------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 6427 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 6427 Comm: syz-executor Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Code: 09 01 48 c7 c7 40 6b 59 8a e8 dd 27 bb 05 0f 0b eb e0 e8 04 42 9c fd c6 05 ae 8f 79 09 01 48 c7 c7 80 6a 59 8a e8 c1 27 bb 05 <0f> 0b eb c4 e8 e8 41 9c fd c6 05 93 8f 79 09 01 48 c7 c7 e0 6a 59
RSP: 0000:ffffc90000dd0848 EFLAGS: 00010246
RAX: 4b7725a7a31d4100 RBX: 0000000000000002 RCX: ffff888026768000
RDX: 0000000000000100 RSI: 0000000000000101 RDI: 0000000000000000
RBP: ffffc90000dd09b0 R08: dffffc0000000000 R09: fffff520001ba06d
R10: fffff520001ba06d R11: 1ffff920001ba06c R12: ffff88801a793500
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000
FS:  000055557a2b7500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000001e000 CR3: 00000000798bb000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __refcount_add include/linux/refcount.h:-1 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 get_net include/net/net_namespace.h:252 [inline]
 tipc_aead_encrypt net/tipc/crypto.c:832 [inline]
 tipc_crypto_xmit+0x1949/0x2560 net/tipc/crypto.c:1772
 tipc_bearer_xmit_skb+0x228/0x3c0 net/tipc/bearer.c:574
 tipc_disc_timeout+0x568/0x6b0 net/tipc/discover.c:338
 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:pvclock_clocksource_read+0x1eb/0x760 arch/x86/kernel/pvclock.c:77
Code: b6 04 20 84 c0 48 8b 54 24 38 4c 8b 74 24 28 0f 85 bf 02 00 00 49 8b 2a 48 8b 44 24 58 42 0f b6 04 20 84 c0 0f 85 06 03 00 00 <44> 0f b6 7f 1d 42 0f b6 04 22 84 c0 0f 85 4f 03 00 00 43 0f b6 04
RSP: 0000:ffffc9000333f5d8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000000001
RDX: 1ffffffff1dd6008 RSI: ffffffff8eeb005c RDI: ffffffff8eeb0040
RBP: 00000000196d9dbd R08: ffffffff8eeb0048 R09: ffffffff8eeb0058
R10: ffffffff8eeb0050 R11: ffffffff8eeb0043 R12: dffffc0000000000
R13: 00000034a9b9287f R14: 1ffffffff1dd6008 R15: 0000000000000000
 kvm_clock_read arch/x86/kernel/kvmclock.c:79 [inline]
 kvm_sched_clock_read+0x14/0x40 arch/x86/kernel/kvmclock.c:91
 sched_clock_cpu+0x15/0x3c0 kernel/sched/clock.c:371
 local_clock include/linux/sched/clock.h:84 [inline]
 __set_page_owner_handle mm/page_owner.c:164 [inline]
 __set_page_owner+0x174/0x2d0 mm/page_owner.c:182
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5474
 vm_area_alloc_pages mm/vmalloc.c:2869 [inline]
 __vmalloc_area_node mm/vmalloc.c:2925 [inline]
 __vmalloc_node_range+0x4b2/0x8b0 mm/vmalloc.c:3030
 vmalloc_user+0x70/0x80 mm/vmalloc.c:3166
 kcov_mmap+0x27/0x120 kernel/kcov.c:474
 call_mmap include/linux/fs.h:2177 [inline]
 mmap_file+0x5d/0xb0 mm/util.c:1092
 __mmap_region mm/mmap.c:1784 [inline]
 mmap_region+0xd0d/0x15e0 mm/mmap.c:2921
 do_mmap+0x77a/0xdf0 mm/mmap.c:1574
 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:551
 ksys_mmap_pgoff+0x542/0x780 mm/mmap.c:1623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f633944a963
Code: f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 41 89 ca 41 f7 c1 ff 0f 00 00 75 14 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 25 c3 0f 1f 40 00 48 c7 c0 a8 ff ff ff 64 c7
RSP: 002b:00007ffd8b62e828 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f6339672118 RCX: 00007f633944a963
RDX: 0000000000000003 RSI: 0000000000400000 RDI: 00007f63386b9000
RBP: 00007f6339672118 R08: 00000000000000d9 R09: 0000000000000000
R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	b6 04                	mov    $0x4,%dh
   2:	20 84 c0 48 8b 54 24 	and    %al,0x24548b48(%rax,%rax,8)
   9:	38 4c 8b 74          	cmp    %cl,0x74(%rbx,%rcx,4)
   d:	24 28                	and    $0x28,%al
   f:	0f 85 bf 02 00 00    	jne    0x2d4
  15:	49 8b 2a             	mov    (%r10),%rbp
  18:	48 8b 44 24 58       	mov    0x58(%rsp),%rax
  1d:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
  22:	84 c0                	test   %al,%al
  24:	0f 85 06 03 00 00    	jne    0x330
* 2a:	44 0f b6 7f 1d       	movzbl 0x1d(%rdi),%r15d <-- trapping instruction
  2f:	42 0f b6 04 22       	movzbl (%rdx,%r12,1),%eax
  34:	84 c0                	test   %al,%al
  36:	0f 85 4f 03 00 00    	jne    0x38b
  3c:	43                   	rex.XB
  3d:	0f                   	.byte 0xf
  3e:	b6 04                	mov    $0x4,%dh