syzbot

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097]
CPU: 1 PID: 9586 Comm: kworker/u8:28 Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Workqueue: netns cleanup_net
RIP: 0010:__fib6_drop_pcpu_from+0x1fd/0x3d0 net/ipv6/ip6_fib.c:987
Code: 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 ef e8 3a 42 cc 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 14 42 cc f7 48 8b 45 00 4c 39 f0
RSP: 0018:ffffc90004c86a60 EFLAGS: 00010216
RAX: 0000000000000012 RBX: ffffffff8ddbc9e0 RCX: ffff88805330bc00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000093 R08: ffffffff8a2fa8d8 R09: 1ffffffff25f56b0
R10: dffffc0000000000 R11: fffffbfff25f56b1 R12: dffffc0000000000
R13: ffff88805bd77110 R14: ffff88805bd77000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc8a91ded58 CR3: 000000007daa6000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 fib6_drop_pcpu_from net/ipv6/ip6_fib.c:1031 [inline]
 fib6_purge_rt+0x193/0x890 net/ipv6/ip6_fib.c:1042
 fib6_del_route net/ipv6/ip6_fib.c:2002 [inline]
 fib6_del+0xe77/0x1600 net/ipv6/ip6_fib.c:2047
 fib6_clean_node+0x2f7/0x5e0 net/ipv6/ip6_fib.c:2209
 fib6_walk_continue+0x65a/0x8f0 net/ipv6/ip6_fib.c:2131
 fib6_walk+0x168/0x2b0 net/ipv6/ip6_fib.c:2179
 fib6_clean_tree net/ipv6/ip6_fib.c:2259 [inline]
 __fib6_clean_all+0x31f/0x4b0 net/ipv6/ip6_fib.c:2275
 rt6_sync_down_dev net/ipv6/route.c:4908 [inline]
 rt6_disable_ip+0x170/0x880 net/ipv6/route.c:4913
 addrconf_ifdown+0x15d/0x1bc0 net/ipv6/addrconf.c:3855
 addrconf_notify+0x3cb/0x1020
 notifier_call_chain+0x1a1/0x3e0 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2030 [inline]
 call_netdevice_notifiers net/core/dev.c:2044 [inline]
 dev_close_many+0x33c/0x4c0 net/core/dev.c:1585
 unregister_netdevice_many_notify+0x544/0x16b0 net/core/dev.c:11194
 unregister_netdevice_many net/core/dev.c:11277 [inline]
 unregister_netdevice_queue+0x303/0x370 net/core/dev.c:11156
 unregister_netdevice include/linux/netdevice.h:3119 [inline]
 nsim_destroy+0x180/0x5c0 drivers/net/netdevsim/netdev.c:777
 __nsim_dev_port_del+0x14b/0x1b0 drivers/net/netdevsim/dev.c:1425
 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1437 [inline]
 nsim_dev_reload_destroy+0x28a/0x490 drivers/net/netdevsim/dev.c:1658
 nsim_dev_reload_down+0x98/0xd0 drivers/net/netdevsim/dev.c:965
 devlink_reload+0x18d/0x870 net/devlink/dev.c:461
 devlink_pernet_pre_exit+0x1f3/0x440 net/devlink/core.c:509
 ops_pre_exit_list net/core/net_namespace.c:163 [inline]
 cleanup_net+0x617/0xcc0 net/core/net_namespace.c:620
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__fib6_drop_pcpu_from+0x1fd/0x3d0 net/ipv6/ip6_fib.c:987
Code: 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 ef e8 3a 42 cc 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 14 42 cc f7 48 8b 45 00 4c 39 f0
RSP: 0018:ffffc90004c86a60 EFLAGS: 00010216
RAX: 0000000000000012 RBX: ffffffff8ddbc9e0 RCX: ffff88805330bc00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000093 R08: ffffffff8a2fa8d8 R09: 1ffffffff25f56b0
R10: dffffc0000000000 R11: fffffbfff25f56b1 R12: dffffc0000000000
R13: ffff88805bd77110 R14: ffff88805bd77000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc8a91ded58 CR3: 000000007daa6000 CR4: 0000000000350ef0
----------------
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 3a 42 cc f7       	call   0xf7cc424d
  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 14 42 cc f7       	call   0xf7cc424d
  39:	48 8b 45 00          	mov    0x0(%rbp),%rax
  3d:	4c 39 f0             	cmp    %r14,%rax