commit f7d3dbb82e7ed94ccbf10cf70a3c7b3f3aaef1a1
author Phil Sutter <phil@nwl.cc> Thu Dec 05 13:57:18 2019 +0100
committer Phil Sutter <phil@nwl.cc> Fri Dec 06 12:12:08 2019 +0100
tree a4448c3bbd2ace81e937aad8b2f67e60b7c80388
parent 28c16371cdad16707674450b59919e3d97185694

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.

libxtables/xtables.c

diff --git a/libxtables/xtables.c b/libxtables/xtables.c
index 895f698..777c2b0 100644
--- a/libxtables/xtables.c
+++ b/libxtables/xtables.c
@@ -856,7 +856,8 @@
 
 	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);