On Fri, Feb 07, 2025 at 03:56:57PM +0100, vgiraud.opensource@witekio.com wrote:
From: Dong Chenchen dongchenchen2@huawei.com
[ Upstream commit c44daa7e3c73229f7ac74985acb8c7fb909c4e0a ]
arp link failure may trigger ip_rt_bug while xfrm enabled, call trace is:
WARNING: CPU: 0 PID: 0 at net/ipv4/route.c:1241 ip_rt_bug+0x14/0x20 Modules linked in: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.0-rc6-00077-g2e1b3cc9d7f7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:ip_rt_bug+0x14/0x20 Call Trace:
<IRQ> ip_send_skb+0x14/0x40 __icmp_send+0x42d/0x6a0 ipv4_link_failure+0xe2/0x1d0 arp_error_report+0x3c/0x50 neigh_invalidate+0x8d/0x100 neigh_timer_handler+0x2e1/0x330 call_timer_fn+0x21/0x120 __run_timer_base.part.0+0x1c9/0x270 run_timer_softirq+0x4c/0x80 handle_softirqs+0xac/0x280 irq_exit_rcu+0x62/0x80 sysvec_apic_timer_interrupt+0x77/0x90
The script below reproduces this scenario: ip xfrm policy add src 0.0.0.0/0 dst 0.0.0.0/0 \ dir out priority 0 ptype main flag localok icmp ip l a veth1 type veth ip a a 192.168.141.111/24 dev veth0 ip l s veth0 up ping 192.168.141.155 -c 1
icmp_route_lookup() create input routes for locally generated packets while xfrm relookup ICMP traffic.Then it will set input route (dst->out = ip_rt_bug) to skb for DESTUNREACH.
For ICMP err triggered by locally generated packets, dst->dev of output route is loopback. Generally, xfrm relookup verification is not required on loopback interfaces (net.ipv4.conf.lo.disable_xfrm = 1).
Skip icmp relookup for locally generated packets to fix it.
Fixes: 8b7817f3a959 ("[IPSEC]: Add ICMP host relookup support") Signed-off-by: Dong Chenchen dongchenchen2@huawei.com Reviewed-by: David Ahern dsahern@kernel.org Reviewed-by: Eric Dumazet edumazet@google.com Link: https://patch.msgid.link/20241127040850.1513135-1-dongchenchen2@huawei.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Bruno VERNAY bruno.vernay@se.com Signed-off-by: Victor Giraud vgiraud.opensource@witekio.com
net/ipv4/icmp.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 9dffdd876fef..ab830c093f7e 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -522,6 +522,9 @@ static struct rtable *icmp_route_lookup(struct net *net, if (rt != rt2) return rt; } else if (PTR_ERR(rt) == -EPERM) {
if (inet_addr_type_dev_table(net, route_lookup_dev,fl4->daddr) == RTN_LOCAL)return rt;
Are you sure this backport is correct? Have you tested it? It looks different from the original so you need to document why it is different somewhere.
I'm dropping both of these backports, please fix up and resend.
thanks,
greg k-h