From 5fe54ca701a38e283faf840903e9ed20eba8a6f4 Mon Sep 17 00:00:00 2001
From: Phil Sutter <phil@nwl.cc>
Date: Thu, 5 Dec 2019 16:01:29 +0100
Subject: [PATCH] xtables-translate: Guard strcpy() call in xlate_ifname()
The function potentially fed overlong strings to strcpy(). Given that
everything needed to avoid this is there, reorder code a bit to prevent
those inputs, too.
Fixes: 0ddd663e9c167 ("iptables-translate: add in/out ifname wildcard match translation to nft")
(cherry picked from commit 2861bdbbf062071487a49103513d129ce40e2652)
Signed-off-by: Phil Sutter <psutter@redhat.com>
---
iptables/xtables-translate.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/iptables/xtables-translate.c b/iptables/xtables-translate.c
index a42c60a3b64c6..77a186b905d73 100644
--- a/iptables/xtables-translate.c
+++ b/iptables/xtables-translate.c
@@ -32,14 +32,13 @@
void xlate_ifname(struct xt_xlate *xl, const char *nftmeta, const char *ifname,
bool invert)
{
+ int ifaclen = strlen(ifname);
char iface[IFNAMSIZ];
- int ifaclen;
- if (ifname[0] == '\0')
+ if (ifaclen < 1 || ifaclen >= IFNAMSIZ)
return;
strcpy(iface, ifname);
- ifaclen = strlen(iface);
if (iface[ifaclen - 1] == '+')
iface[ifaclen - 1] = '*';
--
2.24.0