BUG: kernel NULL pointer dereference, address: 0000000000000008
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0 
Oops: Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 1 UID: 0 PID: 2675 Comm: syz.0.281 Not tainted 6.11.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
RIP: 0010:_compound_head include/linux/page-flags.h:240 [inline]
RIP: 0010:put_page include/linux/mm.h:1550 [inline]
RIP: 0010:skb_page_unref include/linux/skbuff_ref.h:44 [inline]
RIP: 0010:__skb_frag_unref include/linux/skbuff_ref.h:57 [inline]
RIP: 0010:skb_release_data+0xf1/0x200 net/core/skbuff.c:1120
Code: 00 0f 84 ab 00 00 00 4b 8d 5c 25 30 45 31 f6 eb 16 49 ff c6 43 0f b6 44 2c 02 48 83 c3 10 49 39 c6 0f 83 8b 00 00 00 48 8b 2b <48> 8b 45 08 a8 01 75 3d 66 90 66 90 83 7d 34 00 0f 84 d8 00 00 00
RSP: 0018:ffffc900000e09f8 EFLAGS: 00010246
RAX: ffff8881022ad440 RBX: ffff8881022ad570 RCX: 0000000000000100
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff888103333e00
RBP: 0000000000000000 R08: 0000000000000029 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881022ad440
R13: 0000000000000100 R14: 0000000000000000 R15: ffff888103333e00
FS:  0000000000000000(0000) GS:ffff888237d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 00000000034aa000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 skb_release_all net/core/skbuff.c:1191 [inline]
 __kfree_skb+0x24/0xa0 net/core/skbuff.c:1205
 tcp_clean_rtx_queue net/ipv4/tcp_input.c:3409 [inline]
 tcp_ack+0x92c/0x14f0 net/ipv4/tcp_input.c:4005
 tcp_rcv_state_process+0x2ba/0xd10 net/ipv4/tcp_input.c:6764
 tcp_v4_do_rcv+0x1c7/0x300 net/ipv4/tcp_ipv4.c:1937
 tcp_v4_rcv+0xdc1/0xf30 net/ipv4/tcp_ipv4.c:2349
 ip_protocol_deliver_rcu+0x125/0x2b0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0xa4/0x100 net/ipv4/ip_input.c:233
 NF_HOOK include/linux/netfilter.h:314 [inline]
 ip_local_deliver+0x6a/0x140 net/ipv4/ip_input.c:254
 NF_HOOK include/linux/netfilter.h:314 [inline]
 ip_rcv+0x46/0x120 net/ipv4/ip_input.c:569
 __netif_receive_skb_one_core net/core/dev.c:5663 [inline]
 __netif_receive_skb+0xa3/0x160 net/core/dev.c:5777
 process_backlog+0x1e9/0x420 net/core/dev.c:6110
 __napi_poll+0x27/0x1c0 net/core/dev.c:6774
 napi_poll net/core/dev.c:6843 [inline]
 net_rx_action+0x275/0x460 net/core/dev.c:6965
 handle_softirqs+0x10c/0x300 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0x4f/0xc0 kernel/softirq.c:637
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0x92/0xb0 arch/x86/kernel/apic/apic.c:1043
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:deref_stack_reg+0x84/0x90 arch/x86/kernel/unwind_orc.c:408
Code: 39 f9 77 21 48 8b 53 10 4c 39 fa 76 18 49 8d 77 08 31 c0 48 39 ce 76 0d 48 39 d6 77 08 49 8b 07 49 89 06 b0 01 5b 41 5e 41 5f <c3> cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900038cf738 EFLAGS: 00000287
RAX: 0000000000000001 RBX: ffffc900038cff48 RCX: ffffc900038d0000
RDX: ffffc900038cff50 RSI: ffffc900038cff48 RDI: ffffc900038cf788
RBP: ffffc900038cf7d8 R08: 0000000000000000 R09: ffffffff83ee6324
R10: 0000000000000000 R11: ffffffff81155640 R12: ffffc900038cff50
R13: 0000000000000001 R14: ffffffff83ee6324 R15: ffffc900038cf788
 unwind_next_frame+0x9d7/0xc50
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x47/0x70 kernel/stacktrace.c:122
 save_stack+0xef/0x140 mm/page_owner.c:156
 __reset_page_owner+0x40/0x140 mm/page_owner.c:297
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_folios+0x5d3/0xae0 mm/page_alloc.c:2660
 folios_put_refs+0x1c1/0x200 mm/swap.c:1039
 free_pages_and_swap_cache+0x1c3/0x1f0 mm/swap_state.c:335
 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:366 [inline]
 tlb_flush_mmu+0x133/0x1a0 mm/mmu_gather.c:373
 tlb_finish_mmu+0x41/0x80 mm/mmu_gather.c:465
 exit_mmap+0x2cd/0x580 mm/mmap.c:3425
 __mmput+0x3d/0x110 kernel/fork.c:1345
 exit_mm+0xaa/0x110 kernel/exit.c:571
 do_exit+0x1eb/0xac0 kernel/exit.c:869
 do_group_exit+0x86/0xa0 kernel/exit.c:1031
 get_signal+0x718/0x7d0 kernel/signal.c:2917
 arch_do_signal_or_restart+0x89/0x2a0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x57/0x1d0 kernel/entry/common.c:218
 do_syscall_64+0x9a/0x170 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6a8b185d19
Code: Unable to access opcode bytes at 0x7f6a8b185cef.
RSP: 002b:00007f6a8bf330e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f6a8b375fa8 RCX: 00007f6a8b185d19
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6a8b375fa8
RBP: 00007f6a8b375fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6a8b375fac
R13: 0000000000000000 R14: 00007f6a8b49f940 R15: 00007f6a8b49fa28
 </TASK>
Modules linked in:
CR2: 0000000000000008
---[ end trace 0000000000000000 ]---
RIP: 0010:_compound_head include/linux/page-flags.h:240 [inline]
RIP: 0010:put_page include/linux/mm.h:1550 [inline]
RIP: 0010:skb_page_unref include/linux/skbuff_ref.h:44 [inline]
RIP: 0010:__skb_frag_unref include/linux/skbuff_ref.h:57 [inline]
RIP: 0010:skb_release_data+0xf1/0x200 net/core/skbuff.c:1120
Code: 00 0f 84 ab 00 00 00 4b 8d 5c 25 30 45 31 f6 eb 16 49 ff c6 43 0f b6 44 2c 02 48 83 c3 10 49 39 c6 0f 83 8b 00 00 00 48 8b 2b <48> 8b 45 08 a8 01 75 3d 66 90 66 90 83 7d 34 00 0f 84 d8 00 00 00
RSP: 0018:ffffc900000e09f8 EFLAGS: 00010246
RAX: ffff8881022ad440 RBX: ffff8881022ad570 RCX: 0000000000000100
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff888103333e00
RBP: 0000000000000000 R08: 0000000000000029 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881022ad440
R13: 0000000000000100 R14: 0000000000000000 R15: ffff888103333e00
FS:  0000000000000000(0000) GS:ffff888237d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 00000000034aa000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	00 0f                	add    %cl,(%rdi)
   2:	84 ab 00 00 00 4b    	test   %ch,0x4b000000(%rbx)
   8:	8d 5c 25 30          	lea    0x30(%rbp,%riz,1),%ebx
   c:	45 31 f6             	xor    %r14d,%r14d
   f:	eb 16                	jmp    0x27
  11:	49 ff c6             	inc    %r14
  14:	43 0f b6 44 2c 02    	movzbl 0x2(%r12,%r13,1),%eax
  1a:	48 83 c3 10          	add    $0x10,%rbx
  1e:	49 39 c6             	cmp    %rax,%r14
  21:	0f 83 8b 00 00 00    	jae    0xb2
  27:	48 8b 2b             	mov    (%rbx),%rbp
* 2a:	48 8b 45 08          	mov    0x8(%rbp),%rax <-- trapping instruction
  2e:	a8 01                	test   $0x1,%al
  30:	75 3d                	jne    0x6f
  32:	66 90                	xchg   %ax,%ax
  34:	66 90                	xchg   %ax,%ax
  36:	83 7d 34 00          	cmpl   $0x0,0x34(%rbp)
  3a:	0f 84 d8 00 00 00    	je     0x118