-stable review patch. If anyone has any objections, please let us know. ------------------ From: Patrick McHardy [NETFILTER]: conntrack: fix {nf,ip}_ct_iterate_cleanup endless loops Fix {nf,ip}_ct_iterate_cleanup unconfirmed list handling: - unconfirmed entries can not be killed manually, they are removed on confirmation or final destruction of the conntrack entry, which means we might iterate forever without making forward progress. This can happen in combination with the conntrack event cache, which holds a reference to the conntrack entry, which is only released when the packet makes it all the way through the stack or a different packet is handled. - taking references to an unconfirmed entry and using it outside the locked section doesn't work, the list entries are not refcounted and another CPU might already be waiting to destroy the entry What the code really wants to do is make sure the references of the hash table to the selected conntrack entries are released, so they will be destroyed once all references from skbs and the event cache are dropped. Since unconfirmed entries haven't even entered the hash yet, simply mark them as dying and skip confirmation based on that. Signed-off-by: Patrick McHardy Signed-off-by: Greg Kroah-Hartman --- include/linux/netfilter_ipv4/ip_conntrack_core.h | 2 +- include/net/netfilter/nf_conntrack_core.h | 2 +- net/ipv4/netfilter/ip_conntrack_core.c | 2 +- net/netfilter/nf_conntrack_core.c | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) --- a/include/linux/netfilter_ipv4/ip_conntrack_core.h +++ b/include/linux/netfilter_ipv4/ip_conntrack_core.h @@ -45,7 +45,7 @@ static inline int ip_conntrack_confirm(s int ret = NF_ACCEPT; if (ct) { - if (!is_confirmed(ct)) + if (!is_confirmed(ct) && !is_dying(ct)) ret = __ip_conntrack_confirm(pskb); ip_ct_deliver_cached_events(ct); } --- a/include/net/netfilter/nf_conntrack_core.h +++ b/include/net/netfilter/nf_conntrack_core.h @@ -64,7 +64,7 @@ static inline int nf_conntrack_confirm(s int ret = NF_ACCEPT; if (ct) { - if (!nf_ct_is_confirmed(ct)) + if (!nf_ct_is_confirmed(ct) && !nf_ct_is_dying(ct)) ret = __nf_conntrack_confirm(pskb); nf_ct_deliver_cached_events(ct); } --- a/net/ipv4/netfilter/ip_conntrack_core.c +++ b/net/ipv4/netfilter/ip_conntrack_core.c @@ -1242,7 +1242,7 @@ get_next_corpse(int (*iter)(struct ip_co list_for_each_entry(h, &unconfirmed, list) { ct = tuplehash_to_ctrack(h); if (iter(ct, data)) - goto found; + set_bit(IPS_DYING_BIT, &ct->status); } write_unlock_bh(&ip_conntrack_lock); return NULL; --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1052,7 +1052,7 @@ get_next_corpse(int (*iter)(struct nf_co list_for_each_entry(h, &unconfirmed, list) { ct = nf_ct_tuplehash_to_ctrack(h); if (iter(ct, data)) - goto found; + set_bit(IPS_DYING_BIT, &ct->status); } write_unlock_bh(&nf_conntrack_lock); return NULL; -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/