------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: lib/refcount.c:19 at refcount_warn_saturate+0x13a/0x1d0 lib/refcount.c:19, CPU#1: syz.1.2156/18040
Modules linked in:
CPU: 1 UID: 0 PID: 18040 Comm: syz.1.2156 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:refcount_warn_saturate+0x13a/0x1d0 lib/refcount.c:19
Code: 20 cf be 8b e8 67 9a f3 fc 90 0f 0b 90 90 eb b7 e8 8b 7b 31 fd c6 05 b5 a0 d7 0a 01 90 48 c7 c7 60 ce be 8b e8 47 9a f3 fc 90 <0f> 0b 90 90 eb 97 e8 6b 7b 31 fd c6 05 99 a0 d7 0a 01 90 48 c7 c7
RSP: 0018:ffffc90003217568 EFLAGS: 00010246
RAX: d81d4f740f2edc00 RBX: 0000000000000000 RCX: ffff8880314a0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc90003217688 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bba720 R12: ffff888027668940
R13: 1ffff92000642ec0 R14: ffff888027668940 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125fba000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555571a2f7d0 CR3: 000000004aa82000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __refcount_add_not_zero include/linux/refcount.h:187 [inline]
 refcount_add_not_zero include/linux/refcount.h:212 [inline]
 __vma_enter_locked+0x593/0x5d0 mm/mmap_lock.c:67
 __vma_start_write+0x23/0x140 mm/mmap_lock.c:99
 vma_start_write include/linux/mmap_lock.h:213 [inline]
 free_pgtables+0x55d/0x9d0 mm/memory.c:398
 exit_mmap+0x431/0xb40 mm/mmap.c:1288
 __mmput+0x118/0x430 kernel/fork.c:1173
 exit_mm+0x1da/0x2c0 kernel/exit.c:581
 do_exit+0x658/0x2310 kernel/exit.c:959
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
 get_signal+0x1285/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:75 [inline]
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
 irqentry_exit+0x177/0x660 kernel/entry/common.c:196
 exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f6b380509e6
Code: Unable to access opcode bytes at 0x7f6b380509bc.
RSP: 002b:00007f6b390734a0 EFLAGS: 00010206
RAX: 0000000000693001 RBX: 00007f6b39073540 RCX: 00000000000000e6
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f6b390735e0
RBP: 0000000000000102 R08: 00007f6b2de00000 R09: 0000000000693000
R10: 0000000000000000 R11: 00007f6b39073550 R12: 0000000000000001
R13: 00007f6b3822fc40 R14: 0000000000000000 R15: 00007f6b390735e0
 </TASK>