------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: lib/refcount.c:28 at refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28, CPU#0: swapper/0/0
Modules linked in:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28
Code: 64 80 89 0b 67 48 0f b9 3a eb 4a e8 a8 a4 13 fd 48 8d 3d 61 80 89 0b 67 48 0f b9 3a eb 37 e8 95 a4 13 fd 48 8d 3d 5e 80 89 0b <67> 48 0f b9 3a eb 24 e8 82 a4 13 fd 48 8d 3d 5b 80 89 0b 67 48 0f
RSP: 0000:ffffc90000007c68 EFLAGS: 00010246
RAX: ffffffff84b21fcb RBX: 0000000000000003 RCX: ffffffff8e692ec0
RDX: 0000000000000100 RSI: ffffffff8f10fa60 RDI: ffffffff903ba030
RBP: ffffc90000007d70 R08: ffffffff8e692ec0 R09: 0000000000000005
R10: 0000000000000004 R11: 0000000000000100 R12: 0000000000000000
R13: 00000000ffffb730 R14: ffff8880339dd020 R15: ffff8880339dd1b8
FS:  0000000000000000(0000) GS:ffff88812528a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000008010f018 CR3: 00000000353c2000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x22a/0x840 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: ab 7d 02 e9 93 f7 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 a1 20 00 fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0000:ffffffff8e607dc0 EFLAGS: 00000242
RAX: 000000000013af61 RBX: ffffffff819a958a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8dfa6b05 RDI: ffffffff8c28af60
RBP: ffffffff8e607eb0 R08: ffff8880b86339db R09: 1ffff110170c673b
R10: dffffc0000000000 R11: ffffed10170c673c R12: 0000000000000000
R13: 1ffffffff1cd25d8 R14: 0000000000000000 R15: 1ffffffff1cd25d8
 arch_safe_halt arch/x86/kernel/process.c:766 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
 rest_init+0x2de/0x300 init/main.c:762
 start_kernel+0x38a/0x3e0 init/main.c:1220
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x147
 </TASK>
----------------
Code disassembly (best guess):
   0:	64 80 89 0b 67 48 0f 	orb    $0xb9,%fs:0xf48670b(%rcx)
   7:	b9
   8:	3a eb                	cmp    %bl,%ch
   a:	4a e8 a8 a4 13 fd    	rex.WX call 0xfd13a4b8
  10:	48 8d 3d 61 80 89 0b 	lea    0xb898061(%rip),%rdi        # 0xb898078
  17:	67 48 0f b9 3a       	ud1    (%edx),%rdi
  1c:	eb 37                	jmp    0x55
  1e:	e8 95 a4 13 fd       	call   0xfd13a4b8
  23:	48 8d 3d 5e 80 89 0b 	lea    0xb89805e(%rip),%rdi        # 0xb898088
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	eb 24                	jmp    0x55
  31:	e8 82 a4 13 fd       	call   0xfd13a4b8
  36:	48 8d 3d 5b 80 89 0b 	lea    0xb89805b(%rip),%rdi        # 0xb898098
  3d:	67                   	addr32
  3e:	48                   	rex.W
  3f:	0f                   	.byte 0xf