syzbot

general protection fault, probably for non-canonical address 0xdffffc0000000013: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000098-0x000000000000009f]
CPU: 1 PID: 15837 Comm: syz-executor.1 Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__lock_acquire+0xd94/0x54f0 kernel/locking/lockdep.c:4702
Code: e7 0d 41 bf 01 00 00 00 0f 86 8e 00 00 00 89 05 32 b9 e7 0d e9 83 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 0c 30 00 00 49 81 3e c0 92 15 8f 0f 84 39 f3 ff
RSP: 0018:ffffc90001d375f8 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000013 RSI: 0000000000000000 RDI: 0000000000000098
RBP: ffff888018773780 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000098 R15: 0000000000000000
FS:  00007f421baa1700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001acd848 CR3: 000000005e2f0000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 lock_acquire kernel/locking/lockdep.c:5442 [inline]
 lock_acquire+0x1a8/0x720 kernel/locking/lockdep.c:5407
 __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
 _raw_write_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:319
 pppoe_flush_dev drivers/net/ppp/pppoe.c:279 [inline]
 pppoe_device_event+0x221/0x930 drivers/net/ppp/pppoe.c:346
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2063
 call_netdevice_notifiers_extack net/core/dev.c:2075 [inline]
 call_netdevice_notifiers net/core/dev.c:2089 [inline]
 __dev_close_many+0xee/0x2e0 net/core/dev.c:1609
 dev_close_many+0x22c/0x620 net/core/dev.c:1660
 unregister_netdevice_many+0x3fd/0x1750 net/core/dev.c:10856
 default_device_exit_batch+0x2fa/0x3c0 net/core/dev.c:11399
 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:190
 setup_net+0x508/0x850 net/core/net_namespace.c:365
 copy_net_ns+0x31e/0x760 net/core/net_namespace.c:483
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x445/0x8e0 kernel/fork.c:2955
 __do_sys_unshare kernel/fork.c:3023 [inline]
 __se_sys_unshare kernel/fork.c:3021 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3021
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x465b09
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f421baa1188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 000000000056c0b0 RCX: 0000000000465b09
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000060000000
RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0b0
R13: 00007ffd347f314f R14: 00007f421baa1300 R15: 0000000000022000
Modules linked in:
---[ end trace c0236f2999804137 ]---
RIP: 0010:__lock_acquire+0xd94/0x54f0 kernel/locking/lockdep.c:4702
Code: e7 0d 41 bf 01 00 00 00 0f 86 8e 00 00 00 89 05 32 b9 e7 0d e9 83 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 0c 30 00 00 49 81 3e c0 92 15 8f 0f 84 39 f3 ff
RSP: 0018:ffffc90001d375f8 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000013 RSI: 0000000000000000 RDI: 0000000000000098
RBP: ffff888018773780 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000098 R15: 0000000000000000
FS:  00007f421baa1700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001acd848 CR3: 000000005e2f0000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400