From d9e44981739a96f1a468c13bbbd54ace378caf1c Mon Sep 17 00:00:00 2001 From: Taehee Yoo Date: Mon, 28 Dec 2020 15:21:36 +0000 Subject: bareudp: set NETIF_F_LLTX flag Like other tunneling interfaces, the bareudp doesn't need TXLOCK. So, It is good to set the NETIF_F_LLTX flag to improve performance and to avoid lockdep's false-positive warning. Test commands: ip netns add A ip netns add B ip link add veth0 netns A type veth peer name veth1 netns B ip netns exec A ip link set veth0 up ip netns exec A ip a a 10.0.0.1/24 dev veth0 ip netns exec B ip link set veth1 up ip netns exec B ip a a 10.0.0.2/24 dev veth1 for i in {2..1} do let A=$i-1 ip netns exec A ip link add bareudp$i type bareudp \ dstport $i ethertype ip ip netns exec A ip link set bareudp$i up ip netns exec A ip a a 10.0.$i.1/24 dev bareudp$i ip netns exec A ip r a 10.0.$i.2 encap ip src 10.0.$A.1 \ dst 10.0.$A.2 via 10.0.$i.2 dev bareudp$i ip netns exec B ip link add bareudp$i type bareudp \ dstport $i ethertype ip ip netns exec B ip link set bareudp$i up ip netns exec B ip a a 10.0.$i.2/24 dev bareudp$i ip netns exec B ip r a 10.0.$i.1 encap ip src 10.0.$A.2 \ dst 10.0.$A.1 via 10.0.$i.1 dev bareudp$i done ip netns exec A ping 10.0.2.2 Splat looks like: [ 96.992803][ T822] ============================================ [ 96.993954][ T822] WARNING: possible recursive locking detected [ 96.995102][ T822] 5.10.0+ #819 Not tainted [ 96.995927][ T822] -------------------------------------------- [ 96.997091][ T822] ping/822 is trying to acquire lock: [ 96.998083][ T822] ffff88810f753898 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960 [ 96.999813][ T822] [ 96.999813][ T822] but task is already holding lock: [ 97.001192][ T822] ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960 [ 97.002908][ T822] [ 97.002908][ T822] other info that might help us debug this: [ 97.004401][ T822] Possible unsafe locking scenario: [ 97.004401][ T822] [ 97.005784][ T822] CPU0 [ 97.006407][ T822] ---- [ 97.007010][ T822] lock(_xmit_NONE#2); [ 97.007779][ T822] lock(_xmit_NONE#2); [ 97.008550][ T822] [ 97.008550][ T822] *** DEADLOCK *** [ 97.008550][ T822] [ 97.010057][ T822] May be due to missing lock nesting notation [ 97.010057][ T822] [ 97.011594][ T822] 7 locks held by ping/822: [ 97.012426][ T822] #0: ffff888109a144f0 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0x12f7/0x2b00 [ 97.014191][ T822] #1: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020 [ 97.016045][ T822] #2: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960 [ 97.017897][ T822] #3: ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960 [ 97.019684][ T822] #4: ffffffffbce2f600 (rcu_read_lock){....}-{1:2}, at: bareudp_xmit+0x31b/0x3690 [bareudp] [ 97.021573][ T822] #5: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020 [ 97.023424][ T822] #6: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960 [ 97.025259][ T822] [ 97.025259][ T822] stack backtrace: [ 97.026349][ T822] CPU: 3 PID: 822 Comm: ping Not tainted 5.10.0+ #819 [ 97.027609][ T822] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 97.029407][ T822] Call Trace: [ 97.030015][ T822] dump_stack+0x99/0xcb [ 97.030783][ T822] __lock_acquire.cold.77+0x149/0x3a9 [ 97.031773][ T822] ? stack_trace_save+0x81/0xa0 [ 97.032661][ T822] ? register_lock_class+0x1910/0x1910 [ 97.033673][ T822] ? register_lock_class+0x1910/0x1910 [ 97.034679][ T822] ? rcu_read_lock_sched_held+0x91/0xc0 [ 97.035697][ T822] ? rcu_read_lock_bh_held+0xa0/0xa0 [ 97.036690][ T822] lock_acquire+0x1b2/0x730 [ 97.037515][ T822] ? __dev_queue_xmit+0x1f52/0x2960 [ 97.038466][ T822] ? check_flags+0x50/0x50 [ 97.039277][ T822] ? netif_skb_features+0x296/0x9c0 [ 97.040226][ T822] ? validate_xmit_skb+0x29/0xb10 [ 97.041151][ T822] _raw_spin_lock+0x30/0x70 [ 97.041977][ T822] ? __dev_queue_xmit+0x1f52/0x2960 [ 97.042927][ T822] __dev_queue_xmit+0x1f52/0x2960 [ 97.043852][ T822] ? netdev_core_pick_tx+0x290/0x290 [ 97.044824][ T822] ? mark_held_locks+0xb7/0x120 [ 97.045712][ T822] ? lockdep_hardirqs_on_prepare+0x12c/0x3e0 [ 97.046824][ T822] ? __local_bh_enable_ip+0xa5/0xf0 [ 97.047771][ T822] ? ___neigh_create+0x12a8/0x1eb0 [ 97.048710][ T822] ? trace_hardirqs_on+0x41/0x120 [ 97.049626][ T822] ? ___neigh_create+0x12a8/0x1eb0 [ 97.050556][ T822] ? __local_bh_enable_ip+0xa5/0xf0 [ 97.051509][ T822] ? ___neigh_create+0x12a8/0x1eb0 [ 97.052443][ T822] ? check_chain_key+0x244/0x5f0 [ 97.053352][ T822] ? rcu_read_lock_bh_held+0x56/0xa0 [ 97.054317][ T822] ? ip_finish_output2+0x6ea/0x2020 [ 97.055263][ T822] ? pneigh_lookup+0x410/0x410 [ 97.056135][ T822] ip_finish_output2+0x6ea/0x2020 [ ... ] Acked-by: Guillaume Nault Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.") Signed-off-by: Taehee Yoo Link: https://lore.kernel.org/r/20201228152136.24215-1-ap420073@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/bareudp.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/net/bareudp.c') diff --git a/drivers/net/bareudp.c b/drivers/net/bareudp.c index 85ebd2b7e446..aea10196c222 100644 --- a/drivers/net/bareudp.c +++ b/drivers/net/bareudp.c @@ -534,6 +534,7 @@ static void bareudp_setup(struct net_device *dev) SET_NETDEV_DEVTYPE(dev, &bareudp_type); dev->features |= NETIF_F_SG | NETIF_F_HW_CSUM; dev->features |= NETIF_F_RXCSUM; + dev->features |= NETIF_F_LLTX; dev->features |= NETIF_F_GSO_SOFTWARE; dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM; dev->hw_features |= NETIF_F_GSO_SOFTWARE; -- cgit v1.2.3 From 10ad3e998fa0c25315f27cf3002ff8b02dc31c38 Mon Sep 17 00:00:00 2001 From: Taehee Yoo Date: Mon, 28 Dec 2020 15:21:46 +0000 Subject: bareudp: Fix use of incorrect min_headroom size In the bareudp6_xmit_skb(), it calculates min_headroom. At that point, it uses struct iphdr, but it's not correct. So panic could occur. The struct ipv6hdr should be used. Test commands: ip netns add A ip netns add B ip link add veth0 netns A type veth peer name veth1 netns B ip netns exec A ip link set veth0 up ip netns exec A ip a a 2001:db8:0::1/64 dev veth0 ip netns exec B ip link set veth1 up ip netns exec B ip a a 2001:db8:0::2/64 dev veth1 for i in {10..1} do let A=$i-1 ip netns exec A ip link add bareudp$i type bareudp dstport $i \ ethertype 0x86dd ip netns exec A ip link set bareudp$i up ip netns exec A ip -6 a a 2001:db8:$i::1/64 dev bareudp$i ip netns exec A ip -6 r a 2001:db8:$i::2 encap ip6 src \ 2001:db8:$A::1 dst 2001:db8:$A::2 via 2001:db8:$i::2 \ dev bareudp$i ip netns exec B ip link add bareudp$i type bareudp dstport $i \ ethertype 0x86dd ip netns exec B ip link set bareudp$i up ip netns exec B ip -6 a a 2001:db8:$i::2/64 dev bareudp$i ip netns exec B ip -6 r a 2001:db8:$i::1 encap ip6 src \ 2001:db8:$A::2 dst 2001:db8:$A::1 via 2001:db8:$i::1 \ dev bareudp$i done ip netns exec A ping 2001:db8:7::2 Splat looks like: [ 66.436679][ C2] skbuff: skb_under_panic: text:ffffffff928614c8 len:454 put:14 head:ffff88810abb4000 data:ffff88810abb3ffa tail:0x1c0 end:0x3ec0 dev:veth0 [ 66.441626][ C2] ------------[ cut here ]------------ [ 66.443458][ C2] kernel BUG at net/core/skbuff.c:109! [ 66.445313][ C2] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 66.447606][ C2] CPU: 2 PID: 913 Comm: ping Not tainted 5.10.0+ #819 [ 66.450251][ C2] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 66.453713][ C2] RIP: 0010:skb_panic+0x15d/0x15f [ 66.455345][ C2] Code: 98 fe 4c 8b 4c 24 10 53 8b 4d 70 45 89 e0 48 c7 c7 60 8b 78 93 41 57 41 56 41 55 48 8b 54 24 20 48 8b 74 24 28 e8 b5 40 f9 ff <0f> 0b 48 8b 6c 24 20 89 34 24 e8 08 c9 98 fe 8b 34 24 48 c7 c1 80 [ 66.462314][ C2] RSP: 0018:ffff888119209648 EFLAGS: 00010286 [ 66.464281][ C2] RAX: 0000000000000089 RBX: ffff888003159000 RCX: 0000000000000000 [ 66.467216][ C2] RDX: 0000000000000089 RSI: 0000000000000008 RDI: ffffed10232412c0 [ 66.469768][ C2] RBP: ffff88810a53d440 R08: ffffed102328018d R09: ffffed102328018d [ 66.472297][ C2] R10: ffff888119400c67 R11: ffffed102328018c R12: 000000000000000e [ 66.474833][ C2] R13: ffff88810abb3ffa R14: 00000000000001c0 R15: 0000000000003ec0 [ 66.477361][ C2] FS: 00007f37c0c72f00(0000) GS:ffff888119200000(0000) knlGS:0000000000000000 [ 66.480214][ C2] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 66.482296][ C2] CR2: 000055a058808570 CR3: 000000011039e002 CR4: 00000000003706e0 [ 66.484811][ C2] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 66.487793][ C2] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 66.490424][ C2] Call Trace: [ 66.491469][ C2] [ 66.492374][ C2] ? eth_header+0x28/0x190 [ 66.494054][ C2] ? eth_header+0x28/0x190 [ 66.495401][ C2] skb_push.cold.99+0x22/0x22 [ 66.496700][ C2] eth_header+0x28/0x190 [ 66.497867][ C2] neigh_resolve_output+0x3de/0x720 [ 66.499615][ C2] ? __neigh_update+0x7e8/0x20a0 [ 66.501176][ C2] __neigh_update+0x8bd/0x20a0 [ 66.502749][ C2] ndisc_update+0x34/0xc0 [ 66.504010][ C2] ndisc_recv_na+0x8da/0xb80 [ 66.505041][ C2] ? pndisc_redo+0x20/0x20 [ 66.505888][ C2] ? rcu_read_lock_sched_held+0xc0/0xc0 [ 66.506965][ C2] ndisc_rcv+0x3a0/0x470 [ 66.507797][ C2] icmpv6_rcv+0xad9/0x1b00 [ 66.508645][ C2] ip6_protocol_deliver_rcu+0xcd6/0x1560 [ 66.509719][ C2] ip6_input_finish+0x5b/0xf0 [ 66.510615][ C2] ip6_input+0xcd/0x2d0 [ 66.511406][ C2] ? ip6_input_finish+0xf0/0xf0 [ 66.512327][ C2] ? rcu_read_lock_held+0x91/0xa0 [ 66.513279][ C2] ? ip6_protocol_deliver_rcu+0x1560/0x1560 [ 66.514414][ C2] ipv6_rcv+0xe8/0x300 [ ... ] Acked-by: Guillaume Nault Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.") Signed-off-by: Taehee Yoo Link: https://lore.kernel.org/r/20201228152146.24270-1-ap420073@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/bareudp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/bareudp.c') diff --git a/drivers/net/bareudp.c b/drivers/net/bareudp.c index aea10196c222..708171c0d628 100644 --- a/drivers/net/bareudp.c +++ b/drivers/net/bareudp.c @@ -380,7 +380,7 @@ static int bareudp6_xmit_skb(struct sk_buff *skb, struct net_device *dev, goto free_dst; min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len + - BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr); + BAREUDP_BASE_HLEN + info->options_len + sizeof(struct ipv6hdr); err = skb_cow_head(skb, min_headroom); if (unlikely(err)) -- cgit v1.2.3