From 9ff566074689e3aed1488780b97714ec43ba361d Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Sun, 17 Feb 2008 18:39:54 -0800 Subject: [PATCH] Revert "[NDISC]: Fix race in generic address resolution" This reverts commit 69cc64d8d92bf852f933e90c888dfff083bd4fc9. It causes recursive locking in IPV6 because unlike other neighbour layer clients, it even needs neighbour cache entries to send neighbour soliciation messages :-( We'll have to find another way to fix this race. Signed-off-by: David S. Miller --- net/core/neighbour.c | 12 +++++++++--- net/ipv4/arp.c | 3 +++ 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 7bb6a9a1256..a16cf1ec5e5 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -834,12 +834,18 @@ static void neigh_timer_handler(unsigned long arg) } if (neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) { struct sk_buff *skb = skb_peek(&neigh->arp_queue); - + /* keep skb alive even if arp_queue overflows */ + if (skb) + skb_get(skb); + write_unlock(&neigh->lock); neigh->ops->solicit(neigh, skb); atomic_inc(&neigh->probes); - } + if (skb) + kfree_skb(skb); + } else { out: - write_unlock(&neigh->lock); + write_unlock(&neigh->lock); + } if (notify) neigh_update_notify(neigh); diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index c663fa5339e..8e17f65f400 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -368,6 +368,7 @@ static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) if (!(neigh->nud_state&NUD_VALID)) printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n"); dst_ha = neigh->ha; + read_lock_bh(&neigh->lock); } else if ((probes -= neigh->parms->app_probes) < 0) { #ifdef CONFIG_ARPD neigh_app_ns(neigh); @@ -377,6 +378,8 @@ static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, dst_ha, dev->dev_addr, NULL); + if (dst_ha) + read_unlock_bh(&neigh->lock); } static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip) -- 2.39.3