------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 10953 at lib/refcount.c:25 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25
Modules linked in:
CPU: 1 UID: 0 PID: 10953 Comm: syz.4.1273 Not tainted 6.15.0-syzkaller-08297-ge0797d3b91de #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25
Code: 00 00 e8 19 6f 00 fd 5b 41 5e e9 81 eb a6 06 cc e8 0b 6f 00 fd c6 05 e7 f2 ca 0a 01 90 48 c7 c7 00 19 e2 8b e8 57 5b c4 fc 90 <0f> 0b 90 90 eb d7 e8 eb 6e 00 fd c6 05 c8 f2 ca 0a 01 90 48 c7 c7
RSP: 0018:ffffc90000a08828 EFLAGS: 00010246
RAX: 3d0a1d4b93156500 RBX: 0000000000000002 RCX: ffff88802c0c9e00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc90000a089b0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa66c R12: ffff88805d5ea080
R13: dffffc0000000000 R14: ffff88805d5ea1ec R15: ffff88807d525800
FS: 0000000000000000(0000) GS:ffff888125d64000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c31fcf7 CR3: 000000005d576000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__refcount_add include/linux/refcount.h:-1 [inline]
__refcount_inc include/linux/refcount.h:366 [inline]
refcount_inc include/linux/refcount.h:383 [inline]
get_net include/net/net_namespace.h:268 [inline]
tipc_aead_encrypt net/tipc/crypto.c:821 [inline]
tipc_crypto_xmit+0x1820/0x22c0 net/tipc/crypto.c:1761
tipc_bearer_xmit_skb+0x245/0x400 net/tipc/bearer.c:572
tipc_disc_timeout+0x580/0x6d0 net/tipc/discover.c:338
call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
handle_softirqs+0x286/0x870 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pfn_valid+0x3d8/0x490 include/linux/mmzone.h:2129
Code: ce b0 6f ff bf 01 00 00 00 e8 c4 4c 62 ff 65 8b 1d cd 4b 6d 10 31 ff 89 de e8 c4 ba 91 ff 85 db 74 28 e8 7b b6 91 ff 89 e8 5b <41> 5c 41 5d 41 5e 41 5f 5d e9 da 32 38 09 cc e8 64 b6 91 ff e8 df
RSP: 0018:ffffc9000b357340 EFLAGS: 00000293
RAX: 0000000000000001 RBX: 1ffffd400036e123 RCX: ffff88802c0c9e00
RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff822e715a
R10: dffffc0000000000 R11: fffff9400036e121 R12: dffffc0000000000
R13: 0000000000000008 R14: 0000000000000001 R15: ffff88813fffa5a0
page_table_check_clear+0x21/0x700 mm/page_table_check.c:70
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
get_and_clear_full_ptes include/linux/pgtable.h:714 [inline]
zap_present_folio_ptes mm/memory.c:1501 [inline]
zap_present_ptes mm/memory.c:1586 [inline]
do_zap_pte_range mm/memory.c:1687 [inline]
zap_pte_range mm/memory.c:1731 [inline]
zap_pmd_range mm/memory.c:1823 [inline]
zap_pud_range mm/memory.c:1852 [inline]
zap_p4d_range mm/memory.c:1873 [inline]
unmap_page_range+0x32fd/0x4580 mm/memory.c:1894
unmap_vmas+0x25d/0x3c0 mm/memory.c:1984
exit_mmap+0x245/0xba0 mm/mmap.c:1284
__mmput+0x118/0x420 kernel/fork.c:1381
exit_mm+0x1da/0x2c0 kernel/exit.c:595
do_exit+0x864/0x2550 kernel/exit.c:947
do_group_exit+0x21c/0x2d0 kernel/exit.c:1108
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b95d8e969
Code: Unable to access opcode bytes at 0x7f8b95d8e93f.
RSP: 002b:00007f8b96bbe0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f8b95fb6088 RCX: 00007f8b95d8e969
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8b95fb6088
RBP: 00007f8b95fb6080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8b95fb608c
R13: 0000000000000000 R14: 00007f8b960df940 R15: 00007f8b960dfa28
----------------
Code disassembly (best guess), 4 bytes skipped:
0: bf 01 00 00 00 mov $0x1,%edi
5: e8 c4 4c 62 ff call 0xff624cce
a: 65 8b 1d cd 4b 6d 10 mov %gs:0x106d4bcd(%rip),%ebx # 0x106d4bde
11: 31 ff xor %edi,%edi
13: 89 de mov %ebx,%esi
15: e8 c4 ba 91 ff call 0xff91bade
1a: 85 db test %ebx,%ebx
1c: 74 28 je 0x46
1e: e8 7b b6 91 ff call 0xff91b69e
23: 89 e8 mov %ebp,%eax
25: 5b pop %rbx
* 26: 41 5c pop %r12 <-- trapping instruction
28: 41 5d pop %r13
2a: 41 5e pop %r14
2c: 41 5f pop %r15
2e: 5d pop %rbp
2f: e9 da 32 38 09 jmp 0x938330e
34: cc int3
35: e8 64 b6 91 ff call 0xff91b69e
3a: e8 .byte 0xe8
3b: df .byte 0xdf