Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 42eab94f authored by Vasiliy Kulikov's avatar Vasiliy Kulikov Committed by Patrick McHardy
Browse files

netfilter: arp_tables: fix infoleak to userspace 



Structures ipt_replace, compat_ipt_replace, and xt_get_revision are
copied from userspace.  Fields of these structs that are
zero-terminated strings are not checked.  When they are used as argument
to a format string containing "%s" in request_module(), some sensitive
information is leaked to userspace via argument of spawned modprobe
process.

The first bug was introduced before the git epoch;  the second is
introduced by 6b7d31fc (v2.6.15-rc1);  the third is introduced by
6b7d31fc (v2.6.15-rc1).  To trigger the bug one should have
CAP_NET_ADMIN.

Signed-off-by: default avatarVasiliy Kulikov <segoon@openwall.com>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 4656c4d6

net/ipv4/netfilter/arp_tables.c

+3 −0
Original line number Diff line number Diff line
@@ -1066,6 +1066,7 @@ static int do_replace(struct net *net, const void __user *user, 
	/* overflow check */

	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))

		return -ENOMEM;

	tmp.name[sizeof(tmp.name)-1] = 0;



	newinfo = xt_alloc_table_info(tmp.size);

	if (!newinfo)
@@ -1488,6 +1489,7 @@ static int compat_do_replace(struct net *net, void __user *user, 
		return -ENOMEM;

	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))

		return -ENOMEM;

	tmp.name[sizeof(tmp.name)-1] = 0;



	newinfo = xt_alloc_table_info(tmp.size);

	if (!newinfo)
@@ -1740,6 +1742,7 @@ static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len 
			ret = -EFAULT;

			break;

		}

		rev.name[sizeof(rev.name)-1] = 0;



		try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name,

							 rev.revision, 1, &ret),