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Revision 78c906e430b13d30a8cfbdef4ccbbe1686841a9e authored by Vlad Buslov on 31 August 2020, 13:17:29 UTC, committed by Saeed Mahameed on 05 November 2020, 20:17:05 UTC 
net/mlx5e: Protect encap route dev from concurrent release
 
In functions mlx5e_route_lookup_ipv{4|6}() route_dev can be arbitrary net
device and not necessary mlx5 eswitch port representor. As such, in order
to ensure that route_dev is not destroyed concurrent the code needs either
explicitly take reference to the device before releasing reference to
rtable instance or ensure that caller holds rtnl lock. First approach is
chosen as a fix since rtnl lock dependency was intentionally removed from
mlx5 TC layer.

To prevent unprotected usage of route_dev in encap code take a reference to
the device before releasing rt. Don't save direct pointer to the device in
mlx5_encap_entry structure and use ifindex instead. Modify users of
route_dev pointer to properly obtain the net device instance from its
ifindex.

Fixes: 61086f391044 ("net/mlx5e: Protect encap hash table with mutex")
Fixes: 6707f74be862 ("net/mlx5e: Update hw flows when encap source mac changed")
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
1 parent e68e28b
Raw File
xfrm4_tunnel.c 
// SPDX-License-Identifier: GPL-2.0-only
/* xfrm4_tunnel.c: Generic IP tunnel transformer.
 *
 * Copyright (C) 2003 David S. Miller (davem@redhat.com)
 */

#define pr_fmt(fmt) "IPsec: " fmt

#include <linux/skbuff.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <net/xfrm.h>
#include <net/ip.h>
#include <net/protocol.h>

static int ipip_output(struct xfrm_state *x, struct sk_buff *skb)
{
	skb_push(skb, -skb_network_offset(skb));
	return 0;
}

static int ipip_xfrm_rcv(struct xfrm_state *x, struct sk_buff *skb)
{
	return ip_hdr(skb)->protocol;
}

static int ipip_init_state(struct xfrm_state *x)
{
	if (x->props.mode != XFRM_MODE_TUNNEL)
		return -EINVAL;

	if (x->encap)
		return -EINVAL;

	x->props.header_len = sizeof(struct iphdr);

	return 0;
}

static void ipip_destroy(struct xfrm_state *x)
{
}

static const struct xfrm_type ipip_type = {
	.description	= "IPIP",
	.owner		= THIS_MODULE,
	.proto	     	= IPPROTO_IPIP,
	.init_state	= ipip_init_state,
	.destructor	= ipip_destroy,
	.input		= ipip_xfrm_rcv,
	.output		= ipip_output
};

static int xfrm_tunnel_rcv(struct sk_buff *skb)
{
	return xfrm4_rcv_spi(skb, IPPROTO_IPIP, ip_hdr(skb)->saddr);
}

static int xfrm_tunnel_err(struct sk_buff *skb, u32 info)
{
	return -ENOENT;
}

static struct xfrm_tunnel xfrm_tunnel_handler __read_mostly = {
	.handler	=	xfrm_tunnel_rcv,
	.err_handler	=	xfrm_tunnel_err,
	.priority	=	3,
};

#if IS_ENABLED(CONFIG_IPV6)
static struct xfrm_tunnel xfrm64_tunnel_handler __read_mostly = {
	.handler	=	xfrm_tunnel_rcv,
	.err_handler	=	xfrm_tunnel_err,
	.priority	=	2,
};
#endif

static int __init ipip_init(void)
{
	if (xfrm_register_type(&ipip_type, AF_INET) < 0) {
		pr_info("%s: can't add xfrm type\n", __func__);
		return -EAGAIN;
	}

	if (xfrm4_tunnel_register(&xfrm_tunnel_handler, AF_INET)) {
		pr_info("%s: can't add xfrm handler for AF_INET\n", __func__);
		xfrm_unregister_type(&ipip_type, AF_INET);
		return -EAGAIN;
	}
#if IS_ENABLED(CONFIG_IPV6)
	if (xfrm4_tunnel_register(&xfrm64_tunnel_handler, AF_INET6)) {
		pr_info("%s: can't add xfrm handler for AF_INET6\n", __func__);
		xfrm4_tunnel_deregister(&xfrm_tunnel_handler, AF_INET);
		xfrm_unregister_type(&ipip_type, AF_INET);
		return -EAGAIN;
	}
#endif
	return 0;
}

static void __exit ipip_fini(void)
{
#if IS_ENABLED(CONFIG_IPV6)
	if (xfrm4_tunnel_deregister(&xfrm64_tunnel_handler, AF_INET6))
		pr_info("%s: can't remove xfrm handler for AF_INET6\n",
			__func__);
#endif
	if (xfrm4_tunnel_deregister(&xfrm_tunnel_handler, AF_INET))
		pr_info("%s: can't remove xfrm handler for AF_INET\n",
			__func__);
	xfrm_unregister_type(&ipip_type, AF_INET);
}

module_init(ipip_init);
module_exit(ipip_fini);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_IPIP);
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