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Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/calipso.c3
-rw-r--r--net/ipv6/ip6_gre.c15
-rw-r--r--net/ipv6/route.c13
3 files changed, 26 insertions, 5 deletions
diff --git a/net/ipv6/calipso.c b/net/ipv6/calipso.c
index df1986973430..21f6ed126253 100644
--- a/net/ipv6/calipso.c
+++ b/net/ipv6/calipso.c
@@ -1342,7 +1342,8 @@ static int calipso_skbuff_setattr(struct sk_buff *skb,
/* At this point new_end aligns to 4n, so (new_end & 4) pads to 8n */
pad = ((new_end & 4) + (end & 7)) & 7;
len_delta = new_end - (int)end + pad;
- ret_val = skb_cow(skb, skb_headroom(skb) + len_delta);
+ ret_val = skb_cow(skb,
+ skb_headroom(skb) + (len_delta > 0 ? len_delta : 0));
if (ret_val < 0)
return ret_val;
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index c82a75510c0e..d19d86ed4376 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -535,6 +535,10 @@ static int ip6erspan_rcv(struct sk_buff *skb,
if (!tun_dst)
return PACKET_REJECT;
+ /* MUST set options_len before referencing options */
+ info = &tun_dst->u.tun_info;
+ info->options_len = sizeof(*md);
+
/* skb can be uncloned in __iptunnel_pull_header, so
* old pkt_md is no longer valid and we need to reset
* it
@@ -543,7 +547,6 @@ static int ip6erspan_rcv(struct sk_buff *skb,
skb_network_header_len(skb);
pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
sizeof(*ershdr));
- info = &tun_dst->u.tun_info;
md = ip_tunnel_info_opts(info);
md->version = ver;
md2 = &md->u.md2;
@@ -551,7 +554,6 @@ static int ip6erspan_rcv(struct sk_buff *skb,
ERSPAN_V2_MDSIZE);
__set_bit(IP_TUNNEL_ERSPAN_OPT_BIT,
info->key.tun_flags);
- info->options_len = sizeof(*md);
ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
@@ -1366,9 +1368,16 @@ static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
{
struct ip6_tnl *t = netdev_priv(dev);
struct ipv6hdr *ipv6h;
+ int needed;
__be16 *p;
- ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
+ needed = t->hlen + sizeof(*ipv6h);
+ if (skb_headroom(skb) < needed &&
+ pskb_expand_head(skb, HH_DATA_ALIGN(needed - skb_headroom(skb)),
+ 0, GFP_ATOMIC))
+ return -needed;
+
+ ipv6h = skb_push(skb, needed);
ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
t->fl.u.ip6.flowlabel,
true, &t->fl.u.ip6));
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index aee6a10b112a..a3e051dc66ee 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1470,7 +1470,18 @@ static struct rt6_info *rt6_make_pcpu_route(struct net *net,
p = this_cpu_ptr(res->nh->rt6i_pcpu);
prev = cmpxchg(p, NULL, pcpu_rt);
- BUG_ON(prev);
+ if (unlikely(prev)) {
+ /*
+ * Another task on this CPU already installed a pcpu_rt.
+ * This can happen on PREEMPT_RT where preemption is possible.
+ * Free our allocation and return the existing one.
+ */
+ WARN_ON_ONCE(!IS_ENABLED(CONFIG_PREEMPT_RT));
+
+ dst_dev_put(&pcpu_rt->dst);
+ dst_release(&pcpu_rt->dst);
+ return prev;
+ }
if (res->f6i->fib6_destroying) {
struct fib6_info *from;