diff options
| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2014-01-13 02:45:22 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-06 11:05:48 -0800 |
| commit | df647935d589103da0b8f8e3d4354646c006e85b (patch) | |
| tree | dedc4674726e9697411fddaad3c5eccbcbf4e126 /net/ipv4 | |
| parent | 237275e9210b828f11c7dc2feac0ca1b0ced8eee (diff) | |
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/ipmr.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index a0b7166badb..94cd1ef1e31 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -154,9 +154,12 @@ static struct mr_table *ipmr_get_table(struct net *net, u32 id) static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4, struct mr_table **mrt) { - struct ipmr_result res; - struct fib_lookup_arg arg = { .result = &res, }; int err; + struct ipmr_result res; + struct fib_lookup_arg arg = { + .result = &res, + .flags = FIB_LOOKUP_NOREF, + }; err = fib_rules_lookup(net->ipv4.mr_rules_ops, flowi4_to_flowi(flp4), 0, &arg); |