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authorEric Dumazet <edumazet@google.com>2017-03-17 08:05:28 -0700
committerDavid S. Miller <davem@davemloft.net>2017-03-21 17:21:27 -0700
commitaea92fb2e09e29653b023d4254ac9fbf94221538 (patch)
tree146bf8ca4cb9b88ca710c379a317e7135db667f2
parent09050957fae896e001498af1aa35c446a11cb47d (diff)
sch_dsmark: fix invalid skb_cow() usage
skb_cow(skb, sizeof(ip header)) is not very helpful in this context. First we need to use pskb_may_pull() to make sure the ip header is in skb linear part, then use skb_try_make_writable() to address clones issues. Fixes: 4c30719f4f55 ("[PKT_SCHED] dsmark: handle cloned and non-linear skb's") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/sched/sch_dsmark.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/net/sched/sch_dsmark.c b/net/sched/sch_dsmark.c
index 802ac7c2e5e8..5334e309f17f 100644
--- a/net/sched/sch_dsmark.c
+++ b/net/sched/sch_dsmark.c
@@ -201,9 +201,13 @@ static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch,
pr_debug("%s(skb %p,sch %p,[qdisc %p])\n", __func__, skb, sch, p);
if (p->set_tc_index) {
+ int wlen = skb_network_offset(skb);
+
switch (tc_skb_protocol(skb)) {
case htons(ETH_P_IP):
- if (skb_cow_head(skb, sizeof(struct iphdr)))
+ wlen += sizeof(struct iphdr);
+ if (!pskb_may_pull(skb, wlen) ||
+ skb_try_make_writable(skb, wlen))
goto drop;
skb->tc_index = ipv4_get_dsfield(ip_hdr(skb))
@@ -211,7 +215,9 @@ static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch,
break;
case htons(ETH_P_IPV6):
- if (skb_cow_head(skb, sizeof(struct ipv6hdr)))
+ wlen += sizeof(struct ipv6hdr);
+ if (!pskb_may_pull(skb, wlen) ||
+ skb_try_make_writable(skb, wlen))
goto drop;
skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb))