Subject: Re: [PATCH v3 net-next 00/15] ip6mr: No RTNL for RTNL_FAMILY_IP6MR rtnetlink.

From: Jakub Kicinski <[email-masked]>
Date: Tue, 7 Apr 2026 18:42:02 -0700

On Tue,  7 Apr 2026 21:19:33 +0000 Kuniyuki Iwashima wrote:
> This series is the IPv6 version of
> 
>   https://lore.kernel.org/netdev/[email-masked]/
> 
> and removes RTNL from ip6mr rtnetlink handlers.

CI says:

[  857.648411][   T63] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP KASAN
[  857.648639][   T63] KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
[  857.648765][   T63] CPU: 2 UID: 0 PID: 63 Comm: kworker/2:2 Not tainted 7.0.0-rc6-virtme #1 PREEMPT(full) 
[  857.648903][   T63] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  857.649006][   T63] Workqueue: mld mld_ifc_work
[  857.649090][   T63] RIP: 0010:mroute6_is_socket+0x4a/0x80
[  857.649172][   T63] Code: df 48 89 f9 48 c1 e9 03 80 3c 11 00 75 2f 48 8b 80 e8 10 00 00 48 ba 00 00 00 00 00 fc ff df 48 8d 78 30 48 89 f9 48 c1 e9 03 <80> 3c 11 00 75 1c 48 83 78 30 00 0f 95 c0 48 83 c4 08 c3 48 89 04
[  857.649439][   T63] RSP: 0018:ffa00000004478b0 EFLAGS: 00010216
[  857.649533][   T63] RAX: 0000000000000000 RBX: ff1100000e2ae200 RCX: 0000000000000006
[  857.649645][   T63] RDX: dffffc0000000000 RSI: ff1100000e2ae200 RDI: 0000000000000030
[  857.649755][   T63] RBP: ff110000077d0900 R08: ffffffffa63b8550 R09: 1fe2200002937e85
[  857.649863][   T63] R10: ff11000010736898 R11: ff11000008ab40b0 R12: 1ff4000000088f20
[  857.649974][   T63] R13: ff11000008ab4000 R14: ff11000008c78800 R15: ff11000010736880
[  857.650083][   T63] FS:  0000000000000000(0000) GS:ff110000c2de4000(0000) knlGS:0000000000000000
[  857.650213][   T63] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  857.650307][   T63] CR2: 00007f1dc25d2574 CR3: 000000001c74f002 CR4: 0000000000771ef0
[  857.650421][   T63] PKRU: 55555554
[  857.650480][   T63] Call Trace:
[  857.650536][   T63]  <TASK>
[  857.650575][   T63]  ip6_finish_output2+0xa7f/0x1310
[  857.650653][   T63]  ? ip6_xmit+0x2000/0x2000
[  857.650724][   T63]  ? find_held_lock+0x2b/0x80
[  857.650800][   T63]  ? __lock_release.isra.0+0x6b/0x1a0
[  857.650873][   T63]  ? ip6_mtu+0x174/0x410
[  857.650929][   T63]  ip6_finish_output+0x701/0xe80
[  857.651002][   T63]  ip6_output+0x23f/0x7f0
[  857.651056][   T63]  ? ip6_finish_output+0xe80/0xe80
[  857.651128][   T63]  ? __lock_release.isra.0+0x6b/0x1a0
[  857.651201][   T63]  ? xfrm_bundle_lookup.constprop.0+0xba0/0xba0
[  857.651296][   T63]  ? mark_held_locks+0x40/0x70
[  857.651369][   T63]  ? __local_bh_enable_ip+0xa5/0x140
[  857.651443][   T63]  ? __local_bh_enable_ip+0xa5/0x140
[  857.651516][   T63]  ? icmp6_dst_alloc+0x317/0x4d0
[  857.651589][   T63]  mld_sendpack+0x9d6/0xec0
[  857.651661][   T63]  ? nf_hook.constprop.0+0x340/0x340
[  857.651734][   T63]  ? mld_send_cr+0x50f/0x820
[  857.651808][   T63]  mld_ifc_work+0x36/0x190
[  857.651880][   T63]  ? process_one_work+0xdb4/0x1410
[  857.651954][   T63]  process_one_work+0xdf5/0x1410
[  857.652028][   T63]  ? pwq_dec_nr_in_flight+0x710/0x710
[  857.652100][   T63]  ? lock_acquire.part.0+0xbc/0x260
[  857.652172][   T63]  worker_thread+0x4f1/0xd60
[  857.652244][   T63]  ? rescuer_thread+0x1320/0x1320
[  857.652318][   T63]  ? __kthread_parkme+0xbd/0x210
[  857.652391][   T63]  ? rescuer_thread+0x1320/0x1320
[  857.652495][   T63]  kthread+0x364/0x460
[  857.652550][   T63]  ? trace_irq_enable.constprop.0+0x9b/0x180
[  857.652641][   T63]  ? kthread_affine_node+0x330/0x330
[  857.652714][   T63]  ret_from_fork+0x474/0x6b0
[  857.652787][   T63]  ? arch_exit_to_user_mode_prepare.isra.0+0x140/0x140
[  857.652877][   T63]  ? __switch_to+0x540/0xd10
[  857.652952][   T63]  ? kthread_affine_node+0x330/0x330
[  857.653025][   T63]  ret_from_fork_asm+0x11/0x20
[  857.653102][   T63]  </TASK>
[  857.653157][   T63] Modules linked in: ip6_gre ip_gre gre act_gact cls_matchall sch_ingress ipt_REJECT nf_reject_ipv4 nft_compat nf_tables
[  857.653387][   T63] ---[ end trace 0000000000000000 ]---
[  857.653511][   T63] RIP: 0010:mroute6_is_socket+0x4a/0x80
[  857.653630][   T63] Code: df 48 89 f9 48 c1 e9 03 80 3c 11 00 75 2f 48 8b 80 e8 10 00 00 48 ba 00 00 00 00 00 fc ff df 48 8d 78 30 48 89 f9 48 c1 e9 03 <80> 3c 11 00 75 1c 48 83 78 30 00 0f 95 c0 48 83 c4 08 c3 48 89 04
[  857.653928][   T63] RSP: 0018:ffa00000004478b0 EFLAGS: 00010216
[  857.654063][   T63] RAX: 0000000000000000 RBX: ff1100000e2ae200 RCX: 0000000000000006
[  857.654267][   T63] RDX: dffffc0000000000 RSI: ff1100000e2ae200 RDI: 0000000000000030
[  857.654422][   T63] RBP: ff110000077d0900 R08: ffffffffa63b8550 R09: 1fe2200002937e85
[  857.654579][   T63] R10: ff11000010736898 R11: ff11000008ab40b0 R12: 1ff4000000088f20
[  857.654728][   T63] R13: ff11000008ab4000 R14: ff11000008c78800 R15: ff11000010736880
[  857.654876][   T63] FS:  0000000000000000(0000) GS:ff110000c2de4000(0000) knlGS:0000000000000000
[  857.655046][   T63] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  857.655189][   T63] CR2: 00007f1dc25d2574 CR3: 000000001c74f002 CR4: 0000000000771ef0
[  857.655340][   T63] PKRU: 55555554
[  857.655470][   T63] Kernel panic - not syncing: Fatal exception
[  857.655657][   T63] Kernel Offset: 0x23000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[  857.655864][   T63] ---[ end Kernel panic - not syncing: Fatal exception ]---