ACK: [SRU][F:linux-bluefield][PATCH] net/sched: act_ct: fix ref leak when switching zones
Tim Gardner
tim.gardner at canonical.com
Fri Jun 17 13:06:31 UTC 2022
On 6/16/22 16:50, Bodong Wang wrote:
> From: Marcelo Ricardo Leitner <marcelo.leitner at gmail.com>
>
> BugLink: https://launchpad.net/bugs/1979009
>
> When switching zones or network namespaces without doing a ct clear in
> between, it is now leaking a reference to the old ct entry. That's
> because tcf_ct_skb_nfct_cached() returns false and
> tcf_ct_flow_table_lookup() may simply overwrite it.
>
> The fix is to, as the ct entry is not reusable, free it already at
> tcf_ct_skb_nfct_cached().
>
> Reported-by: Florian Westphal <fw at strlen.de>
> Fixes: 2f131de361f6 ("net/sched: act_ct: Fix flow table lookup after ct clear or switching zones")
> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner at gmail.com>
> Signed-off-by: David S. Miller <davem at davemloft.net>
> Signed-off-by: Paul Blakey <paulb at nvidia.com>
> (backported from commit bcb74e132a76ce0502bb33d5b65533a4ed72d159)
> [paul: use ct_put rather than conntrack_put]
> Signed-off-by: Bodong Wang <bodong at nvidia.com>
> ---
> net/sched/act_ct.c | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
> index ed310be..0f44608 100644
> --- a/net/sched/act_ct.c
> +++ b/net/sched/act_ct.c
> @@ -598,22 +598,25 @@ static bool tcf_ct_skb_nfct_cached(struct net *net, struct sk_buff *skb,
> if (!ct)
> return false;
> if (!net_eq(net, read_pnet(&ct->ct_net)))
> - return false;
> + goto drop_ct;
> if (nf_ct_zone(ct)->id != zone_id)
> - return false;
> + goto drop_ct;
>
> /* Force conntrack entry direction. */
> if (force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
> if (nf_ct_is_confirmed(ct))
> nf_ct_kill(ct);
>
> - nf_conntrack_put(&ct->ct_general);
> - nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
> -
> - return false;
> + goto drop_ct;
> }
>
> return true;
> +
> +drop_ct:
> + nf_ct_put(ct);
> + nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
> +
> + return false;
> }
>
> /* Trim the skb to the length specified by the IP/IPv6 header,
Acked-by: Tim Gardner <tim.gardner at canonical.com>
--
-----------
Tim Gardner
Canonical, Inc
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