netdev - [PATCH iproute2] iproute: fix printing resolved localhost

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <20210228124520.30005-1-bluca@debian.org>
Date:   Sun, 28 Feb 2021 12:45:20 +0000
From:   Luca Boccassi <bluca@...ian.org>
To:     netdev@...r.kernel.org
Subject: [PATCH iproute2] iproute: fix printing resolved localhost

format_host_rta_r might return a cached hostname
via its return value and not use the input buffer.

Before:

$ ip -resolve -6 route
 dev lo proto kernel metric 256 pref medium

After:

$ ip/ip -resolve -6 route
localhost dev lo proto kernel metric 256 pref medium

Bug-Debian: https://bugs.debian.org/983591

Reported-by: Axel Scheepers <axel.scheepers76@...il.com>
Signed-off-by: Luca Boccassi <bluca@...ian.org>
---
 ip/iproute.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/ip/iproute.c b/ip/iproute.c
index 291f1a58..5853f026 100644
--- a/ip/iproute.c
+++ b/ip/iproute.c
@@ -796,9 +796,10 @@ int print_route(struct nlmsghdr *n, void *arg)
 				 "%s/%u", rt_addr_n2a_rta(family, tb[RTA_DST]),
 				 r->rtm_dst_len);
 		} else {
-			format_host_rta_r(family, tb[RTA_DST],
+			const char *hostname = format_host_rta_r(family, tb[RTA_DST],
 					  b1, sizeof(b1));
-
+			if (hostname)
+				strncpy(b1, hostname, sizeof(b1) - 1);
 		}
 	} else if (r->rtm_dst_len) {
 		snprintf(b1, sizeof(b1), "0/%d ", r->rtm_dst_len);
@@ -818,8 +819,10 @@ int print_route(struct nlmsghdr *n, void *arg)
 				 rt_addr_n2a_rta(family, tb[RTA_SRC]),
 				 r->rtm_src_len);
 		} else {
-			format_host_rta_r(family, tb[RTA_SRC],
+			const char *hostname = format_host_rta_r(family, tb[RTA_SRC],
 					  b1, sizeof(b1));
+			if (hostname)
+				strncpy(b1, hostname, sizeof(b1) - 1);
 		}
 		print_color_string(PRINT_ANY, color,
 				   "from", "from %s ", b1);
-- 
2.30.1