------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 4169 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 4169 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: 0018:ffffc90000007848 EFLAGS: 00010246
RAX: bb1ca188d1870000 RBX: 0000000000000002 RCX: ffff88807aef5940
RDX: 0000000000000100 RSI: 0000000080000101 RDI: 0000000000000000
RBP: ffffc900000079b0 R08: dffffc0000000000 R09: ffffed10172067a8
R10: ffffed10172067a8 R11: 1ffff110172067a7 R12: ffff88801f813500
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc9cfd2a6b0 CR3: 000000000be8e000 CR4: 00000000003506f0
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: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
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 3e 14 d3 f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 06 94 a6 f7 65 8b 05 a7 a3 57 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90002f0f340 EFLAGS: 00000206
RAX: bb1ca188d1870000 RBX: 0000000000000a02 RCX: bb1ca188d1870000
RDX: dffffc0000000000 RSI: ffffffff8a0b11c0 RDI: 0000000000000001
RBP: ffffc90002f0f3d8 R08: dffffc0000000000 R09: fffffbfff2c53c33
R10: fffffbfff2c53c33 R11: 1ffffffff2c53c32 R12: dffffc0000000000
R13: ffff888069524000 R14: ffffffff9629e190 R15: 1ffff920005e1e68
__debug_check_no_obj_freed lib/debugobjects.c:982 [inline]
debug_check_no_obj_freed+0x515/0x530 lib/debugobjects.c:1003
free_pages_prepare mm/page_alloc.c:1345 [inline]
free_pcp_prepare mm/page_alloc.c:1391 [inline]
free_unref_page_prepare+0x237/0x6c0 mm/page_alloc.c:3317
free_unref_page_list+0x122/0x7e0 mm/page_alloc.c:3433
release_pages+0x184b/0x1bb0 mm/swap.c:963
__pagevec_release+0x6d/0xe0 mm/swap.c:983
pagevec_release include/linux/pagevec.h:81 [inline]
shmem_undo_range+0x593/0x1840 mm/shmem.c:964
shmem_truncate_range mm/shmem.c:1063 [inline]
shmem_evict_inode+0x20d/0xa00 mm/shmem.c:1145
evict+0x485/0x870 fs/inode.c:647
__dentry_kill+0x431/0x650 fs/dcache.c:586
dentry_kill+0xb8/0x290 fs/dcache.c:-1
dput+0xd8/0x1a0 fs/dcache.c:893
__fput+0x5ee/0x930 fs/file_table.c:319
task_work_run+0x125/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x616/0x20a0 kernel/exit.c:874
do_group_exit+0x12e/0x300 kernel/exit.c:996
__do_sys_exit_group kernel/exit.c:1007 [inline]
__se_sys_exit_group kernel/exit.c:1005 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1005
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: 0033:0x7f19c008b929
Code: Unable to access opcode bytes at RIP 0x7f19c008b8ff.
RSP: 002b:00007ffd130d2108 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f19c010d997 RCX: 00007f19c008b929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000010 R08: 00007ffd130cfea6 R09: 00007ffd130d33c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd130d33c0
R13: 00007f19c010d925 R14: 0000555557ad84a8 R15: 00007ffd130d4490
----------------
Code disassembly (best guess):
0: 74 05 je 0x7
2: e8 3e 14 d3 f7 call 0xf7d31445
7: 48 c7 44 24 20 00 00 movq $0x0,0x20(%rsp)
e: 00 00
10: 9c pushf
11: 8f 44 24 20 pop 0x20(%rsp)
15: f6 44 24 21 02 testb $0x2,0x21(%rsp)
1a: 75 4b jne 0x67
1c: f7 c3 00 02 00 00 test $0x200,%ebx
22: 74 01 je 0x25
24: fb sti
25: bf 01 00 00 00 mov $0x1,%edi
* 2a: e8 06 94 a6 f7 call 0xf7a69435 <-- trapping instruction
2f: 65 8b 05 a7 a3 57 76 mov %gs:0x7657a3a7(%rip),%eax # 0x7657a3dd
36: 85 c0 test %eax,%eax
38: 74 3c je 0x76
3a: 48 rex.W
3b: c7 .byte 0xc7
3c: 04 24 add $0x24,%al
3e: 0e (bad)
3f: 36 ss