Revision eb35bdd7bca29a13c8ecd44e6fd747a84ce675db authored by Will Deacon on 11 September 2014, 13:38:16 UTC, committed by Will Deacon on 11 September 2014, 17:34:58 UTC
Nathan reports that we leak TLS information from the parent context
during an exec, as we don't clear the TLS registers when flushing the
thread state.
This patch updates the flushing code so that we:
(1) Unconditionally zero the tpidr_el0 register (since this is fully
context switched for native tasks and zeroed for compat tasks)
(2) Zero the tp_value state in thread_info before clearing the
tpidrr0_el0 register for compat tasks (since this is only writable
by the set_tls compat syscall and therefore not fully switched).
A missing compiler barrier is also added to the compat set_tls syscall.
Cc: <stable@vger.kernel.org>
Acked-by: Nathan Lynch <Nathan_Lynch@mentor.com>
Reported-by: Nathan Lynch <Nathan_Lynch@mentor.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
1 parent 3d8afe3
xfrm6_mode_tunnel.c
/*
* xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6.
*
* Copyright (C) 2002 USAGI/WIDE Project
* Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
*/
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/stringify.h>
#include <net/dsfield.h>
#include <net/dst.h>
#include <net/inet_ecn.h>
#include <net/ip6_route.h>
#include <net/ipv6.h>
#include <net/xfrm.h>
static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
{
const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
IP6_ECN_set_ce(inner_iph);
}
/* Add encapsulation header.
*
* The top IP header will be constructed per RFC 2401.
*/
static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
struct ipv6hdr *top_iph;
int dsfield;
skb_set_network_header(skb, -x->props.header_len);
skb->mac_header = skb->network_header +
offsetof(struct ipv6hdr, nexthdr);
skb->transport_header = skb->network_header + sizeof(*top_iph);
top_iph = ipv6_hdr(skb);
top_iph->version = 6;
memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
sizeof(top_iph->flow_lbl));
top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);
if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
dsfield = 0;
else
dsfield = XFRM_MODE_SKB_CB(skb)->tos;
dsfield = INET_ECN_encapsulate(dsfield, XFRM_MODE_SKB_CB(skb)->tos);
if (x->props.flags & XFRM_STATE_NOECN)
dsfield &= ~INET_ECN_MASK;
ipv6_change_dsfield(top_iph, 0, dsfield);
top_iph->hop_limit = ip6_dst_hoplimit(dst->child);
top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
return 0;
}
#define for_each_input_rcu(head, handler) \
for (handler = rcu_dereference(head); \
handler != NULL; \
handler = rcu_dereference(handler->next))
static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
int err = -EINVAL;
if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
goto out;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto out;
err = skb_unclone(skb, GFP_ATOMIC);
if (err)
goto out;
if (x->props.flags & XFRM_STATE_DECAP_DSCP)
ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
ipipv6_hdr(skb));
if (!(x->props.flags & XFRM_STATE_NOECN))
ipip6_ecn_decapsulate(skb);
skb_reset_network_header(skb);
skb_mac_header_rebuild(skb);
err = 0;
out:
return err;
}
static struct xfrm_mode xfrm6_tunnel_mode = {
.input2 = xfrm6_mode_tunnel_input,
.input = xfrm_prepare_input,
.output2 = xfrm6_mode_tunnel_output,
.output = xfrm6_prepare_output,
.owner = THIS_MODULE,
.encap = XFRM_MODE_TUNNEL,
.flags = XFRM_MODE_FLAG_TUNNEL,
};
static int __init xfrm6_mode_tunnel_init(void)
{
return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
}
static void __exit xfrm6_mode_tunnel_exit(void)
{
int err;
err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
BUG_ON(err);
}
module_init(xfrm6_mode_tunnel_init);
module_exit(xfrm6_mode_tunnel_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);
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