Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 7638 Comm: syz.1.461 Not tainted 6.16.0-rc3-next-20250623-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pidfs_free_pid+0xaf/0x140 fs/pidfs.c:162
Code: f0 ff ff 73 e4 43 80 3c 3c 00 74 08 4c 89 f7 e8 a7 1b de ff 49 83 3e 00 0f 85 84 00 00 00 e8 08 f2 79 ff 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 82 1b de ff 4c 8b 33 4d 85 f6 74
RSP: 0018:ffffc90000a08b90 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88807d33da00
RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff888027ce4070
RBP: 0000000000000001 R08: ffff888027ce4003 R09: 1ffff11004f9c800
R10: dffffc0000000000 R11: ffffed1004f9c801 R12: 1ffff11004f9c80d
R13: ffffffff81a83684 R14: ffff888027ce4068 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000000df38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000005325
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 put_pid+0x9c/0x130 kernel/pid.c:103
 rcu_do_batch kernel/rcu/tree.c:2582 [inline]
 rcu_core+0xca5/0x1710 kernel/rcu/tree.c:2838
 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:spin_lock include/linux/spinlock.h:351 [inline]
RIP: 0010:__pte_offset_map_lock+0x136/0x210 mm/pgtable-generic.c:402
Code: 2c 2f 48 83 c5 28 48 89 e8 48 c1 e8 03 49 be 00 00 00 00 00 fc ff df 42 80 3c 30 00 74 08 48 89 ef e8 1e 25 13 00 48 8b 6d 00 <48> 89 ef e8 02 30 5f 09 43 80 3c 34 00 74 08 48 89 df e8 03 25 13
RSP: 0018:ffffc90004d77328 EFLAGS: 00000246
RAX: 1ffffd40002f80bd RBX: ffff888052ae8c00 RCX: ffff88807d33da00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888062f7d7e0 R08: 0000000000000000 R09: ffffffff8210c9e9
R10: ffffc90004d775a0 R11: fffff520009aeeb6 R12: 1ffff1100a55d180
R13: 00000000017c05c0 R14: dffffc0000000000 R15: ffffea0000000000
 pte_offset_map_lock include/linux/mm.h:3034 [inline]
 zap_pte_range mm/memory.c:1739 [inline]
 zap_pmd_range mm/memory.c:1845 [inline]
 zap_pud_range mm/memory.c:1874 [inline]
 zap_p4d_range mm/memory.c:1895 [inline]
 unmap_page_range+0xc06/0x41c0 mm/memory.c:1916
 unmap_single_vma mm/memory.c:1959 [inline]
 unmap_vmas+0x399/0x580 mm/memory.c:2003
 exit_mmap+0x248/0xb50 mm/mmap.c:1284
 __mmput+0x118/0x420 kernel/fork.c:1120
 exit_mm+0x1da/0x2c0 kernel/exit.c:581
 do_exit+0x648/0x2300 kernel/exit.c:947
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1100
 get_signal+0x1286/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbe9138e929
Code: Unable to access opcode bytes at 0x7fbe9138e8ff.
RSP: 002b:00007fbe921a4fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: fffffffffffffffc RBX: 00007fbe915b5fa0 RCX: 00007fbe9138e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062000000
RBP: 00007fbe91410b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fbe915b5fa0 R15: 00007fff0860a358
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:pidfs_free_pid+0xaf/0x140 fs/pidfs.c:162
Code: f0 ff ff 73 e4 43 80 3c 3c 00 74 08 4c 89 f7 e8 a7 1b de ff 49 83 3e 00 0f 85 84 00 00 00 e8 08 f2 79 ff 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 82 1b de ff 4c 8b 33 4d 85 f6 74
RSP: 0018:ffffc90000a08b90 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88807d33da00
RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff888027ce4070
RBP: 0000000000000001 R08: ffff888027ce4003 R09: 1ffff11004f9c800
R10: dffffc0000000000 R11: ffffed1004f9c801 R12: 1ffff11004f9c80d
R13: ffffffff81a83684 R14: ffff888027ce4068 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000000df38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000005325
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	f0 ff                	lock (bad)
   2:	ff 73 e4             	push   -0x1c(%rbx)
   5:	43 80 3c 3c 00       	cmpb   $0x0,(%r12,%r15,1)
   a:	74 08                	je     0x14
   c:	4c 89 f7             	mov    %r14,%rdi
   f:	e8 a7 1b de ff       	call   0xffde1bbb
  14:	49 83 3e 00          	cmpq   $0x0,(%r14)
  18:	0f 85 84 00 00 00    	jne    0xa2
  1e:	e8 08 f2 79 ff       	call   0xff79f22b
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 82 1b de ff       	call   0xffde1bbb
  39:	4c 8b 33             	mov    (%rbx),%r14
  3c:	4d 85 f6             	test   %r14,%r14
  3f:	74                   	.byte 0x74