From: Eric Dumazet edumazet@google.com
[ Upstream commit aea92fb2e09e29653b023d4254ac9fbf94221538 ]
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 Signed-off-by: Sasha Levin alexander.levin@verizon.com --- net/sched/sch_dsmark.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/net/sched/sch_dsmark.c b/net/sched/sch_dsmark.c index 1308bbf460f7..b56d57984439 100644 --- a/net/sched/sch_dsmark.c +++ b/net/sched/sch_dsmark.c @@ -200,9 +200,13 @@ 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)) @@ -210,7 +214,9 @@ 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))