------------[ 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: syz.3.189/6722
Modules linked in:
CPU: 0 UID: 0 PID: 6722 Comm: syz.3.189 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
RIP: 0010:refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28
Code: c4 0a 59 0b 67 48 0f b9 3a eb 4a e8 c8 ce 23 fd 48 8d 3d c1 0a 59 0b 67 48 0f b9 3a eb 37 e8 b5 ce 23 fd 48 8d 3d be 0a 59 0b <67> 48 0f b9 3a eb 24 e8 a2 ce 23 fd 48 8d 3d bb 0a 59 0b 67 48 0f
RSP: 0018:ffffc90000007c88 EFLAGS: 00010246
RAX: ffffffff84a0a89b RBX: 0000000000000003 RCX: ffff88803065db80
RDX: 0000000000000100 RSI: ffffffff8ece7500 RDI: ffffffff8ff9b360
RBP: ffffc90000007d90 R08: ffff88803065db80 R09: 0000000000000005
R10: 0000000000000004 R11: 0000000000000100 R12: 0000000000000000
R13: 00000000ffffb5f0 R14: ffff8880325fc020 R15: ffff8880325fc1b8
FS:  00007f17af9f66c0(0000) GS:ffff8881256f5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f17af9d5d58 CR3: 000000001de9c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_timer_fn+0x192/0x5a0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x714/0x23c0 arch/x86/kernel/unwind_orc.c:527
Code: 24 40 0f b6 04 28 84 c0 48 89 54 24 08 48 89 34 24 0f 85 3d 16 00 00 4c 89 e0 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 53 16 00 00 <0f> b7 1e c1 eb 0b 80 e3 01 48 8b 44 24 28 0f b6 04 28 84 c0 4c 8b
RSP: 0018:ffffc90003fcf838 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff90105db8 RCX: ffffffff90105dbc
RDX: ffffffff909037ee RSI: ffffffff909037f2 RDI: ffffffff8c073920
RBP: dffffc0000000000 R08: 0000000000000014 R09: ffffffff8e55a360
R10: ffffc90003fcf448 R11: ffffffff81afb170 R12: ffffffff909037f3
R13: ffffc90003fcf958 R14: ffffc90003fcf908 R15: ffffffff81759195
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x370/0x6e0 mm/slub.c:5270
 sk_prot_alloc+0x57/0x210 net/core/sock.c:2239
 sk_alloc+0x3a/0x390 net/core/sock.c:2301
 inet_create+0x7a0/0x1000 net/ipv4/af_inet.c:328
 __sock_create+0x4b2/0x9d0 net/socket.c:1605
 sock_create net/socket.c:1663 [inline]
 __sys_socket_create net/socket.c:1700 [inline]
 __sys_socket+0xd6/0x1b0 net/socket.c:1747
 __do_sys_socket net/socket.c:1761 [inline]
 __se_sys_socket net/socket.c:1759 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1759
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f17b179aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f17af9f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 00007f17b1a15fa0 RCX: 00007f17b179aeb9
RDX: 0000000000000084 RSI: 0000000000000001 RDI: 0000000000000002
RBP: 00007f17b1808c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f17b1a16038 R14: 00007f17b1a15fa0 R15: 00007ffc4d289b68
 </TASK>
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	0a 59 0b             	or     0xb(%rcx),%bl
   3:	67 48 0f b9 3a       	ud1    (%edx),%rdi
   8:	eb 4a                	jmp    0x54
   a:	e8 c8 ce 23 fd       	call   0xfd23ced7
   f:	48 8d 3d c1 0a 59 0b 	lea    0xb590ac1(%rip),%rdi        # 0xb590ad7
  16:	67 48 0f b9 3a       	ud1    (%edx),%rdi
  1b:	eb 37                	jmp    0x54
  1d:	e8 b5 ce 23 fd       	call   0xfd23ced7
  22:	48 8d 3d be 0a 59 0b 	lea    0xb590abe(%rip),%rdi        # 0xb590ae7
* 29:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2e:	eb 24                	jmp    0x54
  30:	e8 a2 ce 23 fd       	call   0xfd23ced7
  35:	48 8d 3d bb 0a 59 0b 	lea    0xb590abb(%rip),%rdi        # 0xb590af7
  3c:	67                   	addr32
  3d:	48                   	rex.W
  3e:	0f                   	.byte 0xf