4.4-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
commit 05c0b86b9696802fd0ce5676a92a63f1b455bdf3 upstream.
Make it similar to IPv4 ip_expire(), and release the lock before calling icmp functions.
Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net [bwh: Backported to 4.4: adjust context] Signed-off-by: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/reassembly.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-)
--- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -92,7 +92,9 @@ EXPORT_SYMBOL(ip6_frag_init); void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq) { struct net_device *dev = NULL; + struct sk_buff *head;
+ rcu_read_lock(); spin_lock(&fq->q.lock);
if (fq->q.flags & INET_FRAG_COMPLETE) @@ -100,28 +102,34 @@ void ip6_expire_frag_queue(struct net *n
inet_frag_kill(&fq->q);
- rcu_read_lock(); dev = dev_get_by_index_rcu(net, fq->iif); if (!dev) - goto out_rcu_unlock; + goto out;
IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
/* Don't send error if the first segment did not arrive. */ - if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !fq->q.fragments) - goto out_rcu_unlock; + head = fq->q.fragments; + if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !head) + goto out;
/* But use as source device on which LAST ARRIVED * segment was received. And do not use fq->dev * pointer directly, device might already disappeared. */ - fq->q.fragments->dev = dev; - icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0); -out_rcu_unlock: - rcu_read_unlock(); + head->dev = dev; + skb_get(head); + spin_unlock(&fq->q.lock); + + icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0); + kfree_skb(head); + goto out_rcu_unlock; + out: spin_unlock(&fq->q.lock); +out_rcu_unlock: + rcu_read_unlock(); inet_frag_put(&fq->q); } EXPORT_SYMBOL(ip6_expire_frag_queue);