------------[ cut here ]------------
anon_vma->num_active_vmas
WARNING: mm/rmap.c:528 at unlink_anon_vmas+0x6c5/0x730 mm/rmap.c:528, CPU#1: syz.3.115/6303
Modules linked in:
CPU: 1 UID: 0 PID: 6303 Comm: syz.3.115 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:unlink_anon_vmas+0x6c5/0x730 mm/rmap.c:528
Code: 08 00 48 3b 6c 24 18 74 29 e8 37 d0 a9 ff 49 89 ee e9 cf fd ff ff e8 2a d0 a9 ff 90 0f 0b 90 e9 4d fe ff ff e8 1c d0 a9 ff 90 <0f> 0b 90 e9 81 fe ff ff e8 0e d0 a9 ff eb 05 e8 07 d0 a9 ff 48 83
RSP: 0018:ffffc90006b5f888 EFLAGS: 00010293
RAX: ffffffff821c38b4 RBX: ffff88807e1c0220 RCX: ffff888033809e80
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000000
RBP: ffff888077ae7a30 R08: ffff88807e1c022f R09: 1ffff1100fc38045
R10: dffffc0000000000 R11: ffffed100fc38046 R12: ffffffffffffffff
R13: 1ffff1100670e5d0 R14: ffff888033872e80 R15: ffff88807e1c0220
FS:  0000000000000000(0000) GS:ffff8881250f5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30b63fff CR3: 000000003657a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 free_pgtables+0x836/0xb70 mm/memory.c:414
 exit_mmap+0x490/0xa10 mm/mmap.c:1314
 __mmput+0x118/0x430 kernel/fork.c:1179
 exit_mm+0x18e/0x250 kernel/exit.c:581
 do_exit+0x8b9/0x2580 kernel/exit.c:962
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1116
 __do_sys_exit_group kernel/exit.c:1127 [inline]
 __se_sys_exit_group kernel/exit.c:1125 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1125
 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc63c19c799
Code: Unable to access opcode bytes at 0x7fc63c19c76f.
RSP: 002b:00007ffd8819ebd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc63c19c799
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd8819ec3c R08: 0000000000000000 R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000018
R13: 00000000000927c0 R14: 00000000000260b4 R15: 00007ffd8819ec90
 </TASK>