syzbot

BUG: kernel NULL pointer dereference, address: 0000000000000649
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0 
Oops: Oops: 0002 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 26529 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:llc_ui_setsockopt+0x4e1/0x5f0 net/llc/af_llc.c:-1
Code: a1 f8 eb 4b e8 c0 dc 3d f8 4c 6b f3 64 49 8d 9f a0 06 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 df 46 a1 f8 <4c> 89 33 eb 23 e8 95 dc 3d f8 4d 8d b7 0d 07 00 00 4c 89 f0 48 c1
RSP: 0018:ffffc90000a08b98 EFLAGS: 00010246
RAX: 00000000000000c9 RBX: 0000000000000649 RCX: ffff8880815d3c00
RDX: 0000000000000100 RSI: ffffffff8be33660 RDI: ffff88805676a410
RBP: ffffc90000a08c90 R08: ffffffff8fa38437 R09: 1ffffffff1f47086
R10: dffffc0000000000 R11: ffffffff8981cd90 R12: 1ffff92000141178
R13: ffff88805676a410 R14: 0000000000000001 R15: 0000000000000001
FS:  0000555568f28500(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000649 CR3: 000000007e390000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 expire_timers kernel/time/timer.c:1798 [inline]
 __run_timers kernel/time/timer.c:2372 [inline]
 __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
 run_timer_base kernel/time/timer.c:2393 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:notifier_call_chain+0x90/0x3e0 kernel/notifier.c:75
Code: 86 c2 31 00 45 31 ed e9 4d 03 00 00 48 8b 04 24 48 c1 e8 03 48 89 44 24 18 49 8d 7c 24 08 48 89 f8 48 c1 e8 03 42 80 3c 30 00 <74> 05 e8 a9 2b 95 00 49 8b 44 24 08 48 89 44 24 08 4d 89 e7 49 c1
RSP: 0018:ffffc9000c186bb8 EFLAGS: 00000246
RAX: 1ffffffff1ee9339 RBX: dffffc0000000000 RCX: ffff8880815d3c00
RDX: 0000000000000000 RSI: 00000000ffffffb3 RDI: ffffffff8f7499c8
RBP: 00000000ffffffb3 R08: ffffffff8fa38437 R09: 1ffffffff1f47086
R10: dffffc0000000000 R11: ffffffff8aaab220 R12: ffffffff8f7499c0
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffffffff1ee75f4
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 register_netdevice+0x1608/0x1ae0 net/core/dev.c:11244
 veth_newlink+0x5cc/0xa50 drivers/net/veth.c:1884
 rtnl_newlink_create+0x30d/0xb00 net/core/rtnetlink.c:3825
 __rtnl_newlink net/core/rtnetlink.c:3942 [inline]
 rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4057
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6946
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:729
 __sys_sendto+0x3bd/0x520 net/socket.c:2228
 __do_sys_sendto net/socket.c:2235 [inline]
 __se_sys_sendto net/socket.c:2231 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2231
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f90ec790a7c
Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b
RSP: 002b:00007ffd410c5380 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f90ed4e4620 RCX: 00007f90ec790a7c
RDX: 0000000000000068 RSI: 00007f90ed4e4670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffd410c53d4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f90ed4e4670 R15: 0000000000000000
 </TASK>
Modules linked in:
CR2: 0000000000000649
---[ end trace 0000000000000000 ]---
RIP: 0010:llc_ui_setsockopt+0x4e1/0x5f0 net/llc/af_llc.c:-1
Code: a1 f8 eb 4b e8 c0 dc 3d f8 4c 6b f3 64 49 8d 9f a0 06 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 df 46 a1 f8 <4c> 89 33 eb 23 e8 95 dc 3d f8 4d 8d b7 0d 07 00 00 4c 89 f0 48 c1
RSP: 0018:ffffc90000a08b98 EFLAGS: 00010246
RAX: 00000000000000c9 RBX: 0000000000000649 RCX: ffff8880815d3c00
RDX: 0000000000000100 RSI: ffffffff8be33660 RDI: ffff88805676a410
RBP: ffffc90000a08c90 R08: ffffffff8fa38437 R09: 1ffffffff1f47086
R10: dffffc0000000000 R11: ffffffff8981cd90 R12: 1ffff92000141178
R13: ffff88805676a410 R14: 0000000000000001 R15: 0000000000000001
FS:  0000555568f28500(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000649 CR3: 000000007e390000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	a1 f8 eb 4b e8 c0 dc 	movabs 0xf83ddcc0e84bebf8,%eax
   7:	3d f8
   9:	4c 6b f3 64          	imul   $0x64,%rbx,%r14
   d:	49 8d 9f a0 06 00 00 	lea    0x6a0(%r15),%rbx
  14:	48 89 d8             	mov    %rbx,%rax
  17:	48 c1 e8 03          	shr    $0x3,%rax
  1b:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
  20:	74 08                	je     0x2a
  22:	48 89 df             	mov    %rbx,%rdi
  25:	e8 df 46 a1 f8       	call   0xf8a14709
* 2a:	4c 89 33             	mov    %r14,(%rbx) <-- trapping instruction
  2d:	eb 23                	jmp    0x52
  2f:	e8 95 dc 3d f8       	call   0xf83ddcc9
  34:	4d 8d b7 0d 07 00 00 	lea    0x70d(%r15),%r14
  3b:	4c 89 f0             	mov    %r14,%rax
  3e:	48                   	rex.W
  3f:	c1                   	.byte 0xc1