
+			return (NULL);
 	}
 	return (s);
 }
@@ -375,11 +377,15 @@ fetchParseURL(const char *URL)
 	if (p && *p == '@') {
 		/* username */
 		q = fetch_pctdecode(u->user, URL, URL_USERLEN);
+		if (q == NULL)
+			goto ouch;
 
 		/* password */
-		if (*q == ':')
+		if (*q == ':') {
 			q = fetch_pctdecode(u->pwd, q + 1, URL_PWDLEN);
-
+			if (q == NULL)
+				goto ouch;
+		}
 		p++;
 	} else {
 		p = URL;
-- 
2.42.0