Kernel bug: general protection fault in lec_arp_clear_vccs
Subsystem: net
Status: fixed

Crash report:
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: 8024 Comm: syz.3.396 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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 5d f6 62 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 35 f6 62 f7 4d 8b 75 00 4d 8d a7 30
RSP: 0018:ffffc9000cc67bc8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff88807efa2400 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffffff8c2764e0 RDI: ffff88807efa2400
RBP: ffff888057c3c000 R08: ffffffff8ef0f2f3 R09: 1ffffffff1de1e5e
R10: dffffc0000000000 R11: fffffbfff1de1e5f R12: ffff88803352e650
R13: 0000000000000000 R14: ffff88807efa2430 R15: ffff88803352e000
FS:  0000555590f50500(0000) GS:ffff8881254b0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffef315f148 CR3: 00000000722fa000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 lec_vcc_close net/atm/lec.c:2183 [inline]
 lec_push+0x3cb/0x19d0 net/atm/lec.c:594
 vcc_destroy_socket net/atm/common.c:183 [inline]
 vcc_release+0x15f/0x580 net/atm/common.c:205
 __sock_release net/socket.c:662 [inline]
 sock_close+0xc3/0x240 net/socket.c:1455
 __fput+0x44f/0xa70 fs/file_table.c:469
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __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 include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f005119bf79
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff437a3bc8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f0051417da0 RCX: 00007f005119bf79
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f0051417da0 R08: 00007f0051416128 R09: 0000000000000000
R10: 000000000003fd6c R11: 0000000000000246 R12: 000000000002c374
R13: 00007f0051415fac R14: 000000000002c122 R15: 00007fff437a3cd0
 </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 5d f6 62 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 35 f6 62 f7 4d 8b 75 00 4d 8d a7 30
RSP: 0018:ffffc9000cc67bc8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff88807efa2400 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffffff8c2764e0 RDI: ffff88807efa2400
RBP: ffff888057c3c000 R08: ffffffff8ef0f2f3 R09: 1ffffffff1de1e5e
R10: dffffc0000000000 R11: fffffbfff1de1e5f R12: ffff88803352e650
R13: 0000000000000000 R14: ffff88807efa2430 R15: ffff88803352e000
FS:  0000555590f50500(0000) GS:ffff8881254b0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffef315f148 CR3: 00000000722fa000 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 5d f6 62 f7       	call   0xf762f66d
  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 35 f6 62 f7       	call   0xf762f66d
  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