------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 28776 at lib/refcount.c:25 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25
Modules linked in:
CPU: 0 UID: 0 PID: 28776 Comm: syz.8.5920 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:ffffc90000007828 EFLAGS: 00010246
RAX: 17bb66c9b7b7c600 RBX: 0000000000000002 RCX: ffff888027aabc00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc900000079b0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa66c R12: ffff888028090000
R13: dffffc0000000000 R14: ffff88802809016c R15: ffff88805d18a400
FS: 0000000000000000(0000) GS:ffff888125c64000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000001b8030 CR3: 000000004514a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 3a810b1eb6134bdc DR6: 00000000ffff0ff0 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:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:412
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 0b 87 cc f5 cc
RSP: 0018:ffffc9000d057368 EFLAGS: 00000293
RAX: ffffffff822e5a8d RBX: 0000000000011398 RCX: ffff888027aabc00
RDX: 0000000000000000 RSI: 0000000000001399 RDI: 0000000000000000
RBP: ffff88801b061f80 R08: ffff88801b061fcf R09: 1ffff1100360c3f9
R10: dffffc0000000000 R11: ffffed100360c3fa R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000011399 R15: ffff88801b061fc8
page_ext_next include/linux/page_ext.h:108 [inline]
page_ext_iter_next include/linux/page_ext.h:156 [inline]
page_table_check_clear+0x3bd/0x700 mm/page_table_check.c:78
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: 0033:0x7f8fb4d8e969
Code: Unable to access opcode bytes at 0x7f8fb4d8e93f.
RSP: 002b:00007f8fb5c840e8 EFLAGS: 00000246
ORIG_RAX: 00000000000000ca
RAX: 0000000000000000 RBX: 00007f8fb4fb6088 RCX: 00007f8fb4d8e969
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8fb4fb6088
RBP: 00007f8fb4fb6080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8fb4fb608c
R13: 0000000000000000 R14: 00007f8fb50df940 R15: 00007f8fb50dfa28
----------------
Code disassembly (best guess):
0: cc int3
1: cc int3
2: cc int3
3: cc int3
4: cc int3
5: cc int3
6: cc int3
7: cc int3
8: cc int3
9: cc int3
a: cc int3
b: cc int3
c: cc int3
d: cc int3
e: cc int3
f: cc int3
10: cc int3
11: cc int3
12: cc int3
13: cc int3
14: cc int3
15: cc int3
16: cc int3
17: cc int3
18: cc int3
19: cc int3
1a: cc int3
1b: cc int3
1c: cc int3
1d: cc int3
1e: cc int3
1f: cc int3
20: cc int3
21: cc int3
22: cc int3
23: cc int3
24: cc int3
25: cc int3
26: cc int3
27: cc int3
28: cc int3
29: cc int3
* 2a: c3 ret <-- trapping instruction
2b: cc int3
2c: 90 nop
2d: 90 nop
2e: 90 nop
2f: 90 nop
30: 90 nop
31: 90 nop
32: 90 nop
33: 90 nop
34: 90 nop
35: 90 nop
36: 90 nop
37: 90 nop
38: 90 nop
39: 90 nop
3a: e9 0b 87 cc f5 jmp 0xf5cc874a
3f: cc int3