syzbot

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 8971 Comm: syz.1.850 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:lec_arp_clear_vccs+0xad/0x380 net/atm/lec.c:1263
Code: e8 03 80 3c 28 00 74 08 4c 89 e7 e8 bd 38 9b f7 4c 89 74 24 18 49 8b 2c 24 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ef e8 95 38 9b f7 4d 8b 75 00 4d 8d a7 30
RSP: 0018:ffffc90015007728 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff8880588ab000 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffffff8bc08340 RDI: ffff8880588ab000
RBP: ffff88802dfa0000 R08: ffffffff8e6a8373 R09: 1ffffffff1cd506e
R10: dffffc0000000000 R11: fffffbfff1cd506f R12: ffff8880313b4650
R13: 0000000000000000 R14: ffff8880588ab030 R15: ffff8880313b4000
FS:  0000000000000000(0000) GS:ffff888125e35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f823ffc CR3: 0000000060a62000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 lec_vcc_close net/atm/lec.c:2183 [inline]
 lec_push+0x3cb/0x19f0 net/atm/lec.c:594
 vcc_destroy_socket net/atm/common.c:183 [inline]
 vcc_release+0x15f/0x580 net/atm/common.c:205
 svc_release+0x6c/0xe0 net/atm/svc.c:95
 __sock_release net/socket.c:662 [inline]
 sock_close+0xc3/0x240 net/socket.c:1455
 __fput+0x44c/0xa70 fs/file_table.c:468
 task_work_run+0x1d4/0x260 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x6c5/0x2310 kernel/exit.c:971
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
 get_signal+0x1285/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 ret_from_fork+0x616/0xb30 arch/x86/kernel/process.c:167
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:lec_arp_clear_vccs+0xad/0x380 net/atm/lec.c:1263
Code: e8 03 80 3c 28 00 74 08 4c 89 e7 e8 bd 38 9b f7 4c 89 74 24 18 49 8b 2c 24 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ef e8 95 38 9b f7 4d 8b 75 00 4d 8d a7 30
RSP: 0018:ffffc90015007728 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff8880588ab000 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffffff8bc08340 RDI: ffff8880588ab000
RBP: ffff88802dfa0000 R08: ffffffff8e6a8373 R09: 1ffffffff1cd506e
R10: dffffc0000000000 R11: fffffbfff1cd506f R12: ffff8880313b4650
R13: 0000000000000000 R14: ffff8880588ab030 R15: ffff8880313b4000
FS:  0000000000000000(0000) GS:ffff888125e35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f823ffc CR3: 0000000060a62000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	e8 03 80 3c 28       	call   0x283c8008
   5:	00 74 08 4c          	add    %dh,0x4c(%rax,%rcx,1)
   9:	89 e7                	mov    %esp,%edi
   b:	e8 bd 38 9b f7       	call   0xf79b38cd
  10:	4c 89 74 24 18       	mov    %r14,0x18(%rsp)
  15:	49 8b 2c 24          	mov    (%r12),%rbp
  19:	4c 89 e8             	mov    %r13,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	4c 89 ef             	mov    %r13,%rdi
  33:	e8 95 38 9b f7       	call   0xf79b38cd
  38:	4d 8b 75 00          	mov    0x0(%r13),%r14
  3c:	4d                   	rex.WRB
  3d:	8d                   	.byte 0x8d
  3e:	a7                   	cmpsl  %es:(%rdi),%ds:(%rsi)
  3f:	30                   	.byte 0x30