syzbot

veth0_macvtap: left promiscuous mode
veth1_vlan: left promiscuous mode
veth0_vlan: left promiscuous mode
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097]
CPU: 1 UID: 0 PID: 7210 Comm: kworker/u8:10 Not tainted 6.15.0-rc3-syzkaller-00019-gbc3372351d0c #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: netns cleanup_net
RIP: 0010:__fib6_drop_pcpu_from+0x1fd/0x3d0 net/ipv6/ip6_fib.c:980
Code: 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 ef e8 8a 38 67 f7 48 8b 6d 00 48 85 ed 74 30 48 81 c5 90 00 00 00 48 89 e8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 ef e8 64 38 67 f7 48 8b 45 00 4c 39 f0
RSP: 0018:ffffc90003f26c00 EFLAGS: 00010206
RAX: 0000000000000012 RBX: ffffffff8e786c10 RCX: ffff888031653c00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000093 R08: ffffffff8ac32c58 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888022f60110 R14: ffff888022f60000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881250cf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff5835eff8 CR3: 000000006e3da000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 fib6_drop_pcpu_from net/ipv6/ip6_fib.c:1024 [inline]
 fib6_purge_rt+0x195/0x890 net/ipv6/ip6_fib.c:1035
 fib6_del_route net/ipv6/ip6_fib.c:1995 [inline]
 fib6_del+0xe73/0x1600 net/ipv6/ip6_fib.c:2040
 fib6_clean_node+0x2f9/0x5f0 net/ipv6/ip6_fib.c:2202
 fib6_walk_continue+0x658/0x8f0 net/ipv6/ip6_fib.c:2124
 fib6_walk+0x168/0x2b0 net/ipv6/ip6_fib.c:2172
 fib6_clean_tree net/ipv6/ip6_fib.c:2252 [inline]
 __fib6_clean_all+0x321/0x4b0 net/ipv6/ip6_fib.c:2268
 rt6_sync_down_dev net/ipv6/route.c:4951 [inline]
 rt6_disable_ip+0x172/0x810 net/ipv6/route.c:4956
 addrconf_ifdown+0x15f/0x1b10 net/ipv6/addrconf.c:3854
 addrconf_notify+0x3cb/0x1020 net/ipv6/addrconf.c:-1
 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline]
 call_netdevice_notifiers net/core/dev.c:2228 [inline]
 dev_close_many+0x33e/0x4c0 net/core/dev.c:1731
 unregister_netdevice_many_notify+0x87f/0x2640 net/core/dev.c:11952
 unregister_netdevice_many net/core/dev.c:12046 [inline]
 default_device_exit_batch+0x7ff/0x880 net/core/dev.c:12538
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x8af/0xd60 net/core/net_namespace.c:654
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd50 kernel/workqueue.c:3400
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__fib6_drop_pcpu_from+0x1fd/0x3d0 net/ipv6/ip6_fib.c:980
Code: 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 ef e8 8a 38 67 f7 48 8b 6d 00 48 85 ed 74 30 48 81 c5 90 00 00 00 48 89 e8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 ef e8 64 38 67 f7 48 8b 45 00 4c 39 f0
RSP: 0018:ffffc90003f26c00 EFLAGS: 00010206
RAX: 0000000000000012 RBX: ffffffff8e786c10 RCX: ffff888031653c00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000093 R08: ffffffff8ac32c58 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888022f60110 R14: ffff888022f60000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881250cf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff5835eff8 CR3: 000000000eb38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	48 c1 e8 03          	shr    $0x3,%rax
   4:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)
   9:	74 08                	je     0x13
   b:	48 89 ef             	mov    %rbp,%rdi
   e:	e8 8a 38 67 f7       	call   0xf767389d
  13:	48 8b 6d 00          	mov    0x0(%rbp),%rbp
  17:	48 85 ed             	test   %rbp,%rbp
  1a:	74 30                	je     0x4c
  1c:	48 81 c5 90 00 00 00 	add    $0x90,%rbp
  23:	48 89 e8             	mov    %rbp,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 ef             	mov    %rbp,%rdi
  34:	e8 64 38 67 f7       	call   0xf767389d
  39:	48 8b 45 00          	mov    0x0(%rbp),%rax
  3d:	4c 39 f0             	cmp    %r14,%rax