From 0bdc924bfb319fb10d1113cbf091fc26fb7b1f99 Mon Sep 17 00:00:00 2001 From: Faicker Mo Date: Fri, 23 May 2025 03:41:43 +0000 Subject: [PATCH] net: openvswitch: Fix the dead loop of MPLS parse The unexpected MPLS packet may not end with the bottom label stack. When there are many stacks, The label count value has wrapped around. A dead loop occurs, soft lockup/CPU stuck finally. stack backtrace: UBSAN: array-index-out-of-bounds in /build/linux-0Pa0xK/linux-5.15.0/net/openvswitch/flow.c:662:26 index -1 is out of range for type '__be32 [3]' CPU: 34 PID: 0 Comm: swapper/34 Kdump: loaded Tainted: G OE 5.15.0-121-generic #131-Ubuntu Hardware name: Dell Inc. PowerEdge C6420/0JP9TF, BIOS 2.12.2 07/14/2021 Call Trace: show_stack+0x52/0x5c dump_stack_lvl+0x4a/0x63 dump_stack+0x10/0x16 ubsan_epilogue+0x9/0x36 __ubsan_handle_out_of_bounds.cold+0x44/0x49 key_extract_l3l4+0x82a/0x840 [openvswitch] ? kfree_skbmem+0x52/0xa0 key_extract+0x9c/0x2b0 [openvswitch] ovs_flow_key_extract+0x124/0x350 [openvswitch] ovs_vport_receive+0x61/0xd0 [openvswitch] ? kernel_init_free_pages.part.0+0x4a/0x70 ? get_page_from_freelist+0x353/0x540 netdev_port_receive+0xc4/0x180 [openvswitch] ? netdev_port_receive+0x180/0x180 [openvswitch] netdev_frame_hook+0x1f/0x40 [openvswitch] __netif_receive_skb_core.constprop.0+0x23a/0xf00 __netif_receive_skb_list_core+0xfa/0x240 netif_receive_skb_list_internal+0x18e/0x2a0 napi_complete_done+0x7a/0x1c0 bnxt_poll+0x155/0x1c0 [bnxt_en] __napi_poll+0x30/0x180 net_rx_action+0x126/0x280 ? bnxt_msix+0x67/0x80 [bnxt_en] handle_softirqs+0xda/0x2d0 irq_exit_rcu+0x96/0xc0 common_interrupt+0x8e/0xa0 Fixes: fbdcdd78da7c ("Change in Openvswitch to support MPLS label depth of 3 in ingress direction") Signed-off-by: Faicker Mo Acked-by: Ilya Maximets Reviewed-by: Aaron Conole Link: https://patch.msgid.link/259D3404-575D-4A6D-B263-1DF59A67CF89@zenlayer.com Signed-off-by: Paolo Abeni --- net/openvswitch/flow.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c index 8a848ce72e29..b80bd3a90773 100644 --- a/net/openvswitch/flow.c +++ b/net/openvswitch/flow.c @@ -788,7 +788,7 @@ static int key_extract_l3l4(struct sk_buff *skb, struct sw_flow_key *key) memset(&key->ipv4, 0, sizeof(key->ipv4)); } } else if (eth_p_mpls(key->eth.type)) { - u8 label_count = 1; + size_t label_count = 1; memset(&key->mpls, 0, sizeof(key->mpls)); skb_set_inner_network_header(skb, skb->mac_len); -- 2.20.1