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| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2014-01-13 05:45:22 +0400 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-02-15 23:20:10 +0400 |
| commit | 609365b9ea77703c6be6e3cae5d5f31fa54fef90 (patch) | |
| tree | 8cb0523c192e2bb60441fb7106d2e1b0d3a8df37 /net/ipv6 | |
| parent | 96a042c27e22876b68e64c648cb79226b38d3b70 (diff) | |
| download | linux-609365b9ea77703c6be6e3cae5d5f31fa54fef90.tar.xz | |
net: avoid reference counter overflows on fib_rules in multicast forwarding
[ Upstream commit 95f4a45de1a0f172b35451fc52283290adb21f6e ]
Bob Falken reported that after 4G packets, multicast forwarding stopped
working. This was because of a rule reference counter overflow which
freed the rule as soon as the overflow happend.
This patch solves this by adding the FIB_LOOKUP_NOREF flag to
fib_rules_lookup calls. This is safe even from non-rcu locked sections
as in this case the flag only implies not taking a reference to the rule,
which we don't need at all.
Rules only hold references to the namespace, which are guaranteed to be
available during the call of the non-rcu protected function reg_vif_xmit
because of the interface reference which itself holds a reference to
the net namespace.
Fixes: f0ad0860d01e47 ("ipv4: ipmr: support multiple tables")
Fixes: d1db275dd3f6e4 ("ipv6: ip6mr: support multiple tables")
Reported-by: Bob Falken <NetFestivalHaveFun@gmx.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/ip6mr.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index f5af259386e0..f96c96f6e4fd 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -139,9 +139,12 @@ static struct mr6_table *ip6mr_get_table(struct net *net, u32 id) static int ip6mr_fib_lookup(struct net *net, struct flowi6 *flp6, struct mr6_table **mrt) { - struct ip6mr_result res; - struct fib_lookup_arg arg = { .result = &res, }; int err; + struct ip6mr_result res; + struct fib_lookup_arg arg = { + .result = &res, + .flags = FIB_LOOKUP_NOREF, + }; err = fib_rules_lookup(net->ipv6.mr6_rules_ops, flowi6_to_flowi(flp6), 0, &arg); |