From: Phil Sutter <phil@nwl.cc>
Date: Thu, 5 Dec 2019 12:57:18 +0000 (+0100)
Subject: libxtables: Avoid buffer overrun in xtables_compatible_revision()
X-Git-Tag: v1.8.5~77
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f7d3dbb82e7ed94ccbf10cf70a3c7b3f3aaef1a1;p=thirdparty%2Fiptables.git

libxtables: Avoid buffer overrun in xtables_compatible_revision()

The function is exported and accepts arbitrary strings as input. Calling
strcpy() without length checks is not OK.
---

diff --git a/libxtables/xtables.c b/libxtables/xtables.c
index 895f6988..777c2b08 100644
--- a/libxtables/xtables.c
+++ b/libxtables/xtables.c
@@ -856,7 +856,8 @@ int xtables_compatible_revision(const char *name, uint8_t revision, int opt)
 
 	xtables_load_ko(xtables_modprobe_program, true);
 
-	strcpy(rev.name, name);
+	strncpy(rev.name, name, XT_EXTENSION_MAXNAMELEN - 1);
+	rev.name[XT_EXTENSION_MAXNAMELEN - 1] = '\0';
 	rev.revision = revision;
 
 	max_rev = getsockopt(sockfd, afinfo->ipproto, opt, &rev, &s);