Packets sitting in nfqueue might hold a reference to: - templates that specify the conntrack zone, because a percpu area is used and module removal is possible. - conntrack timeout policies and helper, where object removal leave a stale reference. Since these objects can just go away, drop enqueued packets to avoid stale reference to them. If there is a need for finer grain removal, this logic can be revisited to make selective packet drop upon dependencies. Fixes: 7e0b2b57f01d ("netfilter: nft_ct: add ct timeout support") Signed-off-by: Pablo Neira Ayuso --- I don't remember what email reported this. Compile-tested only. net/netfilter/nft_ct.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c index 6f2ae7cad731..db1bf69f8775 100644 --- a/net/netfilter/nft_ct.c +++ b/net/netfilter/nft_ct.c @@ -23,6 +23,7 @@ #include #include #include +#include "nf_internals.h" struct nft_ct_helper_obj { struct nf_conntrack_helper *helper4; @@ -543,6 +544,7 @@ static void __nft_ct_set_destroy(const struct nft_ctx *ctx, struct nft_ct *priv) #endif #ifdef CONFIG_NF_CONNTRACK_ZONES case NFT_CT_ZONE: + nf_queue_nf_hook_drop(ctx->net); mutex_lock(&nft_ct_pcpu_mutex); if (--nft_ct_pcpu_template_refcnt == 0) nft_ct_tmpl_put_pcpu(); @@ -1016,6 +1018,7 @@ static void nft_ct_timeout_obj_destroy(const struct nft_ctx *ctx, struct nft_ct_timeout_obj *priv = nft_obj_data(obj); struct nf_ct_timeout *timeout = priv->timeout; + nf_queue_nf_hook_drop(ctx->net); nf_ct_untimeout(ctx->net, timeout); nf_ct_netns_put(ctx->net, ctx->family); kfree(priv->timeout); @@ -1148,6 +1151,7 @@ static void nft_ct_helper_obj_destroy(const struct nft_ctx *ctx, { struct nft_ct_helper_obj *priv = nft_obj_data(obj); + nf_queue_nf_hook_drop(ctx->net); if (priv->helper4) nf_conntrack_helper_put(priv->helper4); if (priv->helper6) -- 2.47.3