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Commit 26711a79 authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

userns: xt_owner: Add basic user namespace support. 



- Only allow adding matches from the initial user namespace
- Add the appropriate conversion functions to handle matches
  against sockets in other user namespaces.

Cc: Jan Engelhardt <jengelh@medozas.de>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
parent da742808

init/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -943,7 +943,6 @@ config UIDGID_CONVERTED 


	# Networking

	depends on NET_9P = n

	depends on NETFILTER_XT_MATCH_OWNER = n

	depends on AF_RXRPC = n

	depends on NET_KEY = n

	depends on DNS_RESOLVER = n

net/netfilter/xt_owner.c

+24 −6
Original line number Diff line number Diff line
@@ -17,6 +17,17 @@ 
#include <linux/netfilter/x_tables.h>

#include <linux/netfilter/xt_owner.h>



static int owner_check(const struct xt_mtchk_param *par)

{

	struct xt_owner_match_info *info = par->matchinfo;



	/* For now only allow adding matches from the initial user namespace */

	if ((info->match & (XT_OWNER_UID|XT_OWNER_GID)) &&

	    (current_user_ns() != &init_user_ns))

		return -EINVAL;

	return 0;

}



static bool

owner_mt(const struct sk_buff *skb, struct xt_action_param *par)

{
@@ -37,17 +48,23 @@ owner_mt(const struct sk_buff *skb, struct xt_action_param *par) 
		return ((info->match ^ info->invert) &

		       (XT_OWNER_UID | XT_OWNER_GID)) == 0;



	if (info->match & XT_OWNER_UID)

		if ((filp->f_cred->fsuid >= info->uid_min &&

		    filp->f_cred->fsuid <= info->uid_max) ^

	if (info->match & XT_OWNER_UID) {

		kuid_t uid_min = make_kuid(&init_user_ns, info->uid_min);

		kuid_t uid_max = make_kuid(&init_user_ns, info->uid_max);

		if ((uid_gte(filp->f_cred->fsuid, uid_min) &&

		     uid_lte(filp->f_cred->fsuid, uid_max)) ^

		    !(info->invert & XT_OWNER_UID))

			return false;

	}



	if (info->match & XT_OWNER_GID)

		if ((filp->f_cred->fsgid >= info->gid_min &&

		    filp->f_cred->fsgid <= info->gid_max) ^

	if (info->match & XT_OWNER_GID) {

		kgid_t gid_min = make_kgid(&init_user_ns, info->gid_min);

		kgid_t gid_max = make_kgid(&init_user_ns, info->gid_max);

		if ((gid_gte(filp->f_cred->fsgid, gid_min) &&

		     gid_lte(filp->f_cred->fsgid, gid_max)) ^

		    !(info->invert & XT_OWNER_GID))

			return false;

	}



	return true;

}
@@ -56,6 +73,7 @@ static struct xt_match owner_mt_reg __read_mostly = { 
	.name       = "owner",

	.revision   = 1,

	.family     = NFPROTO_UNSPEC,

	.checkentry = owner_check,

	.match      = owner_mt,

	.matchsize  = sizeof(struct xt_owner_match_info),

	.hooks      = (1 << NF_INET_LOCAL_OUT) |