From: Pablo Neira Ayuso pablo@netfilter.org
[ Upstream commit 34a4c95abd25ab41fb390b985a08a651b1fa0b0f ]
BH must be disabled when invoking nf_conncount_gc_list() to perform garbage collection, otherwise deadlock might happen.
nf_conncount_add+0x1f/0x50 [nf_conncount] nft_connlimit_eval+0x4c/0xe0 [nft_connlimit] nft_dynset_eval+0xb5/0x100 [nf_tables] nft_do_chain+0xea/0x420 [nf_tables] ? sch_direct_xmit+0x111/0x360 ? noqueue_init+0x10/0x10 ? __qdisc_run+0x84/0x510 ? tcp_packet+0x655/0x1610 [nf_conntrack] ? ip_finish_output2+0x1a7/0x430 ? tcp_error+0x130/0x150 [nf_conntrack] ? nf_conntrack_in+0x1fc/0x4c0 [nf_conntrack] nft_do_chain_ipv4+0x66/0x80 [nf_tables] nf_hook_slow+0x44/0xc0 ip_rcv+0xb5/0xd0 ? ip_rcv_finish_core.isra.19+0x360/0x360 __netif_receive_skb_one_core+0x52/0x70 netif_receive_skb_internal+0x34/0xe0 napi_gro_receive+0xba/0xe0 e1000_clean_rx_irq+0x1e9/0x420 [e1000e] e1000e_poll+0xbe/0x290 [e1000e] net_rx_action+0x149/0x3b0 __do_softirq+0xde/0x2d8 irq_exit+0xba/0xc0 do_IRQ+0x85/0xd0 common_interrupt+0xf/0xf </IRQ> RIP: 0010:nf_conncount_gc_list+0x3b/0x130 [nf_conncount]
Fixes: 2f971a8f4255 ("netfilter: nf_conncount: move all list iterations under spinlock") Reported-by: Laura Garcia Liebana nevola@gmail.com Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/nft_connlimit.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nft_connlimit.c b/net/netfilter/nft_connlimit.c index af1497ab94642..69d6173f91e2b 100644 --- a/net/netfilter/nft_connlimit.c +++ b/net/netfilter/nft_connlimit.c @@ -218,8 +218,13 @@ static void nft_connlimit_destroy_clone(const struct nft_ctx *ctx, static bool nft_connlimit_gc(struct net *net, const struct nft_expr *expr) { struct nft_connlimit *priv = nft_expr_priv(expr); + bool ret;
- return nf_conncount_gc_list(net, &priv->list); + local_bh_disable(); + ret = nf_conncount_gc_list(net, &priv->list); + local_bh_enable(); + + return ret; }
static struct nft_expr_type nft_connlimit_type;